I have a system which is configured with a Arduino Uno and sparkfuns CAN-bus shield.
A PEAK usb-can dongle is connected to the CAN-bus shield and is used to verify the messages that is sent received by the CAN-shield. Windows 10 with PCAN-view is used on the computerside.
It works fine to send CAN-messages from PCAN-view to the sparkfuns CAN-shield.
But when trying to send CAN-messages from the CAN-shield it works very bad. CAN-messages are very seldom seen in PCAN-view program. Sometime the same message is printed in PCAN-view program even though there is a counter updated in the data. This counter is not changed in the message.
The CAN-bus is terminated with 120ohms.
Examples from the sparkfuns github is used, https://github.com/sparkfun/SparkFun_CAN-Bus_Arduino_Library
Any ideas of what could be wrong?
Here is the write example that is used:
/****************************************************************************
CAN Write Demo for the SparkFun CAN Bus Shield.
Written by Stephen McCoy.
Original tutorial available here: http://www.instructables.com/id/CAN-Bus-Sniffing-and-Broadcasting-with-Arduino
Used with permission 2016. License CC By SA.
Distributed as-is; no warranty is given.
*************************************************************************/
#include <Canbus.h>
#include <defaults.h>
#include <global.h>
#include <mcp2515.h>
#include <mcp2515_defs.h>
//********************************Setup Loop*********************************//
void setup() {
Serial.begin(9600);
Serial.println("CAN Write - Testing transmission of CAN Bus messages");
delay(1000);
if(Canbus.init(CANSPEED_500)) //Initialise MCP2515 CAN controller at the specified speed
Serial.println("CAN Init ok");
else
Serial.println("Can't init CAN");
delay(1000);
}
//********************************Main Loop*********************************//
void loop()
{
tCAN message;
message.id = 0x631; //formatted in HEX
message.header.rtr = 0;
message.header.length = 8; //formatted in DEC
message.data[0] = 0x40;
message.data[1] = 0x05;
message.data[2] = 0x30;
message.data[3] = 0xFF; //formatted in HEX
message.data[4] = 0x00;
message.data[5] = 0x40;
message.data[6] = 0x00;
message.data[7] = 0x00;
mcp2515_bit_modify(CANCTRL, (1<<REQOP2)|(1<<REQOP1)|(1<<REQOP0), 0);
mcp2515_send_message(&message);
delay(1000);
}
Here is the read code that is used:
/****************************************************************************
CAN Read Demo for the SparkFun CAN Bus Shield.
Written by Stephen McCoy.
Original tutorial available here: http://www.instructables.com/id/CAN-Bus-Sniffing-and-Broadcasting-with-Arduino
Used with permission 2016. License CC By SA.
Distributed as-is; no warranty is given.
*************************************************************************/
#include <Canbus.h>
#include <defaults.h>
#include <global.h>
#include <mcp2515.h>
#include <mcp2515_defs.h>
//********************************Setup Loop*********************************//
void setup() {
Serial.begin(9600); // For debug use
Serial.println("CAN Read - Testing receival of CAN Bus message");
delay(1000);
if(Canbus.init(CANSPEED_500)) //Initialise MCP2515 CAN controller at the specified speed
Serial.println("CAN Init ok");
else
Serial.println("Can't init CAN");
delay(1000);
}
//********************************Main Loop*********************************//
void loop(){
tCAN message;
if (mcp2515_check_message())
{
if (mcp2515_get_message(&message))
{
//if(message.id == 0x620 and message.data[2] == 0xFF) //uncomment when you want to filter
//{
Serial.print("ID: ");
Serial.print(message.id,HEX);
Serial.print(", ");
Serial.print("Data: ");
Serial.print(message.header.length,DEC);
for(int i=0;i<message.header.length;i++)
{
Serial.print(message.data[i],HEX);
Serial.print(" ");
}
Serial.println("");
//}
}}
}