I’m using the EMX module to communicate to another device (LPC11C14). It worked on using the EMX Dev board. I now built my own hardware using a MCP2551 transceiver. On my board it does not work.
When I try to send a message it goes to BusOff error immediately. I measured to see if there is data out from the EMX module’s CAN TD1 pin and I get a single “pulse” but on the CAN RD1 pin there is no “pulse”, and if I am not mistaken CAN monitors the RD pin while transmitting.
I can however receive data from the LPC11C14 chip. I used the exact same circuit for the CAN transceiver on the EMX board as I have used on the LPC board.
EMX PIN23 to MCP PIN1
EMX PIN25 to MCP PIN4
MCP PIN2 to GND
MCP PIN3 to 5V
MCP PIN5 left open
MCP PIN8 to 10k to GND
I have a 120 Ohm resistor at either side of the BUS.
I know it is not the code as it works perfectly on the DEV SYS. And I can’t see anything wrong on the hardware side.
Is there anything I can look at that I might have missed?
Any help is greatly appreciated.