Low memory RTT alternative

[pltv]

I am trying to program a custom board connected via the DK. The custom board is 16KB version (nRF51822 QFAA). RTT consumes lot of memory and hence my code does not compile with RTT. It compiles well without RTT. However i need to debug my program execution and see where things are failing. While my custom logic runs fine on the DK i have some issues with the custom board. I am not sure if UART trace will be a solution since it has overheads and is expected to run slower. Is there an alternative?

Best Prasanna

[RK]

You can choose how much memory RTT uses by configuring the number of up and down buffers and the max size. I think the default config has 2 up, 2 down with 1k of memory for the down and not much for the up. If you reduce that to 1 buffer of much smaller size can you get it to work?

Are you compiling in that SEGGER printf function, that takes a lot of code space, if you can avoid using that it's better.

[Øyvind Karlsen]

I think you will find this blog useful.

[pltv]

Thanks RK. This helped me with my debugging

[ypearson]

This worked for me:

#define SEGGER_RTT_MAX_NUM_UP_BUFFERS             (1)
#define SEGGER_RTT_MAX_NUM_DOWN_BUFFERS           (1)
#define BUFFER_SIZE_UP                            (32)
#define BUFFER_SIZE_DOWN                          (16) 
#define SEGGER_RTT_PRINTF_BUFFER_SIZE             (8u)