A wireless Arduino-based E-Ink display that helps me navigate through my bike rides.
The display is capable of:
- Showing the current location on the map, which is rotated according to the bearing
- Showing a track on the map
- Showing step-by-step navigation directions from OsmAnd, which was the original purpose of the display, but turned out to be useless
The device receives data from the Android app over the BLE serial.
📒 How it was built
- Arduino Pro Mini – 5V version but the frequency is divided in 4
- 1.54inch e-Paper Module (B) – is not really the suitable option for this use case, it is slow and temperature-dependent. The display is used in the BW mode as BWR full refresh takes 15 seconds
- JDY-23 BLE 5.0 module – should be configured with the STARTEN mode 0 (power on sleep) for power saving
- Li-Po battery
- TP4056 battery charging module
- AMS1117 voltage stabilizer was in the prototype, but turned out to be useless (JDY-23 works fine at Li-Po max voltage)
| Name | Description | Code | Payload | Example |
|---|---|---|---|---|
| Direction | Shows given direction | 0x10 |
1 byte OsmAnd turn type; 4 bytes of unsigned short distance in meters, Little endian | 0x10 0x02 0x04 0x1F 0x00 0x00 – Turn left in 7940 m. |
| Clear | Clears the display | 0x20 |
- | 0x20 |
| Frame prepare | Prepares the display for writing the frame data | 0x30 |
- | 0x30 |
| Frame data | Writes given data to the display memory. Has no log output. Must be called after Frame prepare |
0x31 |
1 byte data size, no more than 62; frame data | 0x31 0x01 0xFF – Writes 1 byte of 8 black dots |
| Frame show | Shows whatever is in the display memory. Must be called after Frame prepare |
0x32 |
- | 0x32 |