Hi, people! Newbie here, but enthusiast and eager to learn.
Sometime ago I bought an Arduino Uno R3 clone, with Atmega 328P and the famous CH340G. Uploaded some sketch and everything was working just fine. But last Wednesday my Mac doesn’t recognized anymore the board. Before I go on with the issue, let me say that I checked with:
- MacOS 11.3. Arduino IDE 1.8.13.
- Windows 10 on Lenovo.
- Linux Debian on a Raspberry Pi.
None of them recognized the board. Not even from the terminal.
ioreg -p IOUSB -w0 | sed 's/[^o]*o //; s/@.*$//' | grep -v '^Root.*' doesn’t show anything.
Others peripherals where recognized (like my Kindle or my iPhone). I bought another cable, and neither worked.
After some research, I saw that the CH340G need some drivers to working. But in this case, it’s not a driver issue, since until last month everything works correctly.
Found the schematics for the exactly model that I have here: https://www.terraelectronica.ru/pdf/show?pdf_file=%2Fz%2FDatasheet%2FU%2FUNO_R3%28CH340G%29.pdf
By the way, I found the pinout of the ATmega 328P in Reddit, here: https://i.redd.it/bggdd9srui351.png
And with a multimeter I checked the communications line between the CH340G and the Atmega 328P. Specially this:
- PIN 2 (TXD) to R8 resistor and then to ATmega’s PIN 30.
- PIN 3 (RXD) to R9 resistor and then to ATmega’s PIN 31.
No issues with these lines.
Since when I plug the Arduino to the USB of my Mac, all leds are on, and the last code I uploaded still function (checked), the last thing I inspect are the lines UD - and UD + of the CH340G.
Always with the multimeter set to continuity, I check communication between PIN 5 and 6 and the pads of the USB B conector. Found that PIN 6 (D-) have communication, but PIN 5 (D+) haven’t.
So, my questions are:
Is this the possible the reason because my board is not recognize?
Theoretically, if I strip a wire of an old USB A conector, and solder each cable to each specific connector (PT1 for +5V, GND to any metal on board, and D+ and D- to PINS 5 and 6), it should work, right?
Thanks in advance! And, like I say, I’m newbie, so please bear with me!