linux-can/can-doc

Linux-CAN / SocketCAN documentation

can-doc's Issues

Issue with bus.send_periodic

Hi, I'm trying to send CAN messages with the function send_periodic. however i got the error

can.exceptions.CanOperationError: Couldn't send CAN BCM frame due to OS Error: Invalid argument You are probably referring to a non-existing frame. [Error Code 22]

The code i used is :

import can
import time

try:
    bus = can.interface.Bus(channel = 'can0',
                            bustype = 'socketcan',
                            bitrate = 500000)
except OSError as e:
    print(e)

message = can.Message(arbitration_id=0x37A, data=[0x0A, 0x00, 0x3B, 0x00, 0xFF, 0x0B, 0x00, 0x00], is_extended_id= False)
message1 = can.Message(arbitration_id=0x379, data=[0x0C, 0x00, 0x0A, 0x00, 0xFF, 0x00, 0x0A, 0x00], is_extended_id= False)
message2 = can.Message(arbitration_id=0x372, data=[0x00, 0xD0, 0x50, 0x80, 0xCC, 0x00, 0xAA, 0xB0], is_extended_id= False)

period = 0.1

while True:
    bus.send_periodic(msgs = message, period = 0.1)
    bus.send_periodic(msgs = message1, period = 0.1)
    bus.send_periodic(msgs = message2, period = 0.1)

When i tried to send it via bus.send it seems to be able to work

import can
import time

bus = can.interface.Bus(channel='can0', bustype='socketcan')
    
message = can.Message(arbitration_id=0x37A, data=[0x0A, 0x00, 0x3B, 0x00, 0xFF, 0x0B, 0x00, 0x00], is_extended_id= False)
message1 = can.Message(arbitration_id=0x379, data=[0x0C, 0x00, 0x0A, 0x00, 0xFF, 0x00, 0x0A, 0x00], is_extended_id= False)
message2 = can.Message(arbitration_id=0x372, data=[0x00, 0xD0, 0x50, 0x80, 0xCC, 0x00, 0xAA, 0xB0], is_extended_id= False)


period = 0.1

while True:
    bus.send(message)
    time.sleep(period)
    bus.send(message1)
    time.sleep(period)
    bus.send(message2)
    time.sleep(period)

Here are some of the configurations that my CAN device is working on
RPI-4B 8GB Ram,
kernel version : 6.1.19-v8+
CAN transceiver device, MCP2515 (modified, changed VP230 for TJA1050)

ip -d -s link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10
    link/can  promiscuity 0 minmtu 0 maxmtu 0 
    can state ERROR-ACTIVE restart-ms 100 
    
lsmod | grep spi
spidev                 20480  2
spi_bcm2835            20480  0

 ifconfig can0
can0: flags=193<UP,RUNNING,NOARP>  mtu 16
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 10  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

/boot/config.txt
dtparam=spi=on
dtoverlay=mcp2515, spi0-0, interrupt=25,oscillator=8000000
dtoverlay=spi-dma
dtoverlay=spi-bcm2835

Upon boot up, RPI did say that it is unable to load spi-dma & bcm2835

failed to load dtoverlay=spi-dma
failed to load dtoverlay=spi-bcm2835

I'm pretty new to RPI and CAN devices as well as posting issues on github, so any advice would definitely help! Thanks