Arduino Uno R4 Wifi RA4M1 USB bypass by soldering USB bridge pads

Official Hardware UNO Family UNO R4 WiFi
1

I soldered the USB bridge pads (RA4M1 USB) to program the RA4M1. However, the arduino completely does not show up when I connected it to my computer. May I know what should I do to make it work? Thanks for helping.

2

Welcome to the forum

Why do you want to do this ?

3

This might help https://docs.arduino.cc/tutorials/uno-r4-wifi/cheat-sheet/#usb-bridge

4

A while ago, when I was playing with the Arduino UNO Wifi (and Minima), I experimented
with a setup like this. However instead of soldering the connection I soldered a switch
across it.

At the time I created a Variant of the WiFi, to setup to use the Native USB on the
RA4M1, which is similar at that point to the Minima.

There are a few threads on it, including:

I personally preferred running in that mode, as USB is faster. Does not require the board to copy the USB data over a non-fifo UART to/from the ESP32, which then did the USB transfer.

It also allowed the more complete Serial USB interface to work... Not sure if I still have that
variant sitting around here... Most likely way out of date

Good luck

5

Hi if you have soldered the USB bridge pad , ground MD pin (1st unmarked pin next to IOREF) and connect USB cable and you should see Arduino come up in IDE. This is bootloader mode.

6

Hi, thanks for helping. I have tried connecting the pin next to IOREF pin to the GND pin but it didn't shows up when I connected with USB cable.

7

Thanks for helping out. I will try to do it, but not sure if I can do it correctly as I'm just a beginner

8

Hi @jinyuan219. Please answer @UKHeliBob's question:

9

My Arduino board seems not working with the esp32 because it shows as Device Description Failed at my device manager when I connected to my computer. I tried many ways but can't still resolve the issue. So I decided to try connecting the USB directly to the RA4M1.