Hardware Setup

Raspberry Pi Zero Connections

Device	Device Pin	GPIO Pin	Description
OLED	SDA	SDA	The project is tested with both SSD1306 and SH1106 oled displays
	SCL	SCL
Fuel Gauge	SDA	SDA (Pulled Up)	Used for detect remain battery life by using MAX1704 Chipset. This is optional and can be disables in the config.py
	SCL	SCL (Pulled Up)
MIDI IN		RX	Needs a 6N138 chip to normalize input voltage.
MIDI Out		TX	Raspiberry pi is 3.3V out. Midi requires 5V out. 7414 double inverter circuit is required
Up Button	GND	GPIO 17	Software pulled up. Grounded is on.
Down Button	GND	GPIO 22	Software pulled up. Grounded is on.
Left Button	GND	GPIO 27	Software pulled up. Grounded is on.
Right Button	GND	GPIO 23	Software pulled up. Grounded is on.
Center Button	GND	GPIO 23	Software pulled up. Grounded is on.
Enter Button (A)	GND	GPIO 5	Software pulled up. Grounded is on.
ReturnButton (B)	GND	GPIO 6	Software pulled up. Grounded is on.

OLED and Fuel Gauge setting Configuration

This project is tested on both SSD 1306 and SH1106 OLED displays. By default the address is set to 0x3c and can be modified in GPIO_Init.py

displayConfig = {
    "DisplayType": "SH1106", # Or SSD1306
    "Rotation": 2,  # 0:0, 1:90, 2:180, 3:270
    "port": 1, #i2c port
    "address": 0x3c
}

Fuel gauge i2c address can be modified under config.py file

batteryConfig = {
    "enable": True,
    "UPS_Method": "MAX1704",  # RaspiUPS or ADS1115 or MAX1704
    "Address": 0x76
}

Don't know what is the device's i2c address?

You can run the following command in the terminal to get the OLED's I2C address.

sudo apt-get install -y python-smbus
sudo apt-get install -y i2c-tools

Once installation is complete then run to get current connected address

sudo i2cdetect -y 1

or you can follow this guide by adafruit: Adafruit 128x64 OLED Bonnet for Raspberry Pi
The address of the MAX1704 can also be detected if connected.