TLE9879 can't send LIN message

[User15455]

Hello,

I used the TLE9879 demo code(driving a BLDC motor with sensorless FPC controlled over LIN) to develop our project.  Sometimes LIN didn't work properly. TLE9879 could received messages from the master, but it couldn't send messages back to the master. Could you please help to check what's the root cause? Thanks

[Kevin_Wu]

Hi there,

   for LIN communication, the master and slave are different in HW and SW.

For HW:  master node need 1K resister to bus

and slave is  30K

For SW, make sure it is right.

thanks, Kevin

[User15455]

Hi Kevin,

It seems 9879 goes into receive-only mode at low voltage. How to recover from receive-only mode without power cycle? Thanks 

[Kevin_Wu · Accepted solution]

Hi there,

 According to spec. 

• LROM(LIN receiver only mode) - LNM (LIN normal mode) transition is executed when:
– CTRL_STS.MODE is configured to LIN Normal Mode and
– Feedback signals of Mode and Slope Mode are ok (see Chapter 20.3.2) and
– VS undervoltage flag (SYS_SUPPLY_IRQ_STS.VS_UV_STS) is not set and
– LIN transceiver CTRL_STS.OT_STS and CTRL_STS.OC_STS are not set and LIN transceiver
– no CTRL_STS.TXD_TMOUT is set

After voltage goes normal, the  VS Undervoltage flag will goes to 0, as it is ready only register and controlled by HW.   so if all configuration is right, the LIN should goes to normal mode.

Thanks, Kevin