Pixl.js & MDBT42Q serial requires TX pin

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  • Hi!

    Looks like the serial.setup() on these boards requires the RX and the TX pin. On STM32 I could get away with only specifying the RX pin. For example on MDBT42Q:

    >Serial1.setup(9600, {rx:D8})
    ERROR: Invalid RX or TX pins

    Is this some Nordic-thing, that can't be changed easily? I have enough pins, so no problem, just curious...

    Flashed the latest cutting-edge build to the MDBT, but sw serial is much worse than the Wifi. (PMS7003 and it's 32 byte packets) I guess bluetooth connection doesn't help :(

  • Argh, yes - looks like that wasn't catered for on the nRF52 port (the nRF52 can handle it fine though). I've just added it and it should make its way into builds today sometime (I'm trying to get a 2v02 release out today so I probably won't commit until I have everything ready to go).

    Shame about the software serial - I guess you might find it works better when you have a connection if you force a lower connection interval with http://www.espruino.com/Reference#l_NRF_­setConnectionInterval but it's still unlikely to be perfect :(

  • Just to add - it's actually quite a handy thing to be able to do. USART RX requires a decent amount of power (1mA or so?) as the oscillator has to stay on - but you can enable just the TX pin and so can transmit on the USART without sapping power.

  • Thanks Gordon!
    Just in time for 2v02 with single pin Serial :)
    Slowing Bluetooth interval to 600ms, Serial works OK, and there is still a slight chance to interact with the Pixl :)
    Haven't counted up, but that way doesn't feel much worse than STM32 soft serial. At least on a smallish test code.

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Pixl.js & MDBT42Q serial requires TX pin

Posted by Avatar for AkosLukacs @AkosLukacs