e-puck2 and e-puck2 PC side development: Difference between pages

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=Hardware=
[{{fullurl:e-puck2}} e-puck2 main wiki]<br/>
==Overview==
<span class="plainlinks">[http://www.gctronic.com/doc/images/e-puck2-overview.png <img width=500 src="http://www.gctronic.com/doc/images/e-puck2-overview_small.png">]</span>
<span class="plainlinks">[http://projects.gctronic.com/epuck2/wiki_images/e-puck2-features.png <img width=600 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2-features_small.png">]</span><br/>


The following figures show the main components offered by the e-puck2 robot and where they are physically placed:<br/>
=Robot configuration=
<span class="plainlinks">[http://projects.gctronic.com/epuck2/wiki_images/epuck2-components-position.png <img width=800 src="http://projects.gctronic.com/epuck2/wiki_images/epuck2-components-position_small.png">]</span><br/>
This section explains how to configure the robot based on the communication channel you will use for your developments, thus you need to read only one of the following sections, but it would be better if you spend a bit of time reading them all in order to have a full understanding of the available configurations.
==Bluetooth and USB==
The main microcontroller and radio module of the robot are initially programmed with firmwares that together support Bluetooth and USB communication.<br/>


==Specifications==
If the main microcontroller and radio module aren't programmed with the standard firmware or if you want to be sure to have the last firmwares on the robot, you need to program them with the last standard firmware:
The e-puck2 robot maintains full compatibility with its predecessor e-puck (e-puck HWRev 1.3 is considered in the following table):
* for the main microcontroller, refer to section [http://www.gctronic.com/doc/index.php?title=e-puck2#Firmware_update Firmware update].<br/>
{| border="1"
* for the radio module, refer to section []
|'''Feature'''
|'''e-puck1.3'''
|'''e-puck2'''
|'''Compatibility'''
|'''Additional'''
|-
|Size, weight
|70 mm diameter, 55 mm height, 150 g
|Same form factor: 70 mm diameter, 45 mm, 130 g
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|No e-jumper required
|-
|Battery, autonomy
|LiIPo rechargeable battery (external charger), 1800 mAh. <br/>About 3 hours autonomy. Recharging time about 2-3h.
|Same battery; USB charging, recharging time about 2.5h.
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|USB charging
|-
|Processor
|16-bit dsPIC30F6014A @ 60MHz (15 MIPS), DSP core for signal processing
|32-bit STM32F407 @ 168 MHz (210 DMIPS), DSP and FPU, DMA
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|~10 times faster
|-
|Memory
|RAM: 8 KB; Flash: 144 KB
|RAM: 192 KB; Flash: 1024 KB
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|RAM: 24x more capable<br/>Flash:~7x more capable
|-
|Motors
|2 stepper motors with a 50:1 reduction gear; 20 steps per revolution; about 0.13 mm resolution
|Same motors
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Wheels
|Wheels diamater = 41 mm <br/>Distance between wheels = 53 mm
|Same wheels
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Speed
|Max: 1000 steps/s (about 12.9 cm/s)
|Max: 1200 steps/s (about 15.4 cm/s)
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|20% faster
|-
|Mechanical structure
|Transparent plastic body supporting PCBs, battery and motors
|Same mechanics
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Distance sensor
|8 infra-red sensors measuring ambient light and proximity of objects up to 6 cm
|Same infra-red sensors <br/>Front real distance sensor, Time of fight (ToF), up to 2 meter.
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|ToF sensor
|-
|IMU
|3D accelerometer and 3D gyro
|3D accelerometer, 3D gyro, 3D magnetometer
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|3D magnetometer
|-
|Camera
|VGA color camera; typical use: 52x39 or 480x1
|Same camera; typical use: 160x120
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|Bigger images handling
|-
|Audio
|3 omni-directional microphones for sound localization<br/>speaker capable of playing WAV or tone sounds
|4 omni-directional microhpones (digital) for sound localization<br/>speaker capable of playing WAV or tone sounds
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
| +1 front microphone
|-
|LEDs
|8 red LEDs around the robot, green body light, 1 strong red LED in front
|4 red LEDs and 4 RGB LEDs around the robot, green light, 1 strong red LED in front
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|4x RGB LEDs
|-
|Communication
|RS232 and Bluetooth 2.0 for connection and programming
|USB Full-speed, Bluetooth 2.0, BLE, WiFi
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|WiFi, BLE
|-
|Storage
|Not available
|Micro SD slot
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|Micro SD
|-
|Remote Control
|Infra-red receiver for standard remote control commands
|Same receiver
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Switch / selector
|16 position rotating switch
|Same selector
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Extensions
|Ground sensors, range and bearing, RGB panel, Gumstix extension, omnivision, your own
|All extension supported
|style="text-align:center;" | <img width=40 src="http://www.gctronic.com/doc/images/ok.png">
|
|-
|Programming
|Free C compiler and IDE, Webots simulator, external debugger
|Free C compiler and IDE, Webots simulator, onboard debugger (GDB)
|style="text-align:center;" | <img width=30 src="http://www.gctronic.com/doc/images/plus.png">
|Onboard debugger
|}


This is the overall communication schema:<br/>
When you want to interact with the robot from the computer you need to place the selector in position 3 if you want to work with Bluetooth, or in position 8 if you want to work with USB. Both communication channels use the same protocol called <code>asercom v2</code>, refer to section [http://www.gctronic.com/doc/index.php?title=e-puck2_PC_side_development#Bluetooth_and_USB Communication protocol: BT and USB] for detailed information about this protocol.<br/>
<span class="plainlinks">[http://www.gctronic.com/doc/images/comm-overall-e-puck2E.jpg <img width=700 src="http://www.gctronic.com/doc/images/comm-overall-e-puck2E.jpg">]</span><br/>


