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  • Background: I'm trying to transfer a stringified JSON object between two Picos (using Serial1, tx:B6, rx:B7 on each, shared GND, console shunted to USB, etc). It works for a couple of KB of data, but beyond a certain size of object the transfer appears to simply fail, leaving the sending Pico in an unresponsive state until it's power-cycled.

    I'm guessing that there's some sort of internal buffer on the Serial port for when JS code delivers data faster than it can be transmitted, but I'm having trouble finding any information on how big it is, or strategies for robustly working around this issue (eg, chunking the data and sending a chunk at a time using setTimout/setInterval is an obvious possibility, but how quickly/slowly should I queue each new chunk up, and/or how do I know when the previous chunk has finished transmitting)?

    Also, does anyone have any information on which baud rates the Pico supports for Serial connections? I'm experimenting to ease the problem by selecting higher baud rates to reduce the chance of buffer overrun, but it's a slow process when you have to connect/disconnect and re-flash two different Picos for every test...

    Basically is there anywhere I can look in more detail regarding the USART specs on the Pico? I've even tried digging into the Espruino source code on Github, but I couldn't find any info there either.


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