CAN4DISCO firmware

Written in



dnf install arm-none-eabi-gcc-cs arm-none-eabi-newlib


To build all images:

./ # required if you don't have checked out ivory tower and ivory-tower-stm32 repos in ..


test application sending packets from CAN1, blinks on received packets. Image available in build/cansendrecv-test/image
test application sending packets from CAN1 to CAN2 and vice versa triggering LEDs on received messages. Image available in build/canloop-test/image
can2uart bridge Image available in build/can2uart-test/image
SLCAN loopback test. Connect CAN1 to CAN2 create loopback for SLCAN. SLCAN messages sent to UART2 will flow thru CAN1->CAN2 back to UART2, see SLCAN usage for more information. Image available in build/slcan-test/image
Standalone UART2 <-> CAN1 bridge


With BlackMagic Probe:

arm-none-eabi-gdb --ex 'target extended-remote /dev/ttyACM0' --ex 'monitor swdp_scan' --ex 'attach 1' --ex 'load' build/canloop-test/image

SLCAN usage

SLCAN allows transmission of decapsulated CAN frames over UART. To create UART<->CAN bridge with Linux kernel use:

modprobe can
modprobe can-raw
modprobe slcan
slcand -F -s8 -S115200 /dev/f4uart can0 # CAN speed 8 -> 1Mbit
ip link set can0 up
candump can0
cansend can0 1F334455#112233445566778
cansend can0 1EF#11223344556677FF

Debugging SLCAN

To send raw messages to can4disco:

echo -n -e 'TFF3344558DEADBEEFAABBCCDD\r' > /dev/f4uart
echo -n -e 't1234DEADBEEF\r' > /dev/f4uart

To fake UART for slcand use:

sudo socat -d -d pty,link=/dev/ttyS0,raw,echo=0 pty,link=/dev/ttyS1,raw,echo=0

run screen on one side:

sudo screen /dev/ttyS1 115200

and point slcand to it:

sudo slcand -F -s8 -S115200 /dev/ttyS0 can0

Running SLCAN POSIX Loopback

It is possible to run slCANTower on POSIX with the help of ivory-tower-posix.

Build the executable with:

make slcan-posix-loopback-test

Link ttyS0 and ttyS1:

sudo socat -d -d pty,link=/dev/ttyS0,raw,echo=0 pty,link=/dev/ttyS1,raw,echo=0

run tower_init on one side:

sudo ./build/slcan-posix-loopback-test/tower_init <> /dev/ttyS1 > /dev/ttyS1

and slcand on the other side:

sudo slcand -F -s8 -S115200 /dev/ttyS0 can0
sudo ip link set can0 up

Try dumping and sending some data, your messages should appear twice as there is an loopback in tower_init:

candump can0
cansend can0 000#0201