Timing Issue with app_uart_put()?

RE: Timing Issue with app_uart_put()?

Akshay — Wed, 14 Dec 2016 23:20:16 GMT

I guess one modification you needed in your code was this, not sure if this was your actual problem. It was skipping few character for me.

 void uart_print(char *str){   
    int i = 0;
    while (str[i] != '\0'){
        while(app_uart_put(str[i])!= NRF_SUCCESS);
        i++;
    }
 }

void uart_println(char *str){
    uart_print(str);
    while(app_uart_put('\n')!= NRF_SUCCESS);
}

The 'app_uart_put' function needs to wait before the previous characters which you have already put are sent, Hence the while loop. Hope this will help others.

RE: Timing Issue with app_uart_put()?

Josh Grob — Wed, 09 Nov 2016 04:08:10 GMT

UPDATE

I did some digging in the SDK (V11), and I came across the RTT/UART logging (NRF_LOG) apis. I switched over the code to use those APIs work great and I can log out the values I need. Thus, in short I had a bad implementation, and doesn't make sense to troubleshoot my original question anymore (Doah!). Sorry for the errant post before doing my homework.

Thank you!

P.S - I implemented the NRF_LOG_USES_RAW_UART option, and nrf_log.c failed since it couldn't find UART0_CONFIG_BAUDRATE macro. I added "nrf_drv_uart.h" and everything works well now.

RE: Timing Issue with app_uart_put()?

Josh Grob — Tue, 08 Nov 2016 22:20:05 GMT

As an update I think I am hitting a seg fault since the chip keeps resetting, and faulting at the same place each time. The SIGTrap is a red herring I think since the debugger stops at the program entry point again on reset (I think). When the firmware runs without gdb, I see the crashing and resetting behavior in a loop. Now to find where the memory is getting corrupted...