SlimeVR Tracker firmware for ESP

Firmware for ESP8266 / ESP32 microcontrollers and different IMU sensors to use them as a vive-like trackers in VR.

Requires SlimeVR Server to work with SteamVR and resolve pose. Should be compatible with owoTrack, but is not guaranteed.

Configuration

Firmware configuration is located in the defines.h file. For more information on how to configure your firmware, refer to the Configuring the firmware project section of SlimeVR documentation.

Compatibility

The following IMUs and their corresponding IMU values are supported by the firmware:

BNO085 & BNO086 (IMU_BNO085)
- Using any fusion in internal DMP. Best results with ARVR Stabilized Game Rotation Vector or ARVR Stabilized Rotation Vector if in good magnetic environment.
BNO080 (IMU_BNO080)
- Using any fusion in internal DMP. Doesn't have BNO085's ARVR stabilization, but still gives good results.
MPU-6500 (IMU_MPU6500) & MPU-6050 (IMU_MPU6050)
- Using internal DMP to fuse Gyroscope and Accelerometer. Can drift substantially.
- NOTE: Currently the MPU will auto calibrate when powered on. You must place it on the ground and DO NOT move it until calibration is complete (for a few seconds). LED on the ESP will blink 5 times after calibration is over.
BNO055 (IMU_BNO055)
- Performs much worse than BNO080, despite having the same hardware. Not recommended for use.
MPU-9250 (IMU_MPU9250)
- Using Mahony sensor fusion of Gyroscope, Magnetometer and Accelerometer, requires good magnetic environment.
- See Sensor calibration below for info on calibrating this sensor.
- Specify IMU_MPU6500 in your defines.h to use without magnetometer in 6DoF mode.
- Experimental support!
BMI160 (IMU_BMI160)
- Using Mahony sensor fusion of Gyroscope and Accelerometer
- See Sensor calibration below for info on calibrating this sensor.
- Experimental support!
ICM-20948 (IMU_ICM20948)
- Using fusion in internal DMP for 6Dof or 9DoF, 9DoF mode requires good magnetic environment.
- Comment out USE_6DOF in debug.h for 9DoF mode.
- Experimental support!

Firmware can work with both ESP8266 and ESP32. Please edit defines.h and set your pinout properly according to how you connected the IMU.

Sensor calibration

It is generally recommended to turn trackers on and let them lay down on a flat surface for a few seconds.* This will calibrate them better.

Some trackers require special calibration steps on startup:

MPU-9250, BMI160
- Turn them on with chip facing down. Flip up and put on a surface for a couple of seconds, the LED will light up.
- After a few blinks, the LED will light up again
- Slowly rotate the tracker in an 8-motion facing different directions for about 30 seconds, while LED is blinking
- LED will turn off when calibration is complete
- You don't have to calibrate next time you power it off, calibration values will be saved for the next use

Infos about ESP32-C3 with direct connection to USB

The ESP32-C3 has two ways to connect the serial port. One is directly via the onboard USB CDC or via the onboard UART. When the chip is connected to the USB CDC, the serial port shows as USB Serial Port in Device Manager. The SlimeVR server will currently not connect to this port. If you want to set your WiFi credentials, you can use the PlatformIO serial console. There you have to enter the following: SET WIFI "SSID" "PASSWORD"

Uploading On Linux

Follow the instructions in this link PlatformIO, this should solve any permission denied errors

Contributions

By contributing to this project you are placing all your code under MIT or less restricting licenses, and you certify that the code you have used is compatible with those licenses or is authored by you. If you're doing so on your work time, you certify that your employer is okay with this.

For an explanation on how to contribute, see CONTRIBUTING.md