audiophyl / heltec_tinkering

Setup information and examples for using HelTec's WiFi Kit 32 V3 with the Arduino IDE.

HelTec WiFi Kit 32 V3 in Arduino IDE

Welcome! This is a summary of my findings while setting up the aforementioned HelTec ESP32 microcontroller. Heltec's documentation was lacking, so I hope someone finds these notes helpful.

Process

1. Install Arduino IDE.
2. Add Arduino ESP32 support through File -> Preferences -> Additional Board Manager URLs
   • HelTec's documentation says otherwise, but I found the Espressif arduino-esp32 URL to be best.
   • This URL is https://espressif.github.io/arduino-esp32/package_esp32_index.json
3. Add Espressif ESP32 board support.
   • Tools -> Board -> Board Manager
   • Search for 'ESP32'
   • Select the Espressif package to install
4. Add Acrobotic SSD1306 display support
   • Tools -> Manage Libraries
   • Search for 'U8g2'
   • Select the U8g2 package to install
5. Configure Arduino to use the HelTec WiFi Kit 32 V3
   • Select 'HelTec WiFi Kit 32(V3)' from the Tools -> Board -> ESP32 Arduino menu
   • Connect the board
   • Select the correct port for your setup

Fix an Espressif error

For v2.0.14 and all versions prior of arduino-esp32 from Espressif, a folder will need to be renamed so you can compile sketches. For my setup, that required renaming this folder:

~/snap/arduino/current/.arduino15/packages/esp32/hardware/esp32/2.0.14/variants/heltec_wifi_kit_32_v3

to this:

~/snap/arduino/current/.arduino15/packages/esp32/hardware/esp32/2.0.14/variants/heltec_wifi_kit_32_V3

Following this change, it should now be possible to compile sketches for this board using the Arduino IDE.

Hardware Notes

Display

I find U8g2 (and U8x8) to be the most straightforward to use. Your setup line will depend on correct pin numbering to be passed to the constructor:

OLED_SDA = 17
OLED_SCL = 18
OLED_RST = 21

So your constructor for U8g2 might look like this:

#include <U8g2lib.h>
// set up display for heltec_wifi_kit_32_v3
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ 21, /* clock=*/ 18, /* data=*/ 17);

Links

-HelTec product page
-Hackaday article regarding a similar board
-Robotzero.one blog entry regarding a similar board
-GitHub repository for some HelTec code