ERRORSRC 0x1 on UART handler

[Victor Nascimento]

Hello,

On my custom board, I'm receiving chunks of UART data, without flow control, at 115200bps. Sometimes (its quite frequent now... sometimes after 10 chunks, sometimes after 100 chunks), im getting ERRORSRC 1 on APP_ERROR_HANDLER(p_event->data.error_communication); line.

My board doesn't include a 32kHz oscillator, and Im using NRF_CLOCK_LFCLKSRC_RC_250_PPM_250MS_CALIBRATION as my clock source (I don't care about current consumption). I'm also using SDK 8 with SoftDevice 8.0.0.

What would cause this? Any idea how to solve it?

edit Edited title so it makes more clear. Thanks @RK

[RK]

No you're not getting that error. That field in the event structure doesn't return an NRF_ERROR_* code (look in the documentation or just read the code), it returns the raw error from ERRORSRC in the UART.

If you then look at the nRF52 series documentation for ERRORSRC you'll see '1', which is the error code you're getting, is an overrun error, which, since you're trying to do no-flow-control at 115,200 is not very surprising.

You can probably run at that baud rate without flow control if the chip's not doing anything else, I'm going to guess you're trying it whilst using the softdevice and that's not going to work.

[RK]

Nothing else is likely to cause it - you're doing something which is guaranteed to break. Perhaps you made one small change somewhere which altered the connection interval or some other thing just enough to ruin a lucky rhythm you had going. If your transmissions kept exactly missing radio events and got into a pattern before, it might have worked for a while, but BTLE is random enough it will always break at some point.

This is why flow control exists. Your easiest answer is to use it, then it will work, all the time, every time, no matter what, and almost every UART implementation supports it. Your other option is to look into the multiprotocol timeslot api and request slots to send your data. 15ms would be enough for one packet. You will get them when the softdevice chooses to give them to you, but you will get them, that may be enough.