Teensy

Rotary encoders are notoriously difficult to get right.

Although I haven’t used this new encoder class yet, it looks very interesting. From active Teensy forum user Theremingenieur, it allows initialization with upper and/or lower limits.

You can find the code in this thread.

While working on a project to automate environmental control in our greenhouse, I needed to implement a menu interface on a small OLED display. In this sub-project, meant to test the concept, I’ve used a Teensy 3.1, a small I2C-driven 0.96" monochrome OLED display and a rotary encoder.

Bill of materials:

• Teensy 3.1 - the Teensy 3.1 is no longer available, but you can easily find the compatible Teensy 3.2.
• 0.96" yellow/blue I2C OLED module - I used the version with the yellow band at the top so that it this area could act as the highlighted region of the display.
• Rotary encoder with push-button switch - I used this one from Adafruit, but there are many options.
• {% asset_link MC74HC14.pdf 74HC14 Schmitt Trigger inverter %} - to debounce the pushbutton.

Description

This project is a proof-of-concept for using a rotary encoder to manipulate an on-screen menu of options. A number of electronics design concepts are used here.