==Documentation==
==WiFi==
* '''Main microcontroller''': STM32F407, [http://projects.gctronic.com/epuck2/doc/STM32F407xx_datasheet.pdf datasheet], [http://projects.gctronic.com/epuck2/doc/STM32F407_reference-manual.pdf reference-manual]
For working with the WiFi, the robot must be programmed with a dedicated firmware (not the standard one), refer to section [].
* '''Programmer/debugger''': STM32F413, [http://projects.gctronic.com/epuck2/doc/STM32F413x_datasheet.pdf datasheet], [http://projects.gctronic.com/epuck2/doc/STM32F413_reference-manual.pdf reference-manual]
* '''Radio module''': Espressif ESP32, [http://projects.gctronic.com/epuck2/doc/esp32_datasheet_en.pdf datasheet], [http://projects.gctronic.com/epuck2/doc/esp32_technical_reference_manual_en.pdf reference-manual]
* '''Camera''': PixelPlus PO8030D CMOS image sensor, [http://projects.gctronic.com/E-Puck/docs/Camera/PO8030D.pdf datasheet], no IR cut filter
* '''Microphones''': STM-MP45DT02, [http://projects.gctronic.com/epuck2/doc/mp45dt02.pdf datasheet]
* '''Optical sensors''': Vishay Semiconductors Reflective Optical Sensor, [http://projects.gctronic.com/epuck2/doc/tcrt1000.pdf datasheet]
* '''ToF distance sensor''': STM-VL53L0X, [http://projects.gctronic.com/epuck2/doc/VL53L0X-Datasheet.pdf datasheet], [http://projects.gctronic.com/epuck2/doc/VL53L0X-UserManual-API.pdf user-manual]
* '''IMU''': InvenSense MPU-9250, [http://projects.gctronic.com/epuck2/doc/MPU-9250-product-specification.pdf product-specification], [http://projects.gctronic.com/epuck2/doc/MPU-9250-Register-Map.pdf register-map]
* '''Motors''': [http://www.e-puck.org/index.php?option=com_content&view=article&id=7&Itemid=9 details]
* '''Speaker''': Diameter 13mm, power 500mW, 8 Ohm, DS-1389 or PSR12N08AK or similar
* '''IR receiver''': TSOP36230


==Migrating from e-puck1.x to e-puck2==
=Connecting to the Bluetooth=
The e-puck2 robot maintains full compatibility with its predecessor e-puck, but there are some improvements that you should be aware of.<br/>


First of all the e-jumper, that is the small board that is attached on top of the e-puck1.x, isn't anymore needed in the e-puck2. The components available on the e-jumper are integrated directly in the robot board. On top of the e-puck2 you'll see a quite big free connector, this is used to attach the extensions board designed for the e-puck1.x that are fully compatible with the e-puck2; you must not connect the e-jumper in this connector.<br/>
The default firmware in the ESP32, the module which provides Bluetooth and Wi-Fi connectivity, creates 3 Bluetooth channels using the RFcomm protocol:
# Channel 1, GDB: port to connect with GDB if the programmer is in mode 1 or 3 (refer to chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Configuring_the_Programmer.27s_settings Configuring the Programmer's settings] for more information about these modes)
Secondly you don't need anymore to unplug and plugin the battery for charging, but instead you can charge the battery (up to 1 ampere) directly by connecting the USB cable. If you want you can still charge the battery with the e-puck1.x external charger, in case you have more than one battery.<br/>
# Channel 2, UART: port to connect to the UART port of the main processor
# Channel 3, SPI: port to connect to the SPI port of the main processor (not yet implemented. Just do an echo for now)


Moreover you don't need anymore a special serial cable (with probably an RS232 to USB adapter) to be able to communicate with the robot, but you can use the USB cable. Once connected to the computer a serial port will be available that you can use to easily exchange data with the robot.
By default, the e-puck2 is not visible when you search for it in the Bluetooth utility of your computer.<br>
'''To make it visible, it is necessary to hold the USER button (also labeled "esp32" on the electronic board) while turning on the robot with the ON/OFF button.'''<br>
Then it will be discoverable and you will be able to pair with it.<br>
Note that a prompt could ask you to confirm that the number written on the screen is the same on the e-puck. just ignore this and accept. Otherwise if you are asked for a pin insert 0000.


==Extensions==
==Windows 7==
All the extensions (ground sensors, range and bearing, RGB panel, gumstix and omnvision) are supported by the e-puck2 robot, this means that if you have some extensions for the e-puck1.x you can still use them also with e-puck2.<br/>
When you pair your computer with the e-puck2, 3 COM ports will be automatically created.
For more information about using the gumstix extension with e-puck2 robot refer to [http://www.gctronic.com/doc/index.php?title=Overo_Extension#e-puck2 http://www.gctronic.com/doc/index.php?title=Overo_Extension#e-puck2].
To see which COM port corresponds to which channel you need to open the properties of the paired e-puck2 robot from <code>Bluetooth devices</code>. Then the ports and related channels are listed in the <code>Services</code> tab, as shown in the following figure:<br/>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/BT-connection-win7.png <img width=300 src="http://projects.gctronic.com/epuck2/wiki_images/BT-connection-win7.png">]</span>


=Getting Started=
==Windows 10==
The e-puck2 robot features 3 chips onboard:
When you pair your computer with the e-puck2, 6 COM ports will be automatically created. The three ports you will use have <code>Outgoing</code> direction and are named <code>e_puck2_xxxxx-GDB</code>, <code>e_puck2_xxxxx-UART</code>, <code>e_puck2_xxxxx-SPI</code>. <code>xxxxx</code> is the ID number of your e-puck2.<br/>
* the main microcontroller, that is responsible for handling the sensors and actuators and which runs also the demos/algorithms
To see which COM port corresponds to which channel you need to:
* the programmer, that provides programming/debugging capabilties and moreover it configures the USB hub and is responsible for the power management (on/off of the robot and battery measure)
# open the Bluetooth devices manager
* radio module, that is responsible for handling the wireless communication (WiFi, BLE, BT), the RGB LEDs and the user button (the RGB LEDs and button are connected to the radio module due to the pin number limitation on the main microcontroller)
# pair with the robot
# click on <code>More Bluetooth options</code>
# the ports and related channels are listed in the <code>COM Ports</code> tab, as shown in the following figure:<br/>
:<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/BT-connection-win10.png <img height=300 src="http://projects.gctronic.com/epuck2/wiki_images/BT-connection-win10.png">]</span>


The following sections explain the basic usage of the robot, more detailed information can be found following the links provided.
==Linux==
Once paired with the Bluetooth manager, you need to create the port for communicating with the robot by issueing the command: <br/>
<code>sudo rfcomm bind /dev/rfcomm0 MAC_ADDR 2</code><br/>
The MAC address is visible from the Bluetooth manager. The parameter <code>2</code> indicates the channel, in this case a port for the <code>UART</code> channel is created. If you want to connect to another service you need to change this parameter accordingly (e.g. <code>1</code> for <code>GDB</code> and <code>3</code> for <code>SPI</code>). Now you can use <code>/dev/rfcomm0</code> to connect to the robot.


