Building Hardware
- Form 2 metres of cabling, I heatshrunk the cables together, you'll need 6 in total.
- Crimp JST-XH plugs onto the cables. I chose to bundle the VCC, GND, SCL, SCA into a 4 pin connector, and the AD0 and INT into a 2 pin connector.
- Solder the cabling onto the IMU, taking care to note down which cable is connected to each pin
- Solder the JST-XH corresponding sockets to your stripboard.
- Solder resistor connectors
- Plug in the IMU cables.
- Solder solid core cabling from the strips connected to each JST-XH socket pin, via resistors if specified, to the following ESP32 pins.
| IMU Pin | ESP32 Pin |
|---|---|
| VCC | 3V3 |
| GND | GND |
| SCL/SCLK | GPIO22 via 4.7 kΩ to 3V3 |
| SDA/SDI | GPIO21 via 4.7 kΩ to 3V3 |
| AD0/SDO | None |
| INT | GPIO19 |
| Soldering in Progress | Fritzing Schematic from /area/pcb/ |
|---|---|
 |
 |
- Connect the battery shield to the ESP32
- Use an SPDT toggle switch if you wish to be able to toggle the power, and conserve charge when not using
- Put the 18650 cell in to the shield
| 18650 Shield | ESP32 Pin |
|---|---|
| 5V | 5V |
| GND | GND |
under (re)construction
- Due to data corruption, the actual sketch has been lost. It drew on this sketch by Kris Winer, that uses open source sensor fusion algorithms to increase the stability and accuracy of the sensor. Adapting the sketch involved removing redundant measurements from the serial print calls. At a later date I may have time to create the sketch again.
- The only data needed from the IMU is the head rotation. This can tested by sending all three rotation values via Serial, rotating your head whilst the sensor is attached to the bone condudction headphones, and selecting the measurement which corresponds with the axis that experiences the largest delta.
- The sketch used the onboard Bluetooth capabilities of the ESP32 to send the serial data via BT.
- Flash the ESP32 via USB (you will require your ESP32's Arduino Library, as well as esptool installed).
- Place circuit inside a wearable pouch - I used a belt pouch for a PDA I found online
- Orient circuit so that USB B Micro on the Battery Shield is accessible for charging.
- Connect the IMU to the bone conduction headphones. I did this via velcro, so that it was somewhat adjustable while using.
