Using Wio-E5 mini with external UART

Hi, I’m facing a problem trying to use Wio-E5 mini with an external UART interface. Every is working using AT commands with the type C. However, if I use and external 3.3v UART device (like and Arduino board or an FTDI serial converter) it doesn’t work. I supply the board through the 5V pin, putting all GND in common by the device. I verified all voltages on test point (like 3.3V output) and they work. However, i can’t see any response from the device. I use the RX and the TX pin. Any ideas? Thanks

It may work if you supply 5V from the PowerInput (3.7-5V) connector instead of the 5V pin.

if it works with USB cable power and not otherwise it is a problem with your power wires… or the code has a while !serial in the code which haults until the serial monitor connects

@msfujino Thanks for the advice. I find out that it’s working using the ± pin and not the +5V pin. However, looking at the schematic, I’m not sure why it doesn’t works using +5V pin.
Thanks

If you feed power from the 5V pin, U4_CP2102N will also be powered, and if you feed power from the ± pin, U4 will not be powered.
The output pins TX0 and RX0 of U4 are competing with the RX and TX pins you are trying to use.