SSD1306 OLED Example using MicroZig

A small MicroZig example for driving an SSD1306 OLED display with a Raspberry Pico (RP2040).

So my question was: "How to draw a pixel on the screen?"

This example demonstrates that by displaying a picture.

I also included my own FrameBuffer implementation, which I used to learn how the SSD1306 framebuffer and page layout work. There are two common ways to pack 1-bit pixels into bytes: horizontal bit packing and vertical bit packing. The SSD1306 uses vertical bit packing, where one byte represents 8 vertical pixels within a page. My FrameBuffer implementation supports both, but it is mainly included for learing purposes.

Hardware

• Breadboard
• Raspberry Pi Pico (RP2040)
• SSD1306 OLED display

Wiring

• OLED SDA -> GPIO19
• OLED SCL -> GPIO20
• OLED VCC -> 3V3
• OLED Gnd -> Gnd

Requirements

• Zig - lastest main version
• picocom for serial logging

You could also use Nix to setup your dev environment:

nix develop

Build and Flash

zig build

Flash the generated UF2 file:

./zig-out/firmware/ssd1306-example.uf2

Serial Logging using Raspberry Pi Debug Probe

Requires picocom.

• Connect Debug Probe U:
  • yellow (RX) → Pico GPIO0 (TX)
  • black (GND) → Pico GND
• Find port: ls /dev/cu.usbmodem*
• Open: picocom -b 115200 /dev/cu.usbmodem*; the device name may differ
• Open in Neovim: :terminal picocom -b 115200 /dev/cu.usbmodem141402
• Exit: Ctrl-A, Ctrl-X