RTOS/MSP432P401R: Garbage on UART RX causing crash

ferdster

Part Number: MSP432P401R

Tool/software: TI-RTOS

Hi,

I'm using the display driver with the default settings (MSP_EXP432P401R_UARTA0 on pins UARTMSP432_P1_2_UCA0RXD/UARTMSP432_P1_3_UCA0TXD). Is there a way to undefine or not use the RX pin? Our board has some sort of weird coupling issue where some stray signals are getting on the RX line causing the MSP432 to lock up. Why would a signal, whatever it is, cause the MCU to crash? We stopped the crashing by simply cutting the RX trace right at the MCU pin.

Thanks.

over 6 years ago

0 John P. Morrison over 6 years ago

TI__Intellectual 2405 points

Can you give some more information about what you mean by "crash" in this case? Are you able to run this in debug mode and give some more details about what you are seeing?

0 ferdster over 6 years ago in reply to John P. Morrison

Expert 1125 points

Basically, we are running a continuous loop where we read sensors and I print the data out on UART0 (PuTTY). Every now and then we would see garbage interspersed with the real data.

Sometimes it would start printing out garbage continuously and then stop printing all together. From looking at the current draw we could tell that the loop was not running anymore - this is what I mean by crash.

I could run it in debug mode if you could give me a quick tutorial on how, or point me to an online tutorial.

Thanks.

0 John P. Morrison over 6 years ago in reply to ferdster

TI__Intellectual 2405 points

What platform are you developing this on? CCS, KEIL, IAR, Energia? It will be different for each.

0 ferdster over 6 years ago in reply to John P. Morrison

Expert 1125 points

Hi, I am using CCS 7.2.

Thanks.

0 John P. Morrison over 6 years ago in reply to ferdster

TI__Intellectual 2405 points

So that I am clear, are you asking for help with basic debugging techniques?

Are you familiar with how to use a screen similar to the following?

0 ferdster over 6 years ago in reply to John P. Morrison

Expert 1125 points

I don't see any image in your post. I've only used the debugger with breakpoints. I assume there is a way to monitor variables, registers, etc. 'live' while the program is running?

Thanks.

0 John P. Morrison over 6 years ago in reply to ferdster

TI__Intellectual 2405 points

My apologies, for some reason when I copy paste pictures into my reply it doesn't work so well it seems. I believe I have modified the previous post so that a picture is visible now.

OK, yes debugger with breakpoints is basically what I am talking about. But you can also use the view tab to add other useful windows. In the picture I've added ( it appears to have worked this time, hopefully) it shows a small window in the upper right corner which has tabs for registers, watch expressions and variables. These update at breakpoints or whenever you pause the program and are very useful debugging tools (the picture I have posted is from Code Composer Studio).

0 ferdster over 6 years ago in reply to John P. Morrison

Expert 1125 points

Ok, I'll do that the next time I get the chance. Currently our units are sealed and I can't access the JTAG.

Just for clarification, it's not possible to look at variables/registers live while the program is running, correct? The values only update at breakpoints or when pausing execution.

Thanks.

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RTOS/MSP432P401R: Garbage on UART RX causing crash