A genuine Credit Card Arduboy

My homemade credit card size Arduboy with flash cart has broken. I decided to take it apart and make a new one using the same parts.
Here we are, an Arduboy built on a genuine credit card.
I used three variable resistors (10K), one for volume control, one for left paddle, one for right paddle (for wo player games like Pong).

I have learnt from this forum that the serial flash may be able to run at 4.2V, so I do away with the voltage level shifters and mounted a small daughter board with the serial flash onto the 5V Pro Micro ATMega32u4 board.
I have removed the voltage converter on-board, and feed the 5V from the USB port (form the RAW pin on the pro Micro) to a LIPO battery charger board that I got. Then feed the 4.2V supplied from the charger board to the VCC pin of the Pro Micro.

To my astonishment , everything works fine with the Pro Micro and the Serial Flash that I have already loaded with the firmware for serial flash and 60+ games.

I have yet to test uploading the game binaries and burning MR.Blinky’s latest version of homemade firmware for flash cart.

Here is the demo video https://youtu.be/lke5r84xj-M

and my GitHub for the schematics.



That, is some wiring!


Completed the testing to burn the latest homemade package from @Mr.Blinky using 5V USBAsp programmer.
Then uploaded an 60+ games and the BadApple animation to the serial flash.
The serial flash seems to work ok at 4.2V.
Upload time is also normal, 100 sec, instead of the 200 sec I tested when using a 3.3V Pro Micro with the serial flash to avoid the voltage level shifter.

Here is the part 2 video