Green LED Not Working on Homemade Arduboy (Pro Micro)

Anyway, now I am able to load .hex file without any issue (I repeated the procedure, choosing Cathy3K, and so on…and it worked!).

But now I have another issue: the green LED (RGB) doesn’t work. Of course I tested it and it works as component…

I read that it seems a common issue when the green LED doesn’t work, as reported here:

If I use the “@Mr.Blinky’s alternate wiring” when I’ll load the .hex files, will they work or not?

I’m very confused with all the several pin configurations! I still don’t understand a simple thing: if Arduboy is an “open source project”, if I want to create it on my own (DIY), why do I have to modify the pin configurations? I don’t understand it! The original Arduboy uses an ATMEGA32U4 as microcontroller, which is the same there is on Arduino Pro Micro (I’m using), so why do I have to use an “alternative pin configuration” in order to make the green LED working???

Because the Arduboy uses pins on the ATmega32U4 that aren’t brought out to a pad on the Pro Micro. If you used an Arduino Leonardo, which is what the Arduboy was prototyped from, the proper pin for the green LED and others missing on the Pro Micro would be available to you.

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I am not sure if your clone has sound or not but if so, you would have discovered the missing pins on a Pro Micro if you were to set up sound as per the original.

My clone has sound and all .hex files work like a charm!
The only problem is that the green LED does not work.

This is my PIN configuration:

Control Keys:

UP - A0
A - D7
B - D8

OLED Display:

SCL - D15
SDA - D16
DC - D4
RES - D6




RED - D10

How can I fix the issue of green LED in order to make it working?

I see. You have only hooked your speaker up to D5, On the real Arduboy it is connected to two pins and ground giving ‘two’ channels. You cannot do that on the Pro Micro.


As best I understand it, you’d have to change your wiring scheme to the alternate wiring scheme:

(See the rightmost column.)

And then you’d have to recompile all your games with the Homemade Package, with the alternate wiring scheme selected from the appropriate menu.

As @MLXXXp said, the reason you have to use the alternate wiring scheme to get the green LED working is because the Pro Micro does not expose the same pins as the Leonardo, and Arduboy is based on the Leonardo, not the Pro Micro.

The reason you’d have to recompile the games from source is because they’ll be trying to use the proper Arduboy pin layout (i.e. the Leonardo pin layout), and they need to be modified to use the Pro Micro alternate wiring, and that modification requires a recompile.

(As far as I’m aware, nobody has yet devised a way to make the changes without a recompile, assuming that’s possible.)

It seems you can with the alternate wiring, if I’m reading @Mr.Blinky’s table correctly?

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Yes, I think you are correct but I don’t think this one is wired up that way.

@alfioscuderi1978 has wired one of his speaker pins to ground as per the ‘standard wiring’. He also has reset wired the OLED CS to GND and OLED Reset to pin 6 which is part of the ‘standard wiring’.

It means that I couldn’t upload the .hex files (games already compiled for original Arduboy): I’d recompile them, but I’d need of .ino source code. The problem is that often you find .hex and not .ino…

So…I prefer to have the green LED not working, but everything else works great!

Anyway, thank you for your answer!

I am in the same boat as you … I have made a Pro Micro version of an Arduboy. I too have just ignored the green LED.

The Pro Micro is so easy to get your hands on though, its cheap and therefore tempting!

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Ehy, guys! I solved the green LED issue!!!

I just soldered a very small wire directly on atmega32u4 of my Pro Micro, exactly on pin number 12 (Digital Pin 11) and there I connected the resistor and the green LED (as described on original Arduboy schematics)…and BANG!!! It worked! :grinning:

It was not very hard to solder because that pin the first one on a side of atmega (near a corner). Anyway I had to use a very small soldering iron tip.

Here is a picture:

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Nice work … my soldering isn’t that good!

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If you have one of the speaker pins tied to GND then some sounds won’t play with certain .hex files compiled for a real Arduboy. For those sounds to work, speaker pin 2 needs to be connected to ATmega32u4 pin 32 (PC7), which is Arduino pin 13. This pin isn’t brought out on a Pro Micro.

Sounds problems if you tie speaker pin 2 to GND:

  • Only one part of a two part score will play using AruduboyPlaytune.
  • Tones that should play at high volume will only play at normal volume using ArduboyTones.
  • ATMlib sounds will play at lower volume than they should.
  • No tones will play that use the BeepPin2 class of the Arduboy2 library.

Thank you very much!