This Simple Add-On (SAO) features a 128x128 grayscale OLED screen, a built-in three-axis accelerometer and two analog pots. The obvious application is to recreate the iconic Etch-A-Sketch experience, but you can do much more than that! How about a game of pong or snake with the built-in analog controllers?

Let your creativity loose and see what you can come up with. Scroll to the bottom of the page for Demo Video.

MICROCONTROLLER NOT INCLUDED - OPTIONAL

This SAO does not have a built-in microcontroller. You have to provide an MCU with control code to interface with the I2C port on the SAO connector. The OLED (SSD1327 controller on 0x3C/3D) and accelerometer (LIS3DH on 0x18/19) both share the I2C bus. The analog pots are wired to ADC inputs on the accelerometer AND the GPIO1/2 pins of the SAO socket.

If you'd like a microcontroller to operate the Etch sAo Sketch stand-alone, add the option of the SAO Demo Controller. With that option selected the SAO Demo Controller will be pre-loaded with demo firmware for the Etch sAo Sketch. The SAO Demo Controller is also available separately in my Tindie store here for general SAO use too.

AVAILABLE NOW AS PRE-ASSEMBLED ONLY

As of June 2025, I've decided to sell these pre-assembled. They were previously listed as kits, but I want to ensure quality by fully testing them and avoid risk of damage to the OLED screen in shipping.

IMPORTANT NOTE ABOUT I2C HOST COMPATIBILITY

Some combinations of MCU/Board/SAO work fine, others require slow (software) I2C to accommodate excessive pull-up resistance. Please remove the I2C Pull-up resistors (V1.0 R30/R31, V1.1 through 1.3 R1/R2) before assembly. This applies to all versions through V1.3. It is much easier to remove the excessive pull-up resistance on the red board prior to assembly! Learn more here.

IMPORTANT NOTE ABOUT ANALOG POT TRAVEL IN I2C MODE

V1.0.X : The analog pots have a reduced range of travel when used with the built-in accelerometer ADC inputs, AKA I2C Mode. The preferred method to access the full range of travel is to use the SAO GPIO 1&2 pins as analog inputs to your host microcontroller. If you received the SAO Demo Controller with your Etch sAo Sketch V1.0.X, it is already configured this way with the appropriate solder jumper closed.

V1.1.X+ : The analog pots have the full range of travel available through the ADC inputs of the Accelerometer (I2C Mode) and the ADC lines available at the SAO GPIO positions.

HARDWARE VERSION TABLE

KIT VERSION NOTES

If you received a kit version of the Etch sAo Sketch, the surface mount components are installed, but you get to enjoy closing a few solder jumpers, mounting the screen to the back of the red board with copper alignment spheres, and soldering in the potentiometers and SAO header. The final step is to snap on the included white knobs over the pots. Build instructions are available here.

BULK ORDERS AND CONVENTIONS

I am happy to offer a bulk discount if you want to use this SAO at your convention or festival. Please contact me through Tindie's messaging feature to inquire and discuss logistics and lead-time.