Issue with bus.send_periodic

[YuBer0]

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

[marckleinebudde]

This repository is about datasheets of CAN IP cores, not about general support.

I'm not sure if the BCM is compiled into the raspi Linux kernel by default. Please check if it's loaded, after booting check the kernel log: dmesg | grep -i can.

[YuBer0]

Hi thank you for the prompt reply,
how should i shift the issue to general support?

as for kernel log: dmesg | grep - i can
the output is

CAN device driver interface
MCP251x spi0.0 can0: MCP2515 successfully initialized.
CAN: controller area network core
NET: Registered PF_CAN protocol family
IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready

[marckleinebudde]

It doesn't show can: broadcast manager protocol, so BCM is not compiled into the kernel. You have to recompile your kernel with CAN_BCM enabled.

I'm sure, you'll find a low of documentation, if you search for "how to compile kernel for raspberry pi".

[YuBer0]

Hi, i managed to recompile my kernel with CAN_BCM enabled. via resources this link

i check the kernel log: dmesg | grep -i can and the output i get is:

CAN device driver interface
MCP251x spi0.0 can0: MCP2515 successfully initialized.
CAN: controller area network core
NET: Registered PF_CAN protocol family
CAN: raw protocol
IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
CAN: broadcast manager protocol

However the same error persist when i try to use the function send_periodic. Also when i reboot the system, it seems like the CAN: broadcast manger protocol is not shown after i typed dmesg | grep -i can in kernel

[marckleinebudde]

However the same error persist when i try to use the function send_periodic. Also when i reboot the system, it seems like the CAN: broadcast manger protocol is not shown after i typed dmesg | grep -i can in kernel

If the BCM is a module it's only loaded if needed, so after you run your test program the first time.

Try running as root, if this doesn't work, maybe @hartkopp can help you.

[YuBer0]

I see. this is helpful.
i managed to see the CAN: broadcast manger protocol is not shown after i typed dmesg | grep -i can in kernel now, however i still face the same error message:

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]

[hartkopp]

I tried the original code from #2 (comment) and only changed can0 to vcan0 . That resulted in a working setup.

But candump any -td shows that the gap between the CAN frames is only about some micro seconds:

 (000.000030)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000045)  vcan0  379   [8]  0C 00 0A 00 FF 00 0A 00
 (000.000036)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000015)  vcan0  372   [8]  00 D0 50 80 CC 00 AA B0
 (000.000040)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000044)  vcan0  379   [8]  0C 00 0A 00 FF 00 0A 00
 (000.000044)  vcan0  372   [8]  00 D0 50 80 CC 00 AA B0

This would be definitely too fast for a real CAN bus.

Additionally this looks wrong:

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)

You are creating a busy loop which continuously overwrites the current CAN_BCM setting to establish a periodic send job!

You likely wanted to have

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

while True:
    time.sleep(1)

which leads to this output of candump any -td :

 (000.100444)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000030)  vcan0  379   [8]  0C 00 0A 00 FF 00 0A 00
 (000.000019)  vcan0  372   [8]  00 D0 50 80 CC 00 AA B0
 (000.100024)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000095)  vcan0  379   [8]  0C 00 0A 00 FF 00 0A 00
 (000.000015)  vcan0  372   [8]  00 D0 50 80 CC 00 AA B0
 (000.100278)  vcan0  37A   [8]  0A 00 3B 00 FF 0B 00 00
 (000.000019)  vcan0  379   [8]  0C 00 0A 00 FF 00 0A 00
 (000.000013)  vcan0  372   [8]  00 D0 50 80 CC 00 AA B0

[YuBer0]

Hello Hartkopp, thank you for the reply!
I yes you are right regarding the while True loop. i changed the loop portion of the code to what you have suggested, however i still face the same error code.
I'm not too sure do i have to download or install any other libraries in order to use BCM on RPI with a physical CAN device?

[hartkopp]

Can you please check is it works with a virtual CAN interface in your setup (as I showed above) and check if the CAN traffic is analogue to my candump example?
We have to figure out if it is a CAN driver or BCM problem.

[YuBer0]

Sure, i just tried with your changes, and it's have the same error message.
I'm curious, as i manage to use can.send, does it mean that would be a chance where the CAN driver has issue?

[hartkopp]

Can you please post the output of lsmod | grep can and ip -d -s link show vcan0?

[YuBer0]

Sure!

[hartkopp]

lsmodlooks good.

But there are no RX/TX packets on the vcan0 interface.

When I run your program on vcan0instead of can0 it looks like this:

$ ip -d -s link show vcan0
3: vcan0: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/can  promiscuity 0  allmulti 0 minmtu 0 maxmtu 0 
    vcan numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 tso_max_size 65536 tso_max_segs 65535 gro_max_size 65536 
    RX:  bytes packets errors dropped  missed   mcast           
         29936    3742      0       0       0       0 
    TX:  bytes packets errors dropped carrier collsns           
         29936    3742      0       0       0       0 

[YuBer0]

I'm unable to run the code, because when i try to run it, the err code 22 came up.
Can i check with you is there any other settings or configuration that i might have missed out on?

[marckleinebudde]

Please show the code you're trying to run. This work-for-me:

import can                                                                                                                                                                                                                                                      
import time                                                                                                                                                                                                                                                     
                                                                                                                                                                                                                                                                
try:                                                                                                                                                                                                                                                            
    bus = can.interface.Bus(channel = 'vcan0',                                                                                                                                                                                                                  
                            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                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                
bus.send_periodic(msgs = message, period = 0.1)                                                                                                                                                                                                                 
bus.send_periodic(msgs = message1, period = 0.1)                                                                                                                                                                                                                
bus.send_periodic(msgs = message2, period = 0.1)                                                                                                                                                                                                                
                                                                                                                                                                                                                                                                
while True:                                                                                                                                                                                                                                                     
        time.sleep(1)