==Turn on/off the robot==
==Mac==
To turn on the robot you need to press the power button (blue button) placed on the bottom side of the board, near the speaker, as shown in the following figures:
When you pair your computer with the e-puck2, 3 COM ports will be automatically created: <code>/dev/cu.e-puck2_xxxxx-GDB</code>, <code>/dev/cu.e-puck2_xxxxx-UART</code> and <code>/dev/cu.e-puck2_xxxxx-SPI</code>. xxxxx is the ID number of your e-puck2.
::<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/e-puck2-btn-on-off2.jpg <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2-btn-on-off2-small.jpg">][http://projects.gctronic.com/epuck2/wiki_images/e-puck2-btn-on-off.jpg <img width=300 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2-btn-on-off-small.jpg">]</span><br/>
To turn off the robot you need to press the power button for 1 second.


==Meaning of the LEDs==
=Connecting to the WiFi=
The e-puck2 has three groups of LEDs that are not controllable by the user.
At the moment the WiFi channel is used to transfer the image to the computer (a QQVGA color image is transferred) together with the sensors values (magnetometer, selector and tv remote not supported at the moment). The robot is also able to receive commands from the computer (only motors and red LEDs are supported at the moment).<br/>
A dedicated configuration is needed to use the WiFi, thus the robot and WiFi module firmwares need to be updated; moreover a PC application is provided to receive the data from the robot and send commands to it:
# [http://projects.gctronic.com/epuck2/e-puck2_main-processor_wifi_afaa618.elf main processor firmware] (see chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Flashing_the_main_microcontroller Flashing the main microcontroller]to update the firmware); put the selector in position 15. If you are interested to the source code, refer to chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#WiFi_support_2 Main microcontroller - WiFi support].
# [http://projects.gctronic.com/epuck2/esp32-firmware-wifi-7bf44de.zip WiFi module firmware] (see chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Flashing_the_radio_module Flashing the radio module] to update the firmware). If you are interested to the source code, refer to chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#WiFi_support_3 Radio module - WiFi support].
# PC application: [http://projects.gctronic.com/epuck2/monitor_wifi_27dddd4.zip Monitor WiFi]. If you are interested to the source code, refer to chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#WiFi_support PC interface - WiFi support].


::<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/e-puck2_top_leds.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2_top_leds.png">]</span><br/>
The LED2 is used to indicate the state of the WiFi connection:
::''Top view of the e-puck2''
* red indicates that the robot is in ''access point mode'' (waiting for configuration)
* green indicates that the robot is connected to a network and has received an IP address
* blue (toggling) indicates that the robot is transferring the image to the computer


*Charger: RED if charging, GREEN if charge complete and RED and GREEN if an error occurs
==Network configuration==
*USB: Turned ON if the e-puck2 detects a USB connection with a computer
If there is no WiFi configuration saved in flash, then the robot will be in ''access point mode'' in order to let the user connect to it and setup a WiFi connection. The LED2 is red.  
*STATUS: Turned ON if the robot is ON and OFF if the robot is OFF. When ON, gives an indication of the level of the battery. Also blinks GREEN if the program is running during a debug session.


Battery level indications (STATUS RGB LED):
The access point SSID will be <code>e-puck2_0XXXX</code> where <code>XXXX</code> is the id of the robot; the password to connect to the access point is <code>e-puck2robot</code>.<br/>
*GREEN if the system's tension is greater than 3.5V
You can use a phone, a tablet or a computer to connect to the robot's WiFi and then you need to open a browser and insert the address <code>192.168.1.1</code>. The available networks are scanned automatically and listed in the browser page as shown in ''figure 1''. Choose the WiFi signal you want the robot to establish a conection with from the web generated list, and enter the related password; if the password is correct you'll get a message saying that the connection is established as shown in ''figure 2''. After pressing <code>OK</code> you will be redirected to the main page showing the network to which you're connected and the others available nearby as shown in ''figure 3''. If you press on the connected network, then you can see your IP address as shown in ''figure 4''; take note of the address since it will be needed later.<br/>
*ORANGE if the system's tension is between 3.5V and 3.4V
*RED if the system's tension is between 3.4V and 3.3V
*RED blinking if the system's tension is below 3.3V


The robot is automatically turned OFF if the system's tension gets below 3.2V during 10 seconds.
<span class="plainlinks">
<table>
<tr>
<td align="center">[1]</td>
<td align="center">[2]</td>
<td align="center">[3]</td>
<td align="center">[4]</td>
</tr>
<tr>
<td>[http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup1.png <img width=150 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup1.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup2.png <img width=150 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup2.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup3.png <img width=150 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup3.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup4.png <img width=150 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup4.png">]</td>
</tr>
</table>
</span><br/>
Now the configuration is saved in flash, this means that when the robot is turned on it will read this configuration and try to establish a connection automatically.<br/>
Remember that you need to power cycle the robot at least once for the new configuration to be active.<br/>


==Connecting the USB cable==
Once the connection is established, the LED2 will be green.<br/>
A micro USB cable (included with the robot in the package) is needed to connect the robot to the computer. There are two connectors, one placed on top of the robot facing upwards and the other placed on the side of the robot, as shown in the following figures. Both can be used to charge the robot (up to 1 ampere) or to communicate with it, but do not connect two cables at the same time. Connect the USB cable where is more comfortable to you.
::<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/e-puck2-usb-conn.jpg <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2-usb-conn-small.jpg">][http://projects.gctronic.com/epuck2/wiki_images/e-puck2-usb-conn2.jpg <img width=300 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2-usb-conn2-small.jpg">]</span><br/>


==Installing the USB drivers==
In order to reset the current configuration you need to press the user button for 2 seconds (the LED2 red will turn on), then you need to power cycle the robot to enter ''access point mode''.
The USB drivers must be installed only for the users of a Windows version older than Windows 10:


#Download and open [http://projects.gctronic.com/epuck2/zadig-2.3.exe zadig-2.3.exe]
==Receiving the image==
#Connect the e-puck2 with the USB cable and turn it on. Three unknown devices appear in the device list of the program, namely '''e-puck2 STM32F407''', '''e-puck2 GDB Server (Interface 0)''' and '''e-puck2 Serial Monitor (Interface 2)'''.
Run the pc application and insert the IP address of the robot. Click on <code>Connect</code> to start receiving the image. The LED2 blue will toggle.<br/>
#For each of the three devices mentioned above, select the <code>USB Serial (CDC)</code> driver and click on the <code>Install Driver</code> button to install it. Accept the different prompts which may appear during the process. At the end you can simply quit the program and the drivers are installed. These steps are illustrated on Figure 3 below.
::Note : The drivers installed are located in <code>C:\Users\"your_user_name"\usb_driver</code>


