pic32mx UART problem

ulmus71 wrote on Wednesday, January 11, 2012:

Anyone has ever met problem with interrupt driven transmition?
I noticed that after setting int flag for transmit interrupt, the interrupt is never comming :frowning: i cant figure out what is going on. Writing directly to transmit register is working but starting transmition by writing just like in demo doesnt work:( no interrupt at all :frowning:
p.s. im using mplab 8.7 with 2.0.2 compiler and microchip starter kit with pic32mx360f512
I know it is not freertos problem, but maybe someone has met this problem and can help, thanx!

rtel wrote on Wednesday, January 11, 2012:

I don’t know directly, but something to watch out for that has caught other people out.

The FreeRTOS demo comes with (if I recall correctly) some basic UART interrupt code, and it works on the part on which it was developed.  The original parts was one of the first PIC32 devices to be released.  I know the same code does not work on the later parts, and specifically those found on the Ethernet and USB II starter kits, because the interrupt mechanism internal to the UART peripheral was changed.  I can’t remember exactly what, but it was something to do with having to clear the interrupt as the first instruction in the handler (?) due to some level or edge sensing change.

I don’t know if that is related to your problem, and sorry I can’t be more specific.  If you think it might be related then you can find more information somewhere on this forum, although searching is not that easy.