esp32-hid-joystick

This is a Bluetooth Low Energy (BLE) HID joystick I put together using a WEMOS D32PRO and an Adafruit joystick.

Why?

The aim of this project is build a functional, cheap and open Joystick/Gamepad device using off the shelf parts, which is battery powered and connects to any PC/Mac/Phone using BLE.

This project currently uses ESP32 micro controller because:

1. It is cheap and widely available.
2. It has an open source SDK which is based on FreeRTOS.
3. Has great out of the box examples of BLE HID devices, which I used as the basis for this project.
4. All the peripherals I needed to make magic happen.

How?

The core of this software is its HID report, and esp_hidd_send_joystick_value which transmits the current state of the joystick.

To read the analogue joystick x and y values I am using the adc driver.

Building

This project uses esp-idf and requires a recent version with support for CMake.

Usage

The below image shows this joystick detected by chrome after being paired.

Handy gamepad tester used is located at http://luser.github.io/gamepadtest/

Assembly

TODO Circuit diagram.

J1 connector.

P6 3v3 P5 Sw01 GPIO_14 P4 Sw02 GPIO_25 P3 Sw03 GPIO_26 P2 Sw04 GPIO_27 P1 GND

J2 connector

P1 Sw10 GPIO_19 P2 Sw09 GPIO_18 P3 Sw08 GPIO_17 P4 Sw07 GPIO_16 P5 Sw06 GPIO_05 P6 Sw05 GPIO_04

LEFT_X GPIO_32 LEFT_Y GPIO_33 RIGHT_X GPIO_34 RIGHT_Y GPIO_35

TODO

• Make a simple case and wire up a 1S battery
• Cleanup demo code once I have done some integration testing.
• Extend it to add a screen, this requires more HID stuff which is challenging.
• Add add an identify option using an RGB LED so the user knows which is theirs. There is already an LED setup in the HID code.

Dependencies

• https://github.com/craftmetrics/esp32-button

References

• https://eleccelerator.com/tutorial-about-usb-hid-report-descriptors/
• https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf

License

This project is copyright Mark Wolfe and Espressif Systems (Shanghai) PTE LTD and is released under Apache 2.0 license.