:<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/Zadig_e-puck2_STM32F407.png <img width=500 src="http://projects.gctronic.com/epuck2/wiki_images/Zadig_e-puck2_STM32F407.png">]</span><br/>
Often the IP address assigned to the robot will remain the same when connecting to the same network, so if you took note of the IP address in section [http://www.gctronic.com/doc/index.php?title=e-puck2#Network_configuration Network configuration] probably you're ready to go. <br/>
::''Example of driver installation for e-puck2 STM32F407''
Otherwise you need to connect the robot to the computer with the USB cable and open the port labeled <code>Serial Monitor</code> (see chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Finding_the_USB_serial_ports_used Finding the USB serial ports used]). Then power cycle the robot and the IP address will be shown in the terminal (together with others informations), as illustrated in the following figure:<br/>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup5.png <img width=500 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-wifi-setup5.png">]</span>


The drivers are automatically installed with Windows 10, Linux and Mac OS.
=Configuring the PATH variable=
The PATH variable is a environment variable used to store a list of the paths to the folders containing the executables we can run in a terminal with Windows, Mac and Linux.


Anyway in Linux in order to access the serial ports, a little configuration is needed. Type the following command in a terminal session: <code>sudo adduser $USER dialout</code>. Once done, you need to log off to let the change take effect.
If you want to use the arm-none-eabi toolchain provided inside the Eclipse_e-puck2 package, you have to add it to the PATH variable to be able to call it inside a terminal window.


==Finding the USB serial ports used==
Setting the PATH variable for Windows :
Two ports are created by the e-puck2's programmer when the USB cable is connected to the robot (even if the robot is turned off):
<pre>set PATH=your_installation_path\Eclipse_e-puck2\Tools\gcc-arm-none-eabi-7-2017-q4-major-win32\bin;%PATH%</pre>
* '''e-puck2 GDB Server'''. The port used to program and debug the e-puck2.
Setting the PATH variable for Linux :
* '''e-puck2 Serial Monitor'''. Serial communication between the PC and the radio module (used also to program the radio module).
<pre>export PATH=your_installation_path/Eclipse_e-puck2/Tools/gcc-arm-none-eabi-7-2017-q4-major/bin:$PATH</pre>
Setting the PATH variable for Mac :
<pre>export PATH=your_installation_path/Eclipse_e-puck2.app/Contents/Eclipse_e-puck2/Tools/gcc-arm-none-eabi-7-2017-q4-major/bin:$PATH</pre>


A third port could be available depending on the code inside the e-puck2's microcontroller. With the standard firmware a port named '''e-puck2 STM32F407''' is created.
What is important to know is that this procedure is temporary. It applies only to the terminal window used to type it. If you open a new terminal window or close this one, you will have to set again the PATH variable.
===Windows===
#Open the Device Manager
#Under '''Ports (COM & LPT)''' you can see the virtual ports connected to your computer.
#Do a '''Right-click -> properties''' on the COM port you want to identify.
#Go under the '''details''' tab and select '''Bus reported device description''' in the properties list.
#The name of the port should be written in the text box below.
#Once you found the desired device, you can simply look at its port number '''(COMX)'''.


===Linux===
Note : The arm-none-eabi version can differ from the one given in this example. It could be needed to adapt the path to the correct version.
:1. Open a terminal window (<code>ctrl+alt+t</code>) and enter the following command: <code>ls /dev/ttyACM*</code>
:2. Look for '''ttyACM0''' and '''ttyACM1''' in the generated list, which are respectively '''e-puck2 GDB Server''' and '''e-puck2 Serial Monitor'''. '''ttyACM2''' will be also available with the standard firmware, that is related to '''e-puck2 STM32F407''' port
Note : Virtual serial port numbering on Linux depends on the connections order, thus it can be different if another device using virtual serial ports is already connected to your computer before connecting the robot.


===Mac===
:1. Open a terminal window and enter the following command: <code>ls /dev/cu.usbmodem*</code>
:2. Look for two '''cu.usbmodemXXXX''', where XXXX is the number attributed by your computer. You should find two names, with a numbering near to each other, which are respectively '''e-puck2 GDB Server''' and '''e-puck2 Serial Monitor'''. A third device '''cu.usbmodemXXXX''' will be available with the standard firmware, that is related to '''e-puck2 STM32F407''' port


Note : Virtual serial port numbering on Mac depends on the physical USB port used and the device. If you want to keep the same names, you must connect to the same USB port each time.
=Communication protocol=
This section is the hardest part to understand. It outlines all the details about the communication protocols that you'll need to implement in order to communicate with the robot form the computer. So spend a bit of time reading and re-reading this section in order to grasp completely all the details.


==PC interface==
==Bluetooth and USB==
<span class="plainlinks">[http://projects.gctronic.com/epuck2/wiki_images/monitor.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/monitor_small.png">]<br/>
A PC application was developed to start playing with the robot: you can have information about all the sensors, receive camera images and control the leds and motors.<br/>
With the standard firmware programmed in the robot, place the selector in position 8, attach the USB cable and turn on the robot. Enter the correct port (the one related to <code>e-puck2 STM32F407</code>) in the interface and click <code>connect</code>.


The source code is available from the repository [https://github.com/e-puck2/monitor https://github.com/e-puck2/monitor].<br/>


Available executables:
==WiFi==
* [http://projects.gctronic.com/epuck2/monitor_win.zip Windows executable]: tested on Windows 7 and Windows 10
The communication is based on TCP; the robot create a TCP server and wait for a connection.<br/>
* [http://projects.gctronic.com/epuck2/monitor_mac.zip Max OS X executable]


On Linux remember to apply the configuration explained in the chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Installing_the_USB_drivers Installing the USB drivers] in order to access the serial port.
Each packet is identified by an ID (1 byte). The following IDs are used to send data from the robot to the computer:
* 0x00 = reserved
* 0x01 = QQVGA color image packet (only the first segment includes this id); packet size (without id) = 38400 bytes; image format = RGB565
* 0x02 = sensors packet; packet size (without id) = 104 bytes; the format of the returned values are based on the [http://www.gctronic.com/doc/index.php/Advanced_sercom_protocol asercom protocol] and are compatible with e-puck1.x:


