CAN4DISCO firmware

Written in http://ivorylang.org/

Tests

CANSendRecv

test application sending packets from CAN1, blinks on received packets.

CANLoop

test application sending packets from CAN1 to CAN2 and vice versa triggering LEDs on received messages.

CAN2UART

can2uart bridge

SLCANLoopback

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.

SLCAN

Standalone UART2 <-> CAN1 bridge

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/can4disco-uart can0 # CAN speed 8 -> 1Mbit
ip link set can0 up
candump can0
cansend can0 1F334455#112233445566778
cansend can0 1EF#11223344556677FF

You can also use:

make slcan-setup

to execute ./util/setup script (runs commands above, requires sudo).

Debugging SLCAN

To send raw messages to can4disco:

echo -n -e 'TFF3344558DEADBEEFAABBCCDD\r' > /dev/can4disco-uart
echo -n -e 't1234DEADBEEF\r' > /dev/can4disco-uart

To fake UART for slcand use:

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

run screen on one side:

screen /dev/ttyS1 115200

and point slcand to it:

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:

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

run tower_init on one side:

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

and slcand on the other side:

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

Testing hardware

Load loopback firmware:

make canloop-test

Connect CAN1 L to CAN2 L and CAN1 H to CAN2 H to create a hardware loopback, after bridging both transcievers RX/TX LEDs should start blinking indicating reception on both interfaces.