Get the CyphalCAN messages with the UCAN board

This page will describe how to get the CyphalCAN BMS messages with the UCAN board

First make sure the BMS is connected to the UCAN board

Connect the CypahlCAN device (like the RDDRONE-UCANS32K146) to the BMS using JST GH 4 pin connectors with 1 on 1 wires. End the CAN bus with a 120Ω terminator resistor between CAN high and CAN low.

Get the BMS draft using the UCAN board in linux:

1. Connect the UCAN board with a USB-TTL-3V3 cable to the laptop.

2. Install the can utils with the following terminal command:

   • sudo apt install can-utils

3. Install python 3.7 with the following terminal command:

   • sudo apt install python3.7

4. Install pyuavcan with the following terminal command:

   • python3.7 -m pip install pyuavcan

5. Start the deamon on UART <-> SLCAN to use SLCAN0 use the command (for ttyUSB1):

   • sudo slcand -o -s8 -t sw -S 115200 /dev/ttyUSB1

Keep in mind that in this case the UART of the UCAN board needs to be connected to ttyUSB1. You can check which USB it is by disconnecting the USB-TTL-3V3 cable connected to the UCAN board, write “ls /dev” in the terminal, connect the USB cable and write “ls /dev” again. Only the USB of the UCAN board should be added in the list. If not check if the USB connection of your virtual machine is passed through.

1. Enable the interface (up)(same as ifup can0 in nuttx) write the following command:

   • sudo ip link set up slcan0

2. Clone the cannode v1 tools:

   • git clone https://github.com/PetervdPerk-NXP/cannode-v1-tools

3. Make sure the sub modules are in the git repository write the following command in the cannode-v1_tools directory:

   • git submodule update --init

4. Find this line in print_bmsstatus_topic.py:

   • media = pyuavcan.transport.can.media.socketcan.SocketCANMedia('can0', mtu=8)

5. Change it to the right can device, for example:

   • media = pyuavcan.transport.can.media.socketcan.SocketCANMedia('slcan0', mtu=8)

6. Run the pyuavcan tool by typing the following in a terminal where the print_bmsstatus_topic.py file is located:

   • python3.7 print_bmsstatus_topic

Keep in mind that the BMS needs to be configured correctly, see the CyphalCAN chapter of the SOFTWARE GUIDE - NUTTX.