==PC side development==
:<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/packet-format-robot-to-pc.jpg <img width=1150 src="http://projects.gctronic.com/epuck2/wiki_images/packet-format-robot-to-pc.jpg">]</span><br/>
This section is dedicated to the users that develop algorithms on the PC side and interact with the robot remotely through a predefined communication protocol. These users don't modify the firmware of the robot, but instead they use the standard firmware released with the robot. They update the robot firmware only when there is an official update. <br/>
:*Acc: raw axes values, between -1500 and 1500, resolution is +-2g
The remote control of the robot, by receiving sensors values and setting the actuators, is done through the following channels: Bluetooth, Bluetooth Low Energy, WiFi, USB cable.<br/>
:*Acceleration: acceleration magnitude <img width=70 src="http://projects.gctronic.com/epuck2/wiki_images/3dvector-magnitude.png">, between 0.0 and about 2600.0 (~3.46 g)
Examples of tools/environment used by these users:
:*Orientation: between 0.0 and 360.0 degrees <table><tr><td align="center">0.0 deg</td><td align="center">90.0 deg</td><td align="center">180 deg</td><td align="center">270 deg</td></tr><tr><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/orientation0.png"></td><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/orientation90.png"></td><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/orientation180.png"></td><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/orientation270.png"></td></tr></table>
# Aseba
# Simulator (e.g. Webots)
# ROS
# iOS, Android apps
# Custom PC application
# IoT (e.g. IFTTT)
If you fall into this category, then follow this section for more information: [http://www.gctronic.com/doc/index.php?title=e-puck2_PC_side_development PC side development].<br/>


=Main microcontroller=
:*Inclination: between 0.0 and 90.0 degrees (when tilted in any direction)<table><tr><td align="center">0.0 deg</td><td align="center">90.0 deg</td></tr><tr><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/inclination0.png"></td><td><img width=80 src="http://projects.gctronic.com/epuck2/wiki_images/inclination90.png"></td></tr></table>
The e-puck2 robot main microcontroller is a 32-bit STM32F407 that runs at 168 MHz (210 DMIPS) and include DSP, FPU and DMA capabilities. The version chosen for the e-puck2 has 192 KB of total RAM and 1024 KB of flash, so there is a lot of memory to work with.<br/>
:*Gyro: raw axes values, between -32768 and 32767, range is +-250dps
This chip is responsible for handling the sensors and actuators and runs also the demos and algorithms.
:*Magnetometer: raw axes values, between -32760 and 32760, range is +-4912 uT (magnetic flux density expressed in micro Tesla)
:*Temp: temperature given in Celsius degrees
:*IR proximity: between 0 (no objects detected) and 4095 (object near the sensor)
:*IR ambient: between 0 (strong light) and 4095 (dark)
:*ToF distance: distance given in millimeters
:*Mic volume: between 0 and 4095
:*Motors steps: 1000 steps per wheel revolution
:*Battery:
:*uSD state: 1 if the micro sd is present and can be read/write, 0 otherwise
:*TV remote data: RC5 protocol
:*Selector position: between 0 and 15
:*Ground proximity: between 0 (no surface at all or not reflective surface e.g. black) and 1023 (very reflective surface e.g. white)
:*Ground ambient: between 0 (strong light) and 1023 (dark)
:*Button state: 1 button pressed, 0 button released
* 0x03 = empty packet (only id is sent); this is used as an acknowledgment for the commands packet when no sensors and no image is requested
The following IDs are used to send data from the computer to the robot:
* 0x80 = commands packet; packet size (without id) = 20 bytes:


==Standard firmware==
:<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/packet-format-pc-to-robot.jpg <img width=600 src="http://projects.gctronic.com/epuck2/wiki_images/packet-format-pc-to-robot.jpg">]</span><br/>
The main microcontroller of the robot is initially programmed with a firmware that includes many demos that could be started based on the selector position, here is a list of the demos with related position and a small description:
* Selector position 0: Aseba
* Selector position 1: Shell
* Selector position 2: Read proximity sensors
* Selector position 3: Asercom protocol v2 (BT)
* Selector positoin 4: Range and bearing extension (receiver)
* Selector position 5: Range and bearing extension (transmitter)
* Selector position 6: ESP32 UART communication test
* Selector position 7: ...
* Selector position 8: Asercom protocol v2 (USB)
* Selector position 9: Asercom protocol (BT)
* Selector position 10: This position is used to work with the gumstix extension.
* Selector position 11: Simple obstacle avoidance + some animation
* Selector position 12: Hardware test
* Selector position 13: LEDs reflect orientation of the robot
* Selector position 14: Read magnetometer sensor
* Selector position 15: ...
The pre-built firmware is available here [http://projects.gctronic.com/epuck2/e-puck2_main-processor_23.04.18_3988f7c.elf robot standard firmware].


==Firmware update==
:*request:
Now and then there could be an official firmware update for the robot and it's important to keep the robot updated with the last firmware to get possibile new features, improvements and for bug fixes.<br/>
:** bit0: 0=stop image stream; 1=start image stream
The onboard programmer run a GDB server, so we use GDB commands to upload a new firmware, for this reason a toolchain is needed to upload a new firmware to the robot.<br/>
:** bit1: 0=stop sensors stream; 1=start sensors stream
The following steps explain how to update the robot firmware:<br/>
:*settings:
1. Download the package containing the required toolchain and script to program the robot: [http://projects.gctronic.com/epuck2/e-puck2-pc-dev-windows.zip Windows], [Linux], [Mac OS]<br/>
:** bit0: 1=calibrate IR proximity sensors
2. Download the last version of the [http://projects.gctronic.com/epuck2/e-puck2_main-processor_23.04.18_3988f7c.elf robot standard firmware], or use your custom firmware<br/>
:** bit1: 0=disable onboard obstacle avoidance; 1=enable onboard obstacle avoidance (not implemented yet)
3. Extract the package and put the firmware file (with <code>elf</code> extension) inside the package directory; beware that only one <code>elf</code> file must be present inside this directory<br/>
:** bit2: 0=set motors speed; 1=set motors steps (position)
4. Attach the USB cable and turn on the robot<br/>
:*left and right: when bit2 of <code>settings</code> field is <code>0</code>, then this is the desired motors speed (-1000..1000); when <code>1</code> then this is the value that will be set as motors position (steps)
5. Run the script:<br/>
:*LEDs: 0=off; 1=on; 2=toggle
:Windows: double click <code>program.bat</code><br/>
:** bit0: 0=LED1 off; 1=LED1 on
:Linux:<br/>
:** bit1: 0=LED3 off; 1=LED3 on
:Mac OS:<br/>
:** bit2: 0=LED5 off; 1=LED5 on
:** bit3: 0=LED7 off; 1=LED7 on
:** bit4: 0=body LED off; 1=body LED on
:** bit5: 0=front LED off; 1=front LED on
:*RGB LEDs: for each LED, it is specified in sequence the value of red, green and blue (0...100)
:* sound id: 0x01=MARIO, 0x02=UNDERWOLRD, 0x04=STARWARS, 0x08=4KHz, 0x10=10KHz, 0x20=stop sound


