DeepDrive Motor Controller Firmware

TODO

• restart esp32 if it can't connect
• Beeps/music
• Use multicore FreeRTOS to run motor loop on one core and micro ros loop on another
• Calibrate both motors at the same time on 2 cores
• Timeout on cmd_vel - stop the motors, reboot after this and trying pings for a while

Hardware

• Jetson Orin Nano
• Makerbase ESP32 Dual Brushless Micro FOC V1.0
• Hoverboard motors - got mine from Marketplace or you can do something like this
• Buck Converter
• MOSFET
• Power Button
• Toggle Switch
• Battery - maybe 3S 11.1v or 4s 14.8v LiPo battery
• XT60 connectors
• 18AWG Silicone Wire
• 1.5k resistors for pulling up hall encoder lines
• 6Pin JST 2.54mm PH Connectors for hall encoders
• Heat shrink tubing

Software

• Micro ROS - ROS2 Communication
• SimpleFOC - Brushless motor controller library

Setup

Add user to dialout group

sudo usermod -a -G dialout $(whoami)

Install PlatformIO

https://docs.platformio.org/en/latest/core/installation/index.html

curl -fsSL -o get-platformio.py https://raw.githubusercontent.com/platformio/platformio-core-installer/master/get-platformio.py
python3 get-platformio.py

Clone

git clone git@github.com:mattwilliamson/deepdrive_motor_controller.git
cd deepdrive_motor_controller
echo 'PATH="$HOME/.platformio/penv/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc
pio run

Missing drivers

If your device doesn't show up in sudo dmesg then you might need to re-install drivers:

cd /opt
sudo git clone https://github.com/juliagoda/CH341SER
cd CH341SER
sudo make clean 

sudo make

# If using secure boot
# https://ubuntu.com/blog/how-to-sign-things-for-secure-boot
#kmodsign sha512 /var/lib/shim-signed/mok/MOK.priv /var/lib/shim-signed/mok/MOK.der ./ch34x.ko

sudo make load
lsmod | grep ch34*

sudo make install

unplug and plug it back in again

$ sudo dmesg -w
[ 5324.176691] usbserial: USB Serial support registered for ch34x
[ 5324.176734] ch34x 1-1.3:1.0: ch34x converter detected
[ 5324.181802] usb 1-1.3: ch34x converter now attached to ttyUSB0

Set EEPROM/Flash to store which motor it is

Once the program is flashed, we will need to connect one motor controller at a time and then flash the eeprom (emulated in flash) with the value of which side it is on.

Plug in MKS ESP32 FOC while powered up and get device details one at a time:

Remove braile support so ttyUSB works with CH431 Serial device:

sudo apt remove brltty 

sudo dmesg -w

[  688.466785] usb 1-2.1: new full-speed USB device number 4 using tegra-xusb
[  688.573443] usb 1-2.1: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[  688.573452] usb 1-2.1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  688.573457] usb 1-2.1: Product: USB Serial
[  688.611179] usbcore: registered new interface driver ch341
[  688.611200] usbserial: USB Serial support registered for ch341-uart
[  688.611241] ch341 1-2.1:1.0: ch341-uart converter detected
[  688.618337] usb 1-2.1: ch341-uart converter now attached to ttyUSB0

[ 1181.973673] usb 1-2.4: new full-speed USB device number 5 using tegra-xusb
[ 1182.080331] usb 1-2.4: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[ 1182.080340] usb 1-2.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 1182.080344] usb 1-2.4: Product: USB Serial
[ 1182.082561] ch341 1-2.4:1.0: ch341-uart converter detected
[ 1182.089568] usb 1-2.4: ch341-uart converter now attached to ttyUSB1

Set a symlink alias

To distinguish between other devices, like GPS

cat << EOF | sudo tee /etc/udev/rules.d/99-motor_controller.rules
KERNEL=="ttyUSB[0-9]*", SUBSYSTEMS=="usb", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE:="0777", SYMLINK+="ttyMotor%n"
EOF

# Reload the rules
sudo udevadm control --reload-rules && sudo udevadm trigger

Check it

matt@deepdrive:~$ ls /dev/ttyMotor*
/dev/ttyMotor0  /dev/ttyMotor1

Flash it! (or just use VSCode PlatformIO serial monitor)

$ sudo apt-get install screen
$ screen /dev/ttyMotor0 115200

Please enter 'left' or 'right' to set the side:
left

Connect to ROS2

# source $UROS_WS/install/setup.sh && \
# ros2 run micro_ros_setup create_agent_ws.sh && \
# ros2 run micro_ros_setup build_agent.sh

$ cd ~/src/deepdrive
$ make dockershell
$ MOTORS=`ls /dev/ttyMotor*`
$ ros2 run micro_ros_agent micro_ros_agent multiserial --devs "$MOTORS" -v6

Connect to ROS2 (Docker)

DISTRO="humble"
LEFT="/dev/serial/by-path/platform-3610000.xhci-usb-0:2.1:1.0-port0"
RIGHT="/dev/serial/by-path/platform-3610000.xhci-usb-0:2.3:1.0-port0"

sudo docker run -it --rm -v /dev:/dev --privileged --net=host microros/micro-ros-agent:$DISTRO multiserial --devs "$LEFT $RIGHT" -v6

# sudo docker run -it --rm -v /dev:/dev --privileged --net=host microros/micro-ros-agent:humble serial --dev /dev/serial/by-path/platform-3610000.xhci-usb-0:2.4:1.0-port0 -v6

Usage

Show/echo topics

$ ros2 node list
/motor/right/motor_right_node

$ ros2 topic list
/motor/left/back/angle
/motor/left/back/vel/cmd
/motor/left/front/angle
/motor/left/front/vel/cmd
/motor/right/back/angle
/motor/right/back/vel/cmd
/motor/right/front/angle
/motor/right/front/vel/cmd
/parameter_events
/rosout

$ ros2 topic echo /motor/right/front/angle
data: 18
---
data: 18
---
data: 18
---

Set radians/s velocity

$ ros2 topic info /motor/right/front/vel/cmd
Type: std_msgs/msg/Float64
Publisher count: 0
Subscription count: 1

$ ros2 topic pub --once /motor/right/front/vel/cmd std_msgs/Float64 '{"data":1.0}'

Wiring

When connected directly to a 3s LiPo battery, I burned out 3 ESP32 modules before adding the buck converter. The buck converter has current limiting, eh8ch has also helped the USB bus from browning out.

The power button enables power theough the MOSFET for the whole system. The toggle switch turns on the power for the buck converter. This allows killing the motors if they go crazy or carch fire like mine did before I added the buck converter.

I did have to solder on a resistor for the power button LED.

For my throw switch, I had to mod it because the buck converter switch logic is inverterted. It is poowered on when the signal is pulled low. I just took the covere off and reversed it. I could have also just soldered a transistor here, which might be preferrable.

todo:

• switches
• buck converter
• hall encoder
• pullups
• esp32
• motors

Based on:

https://github.com/micro-ROS/micro_ros_platformio?tab=readme-ov-file#how-to-add-to-your-project

https://github.com/micro-ROS/micro_ros_platformio/blob/main/examples/micro-ros_publisher/src/Main.cpp

https://github.com/micro-ROS/micro-ROS-demos/tree/jazzy/rclc/int32_publisher_subscriber