Summary

• 1.3" monochrome OLED
• 3 push buttons, one illuminated by dual LEDs
• Rotary encoder with push-button
• Piezo sounder
• Onboard control chip for autonomous operation
• I²C accessed
• Open-drain INT output
• 3.3V or 5V operation
• New QWIIC / Stemma QT connector
• New optional pull-up resistors on board

What is it?

This handy module combines an OLED display and some buttons in a convenient layout for using as a control panel on the front of a project enclosure. The 128x64 pixel display allows the project to display information to the user, and accept commands and control by means of several buttons. Two small tactile switches are mounted below the display, and could be used as soft-function keys with suitable labels on the display. A rotary encoder sits to the side, allowing values to be adjusted or selections to be made. A larger control button with two illumination LEDs adds a "one-touch" control button which could be useful for activating the main function of the project. On the back is a piezo sounder capable of emitting beeping tones.

Both display and input control chips are accessed via I²C, requiring just four wires in total (power, ground, SDA, SCL) to connect to the main logic board of the project with the MCU. The OLED is an SH1106 module whose address is 0x3C. The buttons, rotary encoder and piezo sounder are accessed via a control chip whose address is 0x3D.

The INT signal from the control chip is provided as well, so that the MCU can read button or wheel events by interrupt. This brings the wire count up to five, but removes the need for the host MCU to poll the chip regularly for events. As the INT line is open-drain, it can be shared with other peripherals to reduce pin count on the host MCU.

A final sixth signal is RESET. Leave this unconnected for normal operation, or apply a short low pulse to reset the controller and the OLED display. This signal is also used for control chip firmware upload, if required.

The power pin is labelled "5V", but the board can run at 3.3V also. However, it is not recommended to power at 3.3V while using 5V logic signals, nor vice versa.

Additionally, the control chip makes four GPIO lines available on a second header, along with power and ground connections, in case of attaching other buttons or indicators. These can be arbitrarily set as inputs or outputs, offering extra digital IO with change detection.

For full details of operation of the I²C slave chip controlling the rotary encoder, piezo sounder and GPIO lines, see the "Data Sheet" link below.

The control chip is an MCU pre-programmed with driver firmware. Please use the "Contact Me" button for feature requests, bug reports, clarifications, or other communications about this.

Why did you make it?

This panel is intended for use on a variety of custom-made test equipment, offering a standard front-panel layout of controls. By making a standard board with a standard layout, a more consistent look can be achieved, and things like drilling patterns and MCU code can be reused across them.

This is an updated version of the OLED-1106 Front Panel Module, using a dedicated onboard controller to drive the buttons, rotary encoder, LEDs and piezo buzzer.

What makes it special?

There are a number of OLED breakout boards available, but few of them manage to combine buttons and display in the same place. In particular, getting the two soft-function buttons up close to the OLED glass so they align with some text labels displayed there is often difficult to achieve with the standard modules, because they have extra board space around the OLED glass. Additionally, the controller chip on this board offloads the slightly tricky task of reading the quadrature encoding of a rotary encoder, emitting a simple stream of events for the host MCU to use directly.

Similar Products

• OLED-mini Front Panel Module A smaller version of this board, containing a 0.96" display and rotary encoder but without the lower row of push-buttons