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Setting up Arduino IDE with Heltec ESP32 module for macOS

Heltec WiFi Kit 32 ESP32 module

The Heltec WIFI Kit 32 is an interesting little module that integrates a WiFi/MCU SoC and a small OLED display on a single board. If you want to set up the Arduino IDE to work with this device and you’re on macOS, this is for you. This particular ESP32 module has a number of impressive features: 240 MHz processor speed and 4 MB of flash memory. The onboard OLED display can be conveniently used for debugging.

Implementing a simple menu interface on OLED display

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.