topic LPC11C14 - problem during CAN communication in LPC Microcontrollers

LPC11C14 - problem during CAN communication

lpcware — Wed, 15 Jun 2016 19:45:03 GMT

Content originally posted in LPCWare by mattiad on Fri Oct 24 02:55:59 MST 2014
Dear All,

I've noticed a problem using the LPC11C14 for CAN communication.
Micro is connected to an external TJA1040 driver. If I turn off the suplly voltage for a small period the micro doesn't reset (the 3,3V doesn't drop) but the Driver supply (5V) drops immediately, creating problem with CAN communication. In this case the micro doesn't communicate anymore with CAN ports. Everithing is working well with the micro (UART communication, SPI communication ect.) but the CAN ports don't communicate.
Is there a way to make the micro detecting this ports' block and reset this?

Thank you in advance,

Mattia

Re: LPC11C14 - problem during CAN communication

lpcware — Wed, 15 Jun 2016 19:45:04 GMT

Content originally posted in LPCWare by Ano on Sun Nov 16 14:39:27 MST 2014
Did you measure the can output pins of the microcontroller? Is he really not sending anything, or is the TJA1040 just getting the data but not sending it out?
Assuming the TJA1040 is causing the problems and not the microcontroller:
I'm not too familiar with CAN, so I see no option to detect that without hardware around it. Like a Schmitt-Trigger that compares the 5V (divided by voltage divider) with the
3V rail and sets an external interrupt flag or something. But even then, you can detect it, but can't do anything about it, if you can't reset the TJA1040 by cutting the power or something.