==Robot side development==
For example to receive the camera image (stream) the following steps need to be followed:<br/>
If you are an embedded developer and are brave enough, then you have complete access to the source code running on the robot, so you can discover what happen inside the main microcontroller and modify it to accomodate your needs. Normally the users that fall into this category develop algorithms optimized to run directly on the microcontroller, such as:
1) connect to the robot through TCP<br/>
# onboard image processing
2) send the command packet:  
# swarm algorithms
:{| border="1"
# fully autonomous behaviors
|0x80
# ...
|0x01
For more information about programming the robot itself, refer to section [http://www.gctronic.com/doc/index.php?title=e-puck2_robot_side_development Robot side development]
|0x00
 
|0x00
=Radio module=
|0x00
The radio module chosen for the e-puck is the new ESP32 chip from [https://www.espressif.com/ Espressif], integrating a dual core that run up to 240 MHz, 4 MB of flash and 520 KB of RAM. It supports WiFi standards 802.11 b/g/n (access point mode supported), Bluetooth and Bluetooth LE 4.2. It is the successor of the ESP8266 chip. The following figure shows the various peripherals available on the ESP32:<br/>
|0x00
<span class="plain links"><img width=400 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-peripherals.png"></span>
|0x00
 
|0x00
This chip first of all is responsible for handling the wireless communication, moreover it handles also the RGB LEDs (with PWM) and the user button. The RGB LEDs and button are connected to the radio module due to the pin number limitation on the main microcontroller.
|0x00
 
|0x00
==Standard firmware==
|0x00
The radio module of the robot is initially programmed with a firmware that supports Bluetooth communication.<br/>
|0x00
The pre-built firmware is available here [http://projects.gctronic.com/epuck2/esp32-firmware_26.01.18_37db240.zip esp32-firmware.zip].
|0x00
 
|0x00
==Firmware update==
|0x00
In order to update the firmware of the ESP32 WiFi module you need to use a python script called <code>esptool</code> provided by Espressif (manufacturer of the chip). This script was modified to work with the e-puck2 robot and is available from the following link:
|0x00
* Windows: [http://projects.gctronic.com/epuck2/esptool.exe esptool.exe]; Python not required on the system.
|0x00
* Linux/Mac: [http://projects.gctronic.com/epuck2/esptool.py esptool.py]; Python 3.4 and pySerial 2.5 need to be installed on the system.
|0x00
Place the script in the same folder as the firmware (composed by 3 bin files: <code>bootloader.bin</code>, <code>ESP32_E-Puck_2.bin</code> and <code>partitions_singleapp.bin</code>) and then issue the following command:
|0x00
* Windows:
|0x00
<pre>esptool.exe --chip esp32 --port COM96 --baud 230400 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader.bin 0x10000 ESP32_E-Puck_2.bin 0x8000 partitions_singleapp.bin</pre>
|0x00
Alternatively you can download the following batch file [http://projects.gctronic.com/epuck2/esp32-flashing.bat esp32-flashing.bat]
|}
*Linux/Mac:
3) read the ID (1 byte) and the QQVGA color image pakcet (38400 bytes)<br/>
<pre>python esptool.py --chip esp32 --port COM96 --baud 230400 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader.bin 0x10000 ESP32_E-Puck_2.bin 0x8000 partitions_singleapp.bin</pre>
4) go to step 3
In all cases you need to specify the correct port (with <code>--port</code> parameter) that is the one labeled <code>Serial monitor</code> (see chapter [http://www.gctronic.com/doc/index.php?title=e-puck2#Finding_the_USB_serial_ports_used Finding the USB serial ports used]).
 
The upload should last about 10-15 seconds and you'll see the progress as shown in the following figure:<br/>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing1.png <img width=400 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing1.png">]</span><br/>
When the upload is complete you'll see that all 3 bin files are uploaded correctly as shown in the following figure:<br/>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing2.png <img width=400 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing2.png">]</span><br/>
 
Sometime you could encounter a timeout error as shown in the following figures; in these cases you need to unplug and plug again the USB cable and power cycle the robot, then you can retry.<br/>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing3.png <img width=400 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing3.png">]</span>
<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing4.png <img width=400 src="http://projects.gctronic.com/epuck2/wiki_images/esp32-flashing4.png">]</span><br/>
 
==Development==
Probably, you'll never need to touch the firmware running in the radio module, but in case you need to modify the code or you're simply curious about what is happening at the low level, then refer to the section [http://www.gctronic.com/doc/index.php?title=e-puck2_radio_module_development Radio module development].
 
=Programmer=
 
==Standard firmware==
The programmer is initially programmed with a firmware based on [https://github.com/blacksphere/blackmagic/wiki Black Magic Probe programmer/debugger].<br/>
The pre-built firmware is available here [http://projects.gctronic.com/epuck2/programmer-firmware_09.04.18_252d604.bin programmer-firmware.bin]; it is also available in dfu format here [http://projects.gctronic.com/epuck2/programmer-firmware_09.04.18_252d604.dfu programmer-firmware.dfu].
 
==Firmware update==
The programmer's microcontroller features a factory bootloader that can be entered by acting on some special pins, the bootloader mode is called DFU (device firmware upgrade). You can enter DFU mode by contacting two pinholes together while inserting the USB cable (no need to turn on the robot). The two pin holes are located near the USB connector of the e-puck2, see the photo below.
 
::<span class="plain links">[http://projects.gctronic.com/epuck2/wiki_images/e-puck2_top_leds_DFU_413.png <img width=200 src="http://projects.gctronic.com/epuck2/wiki_images/e-puck2_top_leds_DFU_413.png">]</span><br/>
::''Location of the pin holes to put the programmer into DFU''
 
The programmer will be recognized as <code>STM Device in DFU Mode</code> device.


