MicroPython Forum (Archive)

uPyLoader fails to connect on a LoLin NodeMCU board by wifi or usb cable to PC if RXDO (GPIO3) is attached to modem TX, regardless of modem on/off. [TXD0 (GPIO1) and GND are attached to modem RX and GND respectively.]

uPyLoader connects without problems by usb or wifi if RXD2 (GPIO13), TXD2 (GPIO15) and GND are attached to modem TX, RX and GND respectively.

I need to read modem uart. Is there a way to connect modem to RXD0 or do I need to use different uart serial channels and uos.dupterm? If so how?

Edit: I'll think more about Feedback on uart_swap implementation.

Hmm:
Terminal redirection and duplication
class UART – duplex serial communication bus, methods
Documentation is [s]certainly terse, could use some example code[/s] bloody useless.

this happens because the micro usb is connected to these pins (RXD0 and TXD0) and you can only connect a single device or upyloader or the modem

I think you should be able to connect with upyloader via wifi and with the modem via RXD0 and TXD0