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I am executing a python and can code to make a data log but when I run it I get the error Transmit buffer full

This is the code

#!/usr/bin/python3 # ## obdii_logger.py # # This python3 program sends out OBDII request then logs the reply to the sd card. # For use with PiCAN boards on the Raspberry Pi # http://skpang.co.uk/catalog/pican2-canbus-board-for-raspberry-pi-2-p-1475.html # # Make sure Python-CAN is installed first http://skpang.co.uk/blog/archives/1220 # # 24-08-16 SK Pang #

import RPi.GPIO as GPIO
import can
import time
import os
import queue
from threading import Thread

led = 22
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(led,GPIO.OUT)
GPIO.output(led,True)

# For a list of PIDs visit https://en.wikipedia.org/wiki/OBD-II_PIDs
ENGINE_COOLANT_TEMP = 0x05
ENGINE_RPM          = 0x0C
VEHICLE_SPEED       = 0x0D
MAF_SENSOR          = 0x10
O2_VOLTAGE          = 0x14
THROTTLE            = 0x11

PID_REQUEST         = 0x7DF
PID_REPLY           = 0x7E8

outfile = open('log.txt','w')


print('\n\rCAN Rx test')
print('Bring up CAN0....')

# Bring up can0 interface at 500kbps
os.system("sudo /sbin/ip link set can0 up type can bitrate 500000")
time.sleep(0.1) 
print('Ready')

try:
    bus = can.interface.Bus(channel='can0', bustype='socketcan')
except OSError:
    print('Cannot find PiCAN board.')
    GPIO.output(led,False)
    exit()

def can_rx_task():  # Receive thread
    while True:
        message = bus.recv()
        if message.arbitration_id == PID_REPLY:
            q.put(message)          # Put message into queue

def can_tx_task():  # Transmit thread
    while True:

        GPIO.output(led,True)
        # Sent a Engine coolant temperature request
        msg = can.Message(arbitration_id=PID_REQUEST,data=[0x02,0x01,ENGINE_COOLANT_TEMP,0x00,0x00,0x00,0x00,0x00], is_extended_id=False)
        bus.send(msg)
        time.sleep(0.05)

        # Sent a Engine RPM request
        msg = can.Message(arbitration_id=PID_REQUEST,data=[0x02,0x01,ENGINE_RPM,0x00,0x00,0x00,0x00,0x00], is_extended_id=False)
        bus.send(msg)
        time.sleep(0.05)

        # Sent a Vehicle speed  request
        msg = can.Message(arbitration_id=PID_REQUEST,data=[0x02,0x01,VEHICLE_SPEED,0x00,0x00,0x00,0x00,0x00],is_extended_id=False)
        bus.send(msg)
        time.sleep(0.05)        

        # Sent a Throttle position request
        msg = can.Message(arbitration_id=PID_REQUEST,data=[0x02,0x01,THROTTLE,0x00,0x00,0x00,0x00,0x00],is_extended_id=False)
        bus.send(msg)
        time.sleep(0.05)
        
        GPIO.output(led,False)
        time.sleep(0.1)
                        
                        
q = queue.Queue()
rx = Thread(target = can_rx_task)  
rx.start()
tx = Thread(target = can_tx_task)
tx.start()

temperature = 0
rpm = 0
speed = 0
throttle = 0
c = ''
count = 0

# Main loop
try:
    while True:
        for i in range(4):
            while(q.empty() == True):   # Wait until there is a message
                pass
            message = q.get()

            c = '{0:f},{1:d},'.format(message.timestamp,count)
            if message.arbitration_id == PID_REPLY and message.data[2] == ENGINE_COOLANT_TEMP:
                temperature = message.data[3] - 40          #Convert data into temperature in degree C

            if message.arbitration_id == PID_REPLY and message.data[2] == ENGINE_RPM:
                rpm = round(((message.data[3]*256) + message.data[4])/4)    # Convert data to RPM

            if message.arbitration_id == PID_REPLY and message.data[2] == VEHICLE_SPEED:
                speed = message.data[3]                                     # Convert data to km

            if message.arbitration_id == PID_REPLY and message.data[2] == THROTTLE:
                throttle = round((message.data[3]*100)/255)                 # Conver data to %

        c += '{0:d},{1:d},{2:d},{3:d}'.format(temperature,rpm,speed,throttle)
        print('\r {} '.format(c))
        print(c,file = outfile) # Save data to file
        count += 1
            


    
except KeyboardInterrupt:
    #Catch keyboard interrupt
    GPIO.output(led,False)
    outfile.close()     # Close logger file
    os.system("sudo /sbin/ip link set can0 down")
    print('\n\rKeyboard interrtupt')

I tried the command sudo ifconfig can0 txqueuelen 1000 but I still keep getting the same error Transmit buffer full

Fabianh
  • 1

0 Answers0