'''Note for Windows users''': the device should be recognized automatically (in all Windows versions), but in case it won't be detected then you need to install a <code>libusbK</code> driver for the DFU device.<br>
=Webots=
Follow the same procedure as explained in section [http://www.gctronic.com/doc/index.php?title=e-puck2#Installing_the_USB_drivers Installing the USB drivers] using <code>libusbK</code> driver instead of <code>USB Serial (CDC)</code>.
TBD
 
===Linux===
In order to update the programmer firmware you need an utility called <code>dfu-util</code>.<br/>
To install it, issue the command <code>sudo apt-get install dfu-util</code>.<br/>
Then issue the following command to upload the firmware: <code>sudo dfu-util -d 0483:df11 -a 0 -s 0x08000000 -D programmer-firmware.bin</code>
 
===Windows===
For Windows users it is available an application called <code>DfuSe</code> released by STMicroelectronics. You can download it from [http://projects.gctronic.com/epuck2/en.stsw-stm32080_DfuSe_Demo_V3.0.5.zip DfuSe_V3.0.5.zip].<br/>
When the program is started, the programmer in DFU mode will be automatically detected as shown in figure 1. Then you need to open the compiled firmware by clicking on <code>choose</code> and then locating the file with <code>dfu</code> extension,  as shown in figure 2. Now click on the <code>upgrade</code> button, a warning message will be shown, confirm the action by clicking on <code>yes</code> as shown in figure 3. If all is ok you'll be prompted with a message saying that the upgrade was successfull as shown in figure 4.<br/>
<span class="plainlinks">
<table>
<tr>
<td align="center">[1]</td>
<td align="center">[2]</td>
<td align="center">[3]</td>
<td align="center">[4]</td>
</tr>
<tr>
<td>[http://projects.gctronic.com/epuck2/wiki_images/dfu1.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/dfu1.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/dfu2.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/dfu2.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/dfu3.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/dfu3.png">]</td>
<td>[http://projects.gctronic.com/epuck2/wiki_images/dfu4.png <img width=250 src="http://projects.gctronic.com/epuck2/wiki_images/dfu4.png">]</td>
</tr>
</table>
</span><br/>


==Development==
=ROS=
[http://www.gctronic.com/doc/index.php?title=e-puck2_programmer_development Programmer development]
TBD

Revision as of 09:09, 31 July 2018

e-puck2 main wiki

Robot configuration

This section explains how to configure the robot based on the communication channel you will use for your developments, thus you need to read only one of the following sections, but it would be better if you spend a bit of time reading them all in order to have a full understanding of the available configurations.

Bluetooth and USB

The main microcontroller and radio module of the robot are initially programmed with firmwares that together support Bluetooth and USB communication.

If the main microcontroller and radio module aren't programmed with the standard firmware or if you want to be sure to have the last firmwares on the robot, you need to program them with the last standard firmware:

  • for the main microcontroller, refer to section Firmware update.
  • for the radio module, refer to section []

When you want to interact with the robot from the computer you need to place the selector in position 3 if you want to work with Bluetooth, or in position 8 if you want to work with USB. Both communication channels use the same protocol called asercom v2, refer to section Communication protocol: BT and USB for detailed information about this protocol.

WiFi

For working with the WiFi, the robot must be programmed with a dedicated firmware (not the standard one), refer to section [].

Connecting to the Bluetooth

The default firmware in the ESP32, the module which provides Bluetooth and Wi-Fi connectivity, creates 3 Bluetooth channels using the RFcomm protocol:

  1. Channel 1, GDB: port to connect with GDB if the programmer is in mode 1 or 3 (refer to chapter Configuring the Programmer's settings for more information about these modes)
  2. Channel 2, UART: port to connect to the UART port of the main processor
  3. Channel 3, SPI: port to connect to the SPI port of the main processor (not yet implemented. Just do an echo for now)

By default, the e-puck2 is not visible when you search for it in the Bluetooth utility of your computer.
To make it visible, it is necessary to hold the USER button (also labeled "esp32" on the electronic board) while turning on the robot with the ON/OFF button.
Then it will be discoverable and you will be able to pair with it.
Note that a prompt could ask you to confirm that the number written on the screen is the same on the e-puck. just ignore this and accept. Otherwise if you are asked for a pin insert 0000.

Windows 7

When you pair your computer with the e-puck2, 3 COM ports will be automatically created. To see which COM port corresponds to which channel you need to open the properties of the paired e-puck2 robot from Bluetooth devices. Then the ports and related channels are listed in the Services tab, as shown in the following figure:

Windows 10

When you pair your computer with the e-puck2, 6 COM ports will be automatically created. The three ports you will use have Outgoing direction and are named e_puck2_xxxxx-GDB, e_puck2_xxxxx-UART, e_puck2_xxxxx-SPI. xxxxx is the ID number of your e-puck2.
To see which COM port corresponds to which channel you need to:

  1. open the Bluetooth devices manager
  2. pair with the robot
  3. click on More Bluetooth options
  4. the ports and related channels are listed in the COM Ports tab, as shown in the following figure:

Linux

Once paired with the Bluetooth manager, you need to create the port for communicating with the robot by issueing the command:
sudo rfcomm bind /dev/rfcomm0 MAC_ADDR 2
The MAC address is visible from the Bluetooth manager. The parameter 2 indicates the channel, in this case a port for the UART channel is created. If you want to connect to another service you need to change this parameter accordingly (e.g. 1 for GDB and 3 for SPI). Now you can use /dev/rfcomm0 to connect to the robot.

Mac

When you pair your computer with the e-puck2, 3 COM ports will be automatically created: /dev/cu.e-puck2_xxxxx-GDB, /dev/cu.e-puck2_xxxxx-UART and /dev/cu.e-puck2_xxxxx-SPI. xxxxx is the ID number of your e-puck2.

Connecting to the WiFi

At the moment the WiFi channel is used to transfer the image to the computer (a QQVGA color image is transferred) together with the sensors values (magnetometer, selector and tv remote not supported at the moment). The robot is also able to receive commands from the computer (only motors and red LEDs are supported at the moment).
A dedicated configuration is needed to use the WiFi, thus the robot and WiFi module firmwares need to be updated; moreover a PC application is provided to receive the data from the robot and send commands to it:

  1. main processor firmware (see chapter Flashing the main microcontrollerto update the firmware); put the selector in position 15. If you are interested to the source code, refer to chapter Main microcontroller - WiFi support.
  2. WiFi module firmware (see chapter Flashing the radio module to update the firmware). If you are interested to the source code, refer to chapter Radio module - WiFi support.
  3. PC application: Monitor WiFi. If you are interested to the source code, refer to chapter PC interface - WiFi support.

The LED2 is used to indicate the state of the WiFi connection:

  • red indicates that the robot is in access point mode (waiting for configuration)
  • green indicates that the robot is connected to a network and has received an IP address
  • blue (toggling) indicates that the robot is transferring the image to the computer

Network configuration

If there is no WiFi configuration saved in flash, then the robot will be in access point mode in order to let the user connect to it and setup a WiFi connection. The LED2 is red.

