ssd1306-on-pico

A small extensible rendering library for SSD1306 OLED display on Raspberry Pi Pico.

This is ported from ssd1306-on-linux repository and tested on Raspberry Pi Pico.

What's included:

1. A simple rendering library to render digits and symbols on SSD1306. [digitRenderer]
2. A Pico I2C wrapper to communicate with SSD1306. [i2cSend]
3. A utility to create new symbols to display on SSD1306. [mapGenerator]
4. A program to display the value of Pico's onboard temperature sensor on SSD1306. [main.c]

Wiring (for Raspberry Pi Pico)

Build and Run the program

The main program main.c uses the digitRenderer library to render digits/symbols on SSD1306 and the i2cSend wrapper to send commands and data to SSD1306. The main loop reads the value of the onboard temperature sensor and displays it to the SSD1306 display.

Steps to build and run the program:

• Setup the Pico SDK on your system if not already done.

• Create a new directory in the same directory as pico-sdk. Let's name it pico-projects.

• Clone this repository to pico-projects directory using git clone https://github.com/bkhajuria/ssd1306-on-pico.git.

• Switch to the directory ssd1306-on-pico.

• Create a new directory named build and switch to it mkdir build && cd build.

• Run cmake ... Build configuration will be done and build files will be written.

• Run make. Upon succesful build, target files ssd1306pico.elf, ssd1306pico.uf2 will be generated.

  TIP: To speed up the build process, use make -j4 or make -j6 depending upon the number of cores available on the system.

• Now flash the Pico by connecting it as a USB mass storage device. To do this, press and hold the BOOTSEL button on Pico, connect it to the system via USB and then release the button. (Checkout the guide).

• Once connected, drag and drop the ssd1306pico.uf2 file to the mass storage device. It will get ejected automatically and the program will start running on Pico.

Adding new Symbols/Characters

New symbols can be created using the mapGenerator utility. Below illustration adds and displays the Raspberry Pi logo:

• In mapGen.c, Add a new 16*16 matrix to the the symbolMap array that represents Raspberry Pi logo.
• Increase the value of NUM_SYMBOLS macro by 1 (since we added one symbol).
• Build by running make in the mapGenerator directory.
• Run the generated executable as ./mapGen.
• It will print the bitmaps for all the digits and symbols.
• Copy the 32-byte bitmap generated for the new symbol.
• Add the bitmap to the symbolMap array in digitRenderer.c. Increase the value of NUM_SYMBOLS macro by 1.
• Add enumeration for the new symbol in digitRenderer.h.
• To test rendering the new symbol use the renderSymbol function.

Resources

• SSD1306 Datasheet
• RP2040 Datasheet
• Getting Started with Pico