I am trying to use FlexCAN on MPC5777C-516DS board without motherboard. So, I use DB9 (connected to GPIO and GPIO pins of MPC5777C) to connect with other CAN interface device for test communication. Jumpers on MPC5777C-516DS: J506 1-2, 4-5; j507 1-3, 2-4.
I am referring example "Example-MPC5777C-FlexCAN-simpleTXRX-ECCdisabled-GHS616" (but work only with FlexCAN_A which connected to DB9). After upload the program I have next scenario:
- FlexCAN_A_Init() - successful;
- Trying to send 1 byte, ext. frame with CANA_TransmitMsg();
- Can not pass endless loop "while ( CAN_A.IFLAG1.B.BUF31TO8I == 0)"
- Look at Error and Status 1 register (CAN_ESR1). It have 0x4036 value (Buss off, Bit0 error).
I checked up physical connection and signals on CAN bus:
- physical connection is ok;
- when I send 1 byte from MPC5777C-516D I have some signals on CNTXA line (attachment "CANbus_CNTXA.jpg"), but have no signal on CAN bus after MC33908LAE transceiver.
- when I send 1 byte from my other CAN interface device to MPC5777C-516D, I have signals on CAN bus and the similar signal on CNRXA line (attachment "CANbus_CNRXA.jpg"). But CAN interface device reports an timeout error (like it is only 1 device on CAN bus).
Please suggest what kind of problem it can be.
seems the CAN transmitter is disabled, but it should be in normal mode if the SBC is put into Debug mode.
Do you mean CAN transmitter "MC33908LAE" (placed on MPC5777C-516D) is disabled?