The access point SSID will be e-puck2_0XXXX where XXXX is the id of the robot; the password to connect to the access point is e-puck2robot.
You can use a phone, a tablet or a computer to connect to the robot's WiFi and then you need to open a browser and insert the address 192.168.1.1. The available networks are scanned automatically and listed in the browser page as shown in figure 1. Choose the WiFi signal you want the robot to establish a conection with from the web generated list, and enter the related password; if the password is correct you'll get a message saying that the connection is established as shown in figure 2. After pressing OK you will be redirected to the main page showing the network to which you're connected and the others available nearby as shown in figure 3. If you press on the connected network, then you can see your IP address as shown in figure 4; take note of the address since it will be needed later.

[1] [2] [3] [4]


Now the configuration is saved in flash, this means that when the robot is turned on it will read this configuration and try to establish a connection automatically.
Remember that you need to power cycle the robot at least once for the new configuration to be active.

Once the connection is established, the LED2 will be green.

In order to reset the current configuration you need to press the user button for 2 seconds (the LED2 red will turn on), then you need to power cycle the robot to enter access point mode.

Receiving the image

Run the pc application and insert the IP address of the robot. Click on Connect to start receiving the image. The LED2 blue will toggle.

Often the IP address assigned to the robot will remain the same when connecting to the same network, so if you took note of the IP address in section Network configuration probably you're ready to go.
Otherwise you need to connect the robot to the computer with the USB cable and open the port labeled Serial Monitor (see chapter Finding the USB serial ports used). Then power cycle the robot and the IP address will be shown in the terminal (together with others informations), as illustrated in the following figure:

Configuring the PATH variable

The PATH variable is a environment variable used to store a list of the paths to the folders containing the executables we can run in a terminal with Windows, Mac and Linux.

If you want to use the arm-none-eabi toolchain provided inside the Eclipse_e-puck2 package, you have to add it to the PATH variable to be able to call it inside a terminal window.

Setting the PATH variable for Windows :

set PATH=your_installation_path\Eclipse_e-puck2\Tools\gcc-arm-none-eabi-7-2017-q4-major-win32\bin;%PATH%

Setting the PATH variable for Linux :

export PATH=your_installation_path/Eclipse_e-puck2/Tools/gcc-arm-none-eabi-7-2017-q4-major/bin:$PATH

Setting the PATH variable for Mac :

export PATH=your_installation_path/Eclipse_e-puck2.app/Contents/Eclipse_e-puck2/Tools/gcc-arm-none-eabi-7-2017-q4-major/bin:$PATH

What is important to know is that this procedure is temporary. It applies only to the terminal window used to type it. If you open a new terminal window or close this one, you will have to set again the PATH variable.

Note : The arm-none-eabi version can differ from the one given in this example. It could be needed to adapt the path to the correct version.


Communication protocol

This section is the hardest part to understand. It outlines all the details about the communication protocols that you'll need to implement in order to communicate with the robot form the computer. So spend a bit of time reading and re-reading this section in order to grasp completely all the details.

Bluetooth and USB

WiFi

The communication is based on TCP; the robot create a TCP server and wait for a connection.

Each packet is identified by an ID (1 byte). The following IDs are used to send data from the robot to the computer:

  • 0x00 = reserved
  • 0x01 = QQVGA color image packet (only the first segment includes this id); packet size (without id) = 38400 bytes; image format = RGB565
  • 0x02 = sensors packet; packet size (without id) = 104 bytes; the format of the returned values are based on the asercom protocol and are compatible with e-puck1.x:

  • Acc: raw axes values, between -1500 and 1500, resolution is +-2g
  • Acceleration: acceleration magnitude , between 0.0 and about 2600.0 (~3.46 g)
  • Orientation: between 0.0 and 360.0 degrees
    0.0 deg90.0 deg180 deg270 deg
  • Inclination: between 0.0 and 90.0 degrees (when tilted in any direction)
    0.0 deg90.0 deg
  • Gyro: raw axes values, between -32768 and 32767, range is +-250dps
  • Magnetometer: raw axes values, between -32760 and 32760, range is +-4912 uT (magnetic flux density expressed in micro Tesla)
  • Temp: temperature given in Celsius degrees
  • IR proximity: between 0 (no objects detected) and 4095 (object near the sensor)
  • IR ambient: between 0 (strong light) and 4095 (dark)
  • ToF distance: distance given in millimeters
  • Mic volume: between 0 and 4095
  • Motors steps: 1000 steps per wheel revolution
  • Battery:
  • uSD state: 1 if the micro sd is present and can be read/write, 0 otherwise
  • TV remote data: RC5 protocol
  • Selector position: between 0 and 15
  • Ground proximity: between 0 (no surface at all or not reflective surface e.g. black) and 1023 (very reflective surface e.g. white)
  • Ground ambient: between 0 (strong light) and 1023 (dark)
  • Button state: 1 button pressed, 0 button released
  • 0x03 = empty packet (only id is sent); this is used as an acknowledgment for the commands packet when no sensors and no image is requested

The following IDs are used to send data from the computer to the robot:

  • 0x80 = commands packet; packet size (without id) = 20 bytes:

  • request:
    • bit0: 0=stop image stream; 1=start image stream
    • bit1: 0=stop sensors stream; 1=start sensors stream
  • settings:
    • bit0: 1=calibrate IR proximity sensors
    • bit1: 0=disable onboard obstacle avoidance; 1=enable onboard obstacle avoidance (not implemented yet)
    • bit2: 0=set motors speed; 1=set motors steps (position)
  • left and right: when bit2 of settings field is 0, then this is the desired motors speed (-1000..1000); when 1 then this is the value that will be set as motors position (steps)
  • LEDs: 0=off; 1=on; 2=toggle
    • bit0: 0=LED1 off; 1=LED1 on
    • bit1: 0=LED3 off; 1=LED3 on
    • bit2: 0=LED5 off; 1=LED5 on
    • bit3: 0=LED7 off; 1=LED7 on
    • bit4: 0=body LED off; 1=body LED on
    • bit5: 0=front LED off; 1=front LED on
  • RGB LEDs: for each LED, it is specified in sequence the value of red, green and blue (0...100)
  • sound id: 0x01=MARIO, 0x02=UNDERWOLRD, 0x04=STARWARS, 0x08=4KHz, 0x10=10KHz, 0x20=stop sound

For example to receive the camera image (stream) the following steps need to be followed:
1) connect to the robot through TCP
2) send the command packet:

0x80 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

3) read the ID (1 byte) and the QQVGA color image pakcet (38400 bytes)
4) go to step 3

Webots

TBD

ROS

TBD