JLink RTT Viewer Wont Log

RE: JLink RTT Viewer Wont Log

Krzysztof Zaraska — Wed, 04 Oct 2017 22:58:56 GMT

It's safe as in it won't hurt the chip. As for the RTT Viewer, I've seen it hang/crash randomly so I wouldn't trust it with my life...
By the way please take time to read chapter 13 of the J-Link user manual which describes RTT. There are some pitfalls regaring locking and buffering you should be aware of (section 13.4.2.2.).

RE: JLink RTT Viewer Wont Log

zoltan — Wed, 04 Oct 2017 18:48:19 GMT

A 10ms delay between the flush and the reset did the trick! Thanks! As a side note, I don't see a function to de-initialize the logs before a reset. Is it safe to keep initializing the logs after every reset without de-initializing somehow?

RE: JLink RTT Viewer Wont Log

Krzysztof Zaraska — Wed, 04 Oct 2017 17:50:35 GMT

sd_power_system_off() should not return, and the CPU wakeup should cause a reset. HOWEVER, if you have debugger (RTT) connected, then sd_power_system_off() returns an error. In other words, you cannot put the device to sleep if RTT is connected. Sorry :)

devzone.nordicsemi.com/.../

Try putting a delay between NRF_LOG_FINAL_FLUSH() and SystemReset(). Basically, RTT uses a ring buffer, and the client tracks CPU writes. If CPU resets before the client reads all data (thus returning the buffer to the default state) then the client reads stuff from the wrong place.
NRF_LOG uses internal buffering. Try calling SEGGER_RTT_Write() and friends directly and see what happens (when calling these, BufferIndex should be 0).