Show current Solana Slot on OLED Display using Raspberry Pi

This example shows how you can use a Raspberry Pi to display the current Solana slot on an OLED display.

Bill of Materials

• Raspberry Pi 5, 4 or zero
• OLED Display I2C - SSD1306 (For example: https://www.amazon.de/dp/B01L9GC470)

Connect the OLED Display

First you need to enable I2C on the Raspberry Pi:

ssh yourUsername@raspberrypi.local
sudo raspi-config

Select 5 Interfacing Options and then I2C and then Yes to enable it.

Connect the OLED Display to the Raspberry Pi using the following pins:

• VCC to 3.3V (pin 1)
• GND to GND (any ground pin will work. For example pin6 or pin9)
• SDA to GPIO 2 (pin 3)
• SCL to GPIO 3 (pin 5)

Make sure it works using:

sudo i2cdetect -y 1

That should show the address 0x3c for the OLED Display somewhere in the list.

Run the code

Copy the files to your Raspberry Pi. Easiest is to use Cursor or VSCode with the Remote - SSH extension. See the LED example for more details on the raspberry pi setup and a Video Walkthrough.

Or use spc for copying the files (running on your machine):

scp hello-solana.js solana-slot.js package.json package-lock.json jonas@raspberrypi.local:~/Documents/

Install node

Running on the Raspberry Pi:

npm install oled-i2c-bus i2c-bus oled-font-5x7 @solana/web3.js

sudo node solana-slot.js

This should not turn on the display and show the current slot.

Congratulations! You have now a Solana Slot Display! Since this is just JS code you can also use it in all the other examples to show additional info. For example the price for a drink in the bar example or the progress bar for how long the Fan of the air blower will still run. Just experiment and have fun!