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Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@the1laz
I flashed the espruino_1v97.99_nrf52832.hex travis build to an MDBT42Q module to give it a spin but couldn't connect via serial. I can connect to it via BLE but serial just wasn't working. I found the notes about it needing to see 3.3V on D8 so I checked it out and found that my CH340G (clone?) only had about 1.7V on RXD. I grabbed another USB-serial module, this time a PL2303HX (clone?) and found only about 0.6V on RXD. Finally tried a CP2102 (clone?) and it worked fine with 3.3V on RXD in idle.
My reference devices are all off aliexpress and not necessarily reliable adherers to good UART practices, but detecting full voltage on that pin might not be a good indicator of when a serial connection is there. Maybe checking for >0.5V using the ADC would be more reliable? I imagine this would affect a puck-js as well, I can't test on mine because I've got the pins already soldered to something.