Shared Projects

Arduino Nano Breakout Board

A second version which just adds a footprint for a momentary pushbutton.

LM386 BTL Amplifier The BTL AMP imporve PSRR and SNR. Since it drives the speaker without output capacitors, low frequency response is better than OTL.

https://github.com/profdc9/Apple2Card This is an Apple II SD card interface. Details found here:

Sonic 3 FeRAM Adapter adapts an FM-1208S-200SC to the pinout of an FM-1208S-CC

Uses 4 APEM MJTP1230 6x6mm tactile buttons with 2 legs bent and 2 legs snipped to create a 4 way navigation switch used in joysticks.

3d project files can be found on Printables @ https://www.printables.com/model/142497-joystick-hat-switch

DIY option to add LED indication under guitar pedal footswitch pedal washer. Drill 15mm holes for footswitch, put LED ring inside enslosure where lock washer would normally go, add thin clear vinyl washer for insulation; LEDs should shine through white nylon washer on top.

DIY option to add LED indication under guitar pedal footswitch pedal washer. Drill 15mm holes for footswitch, put LED ring inside enslosure where lock washer would normally go, add thin clear vinyl washer for insulation; LEDs should shine through white nylon washer on top. Order on Flex to get LED Indicator ring with flexible lead extensions–trim to your needs. Eliminates running wires through enclosure space to power LEDs. (Prototype, Unverified).

Introduction

This is a power regulator board for my MGBC (Pocket Color) project. This should work perfectly fine on a regular Game Boy Color or Pocket, but I haven’t exhaustively tested it.

Disclaimer

Please keep in mind, I haven’t fully tested this power board, so you accept any and all risks associated with using this board. That being said, it’s similar to a lot of other replacement Game Boy power supplies out there, with a few distinct differences.

Features

Some features of this power board include:

• Changing the power switch to a “soft power switch,” meaning the main power of the Game Boy does not flow through the switch
• Improved efficiency over the OEM regulator
• Improves the audio output of the Game Boy
• Bootloop protection circuitry to prevent overdischarge of AAA batteries, and to allow the Game Boy to die gracefully instead of violently stuttering until the regulator gives up

Using with a GBC or MGB

If you wish to use this on a GBC/MGB, you must:

• Remove U5 from the Game Boy circuit board (the DC/DC converter board) and replace it with this one. Make sure you have a header pin populated for pin 2 on the socket!
• On the main Game Boy PCB, add a wire from pin 2 of the U5 socket to the node labelled SW1-VCC. This node connects to the power switch and F1, so you can choose either points.
• If you are soldering a wire to the fuse directly, MAKE SURE YOU CHOOSE THE CORRECT SIDE. It must be the side that’s directly connected to the power switch. A multimeter will not tell you which side of the fuse is which if you have the fuse on the board.

Also note this will only work with IPS modded systems. There are no LCD power rails.

Bill of Materials

The AD5293 Digital Potentiometer is an SPI, 100K-ohm device. The potentiometer sports 1024 resistance steps. The digital logic power requires 2.7v to 5.5v. The potentiometer circuit operates with dual analog supply voltages from +/-9v to +/-16.5v. The pins act similarly to a passive resistive potentiometer, but require that voltages placed on any of the three pins not exceed the analog power supply voltages.

The Cedar Grove AD5293 custom breakout board provides power and signal connections for SPI and the potentiometer chip. The AD5293 is also used in the AD9833-based Cedar Grove Precision VCO Eurorack module. A CircuitPython driver is available: https://github.com/CedarGroveStudios/CircuitPython_AD5293