Firmware for Open Health Band
This repository regroups all the firmware and tests which run on Open Health Band.
For hardware plans and schematics see movuino/OpenHealthBand. For the web BLE GUI see movuino/OpenHealthBandVisualization
All OHB firmware make use of Arduino Integrated Development Environment.
- Open the Arduino IDE
- Navigate to
Preferences - Add
https://movuino.github.io/movuino-board-index/package_movuino_index.jsonas an 'Additional Board Manager URL'.
The following librairies are required to build the firmware and tests:
- MPU9250 by hideakitai : place the version provided in Arduino Librairies
- Adafruit Bluefruit nRF52 : version 0.21.0
- Max86141 : version 1.0.4
Those libraries are all available in the Arduino Library manager except MPU9250 that we should add in Arduino Librairie.
The following services and characteristics use Notification properties :
The Error Characteristic allows to send boolean errors from IMU, PPG. Thus, when error is 0 data is detected else 1.
| ErrorService | ErrorCharacteristic | |
|---|---|---|
| UUID | 0x1200 | 0x1201 |
| 2 bytes | byte 1 | byte 2 |
|---|---|---|
| ErrorCharacteristic | errorIMU | errorPPG86 |
With the IMU Service and characteristics, data from accelerometer, gyrometer and magnetometer can be send by BLE.
| IMUService | AccCharacteristic | GyroCharacteristic | MagCharacteristic | |
|---|---|---|---|---|
| UUID | 0x1101 | 0x1102 | 0x1103 | 0x1104 |
| 11 bytes | 4 bytes (0-3) | 2 bytes (5-6) | 2 bytes (7-8) | 2 bytes (9-10) |
|---|---|---|---|---|
| AccCharacteristic | timestamp | AccX | AccY | AccZ |
| GyroCharacteristic | timestamp | GX | GY | GZ |
| 10 bytes | 4 bytes (0-3) | 2 bytes (4-5) | 2 bytes (6-7) | 2 bytes (8-9) |
|---|---|---|---|---|
| MagCharacteristic | timestamp | MX | MY | MZ |
With the PPG Service and characteristics, data from PPG can be send by BLE. We can have these type of sensor configuartions :
- 1 PD - 2 LEDS
ledSeq1A_PPG1Characteristic1 = characteristic for data taken from photo-diode
| PPG86Service | ledSeq1A_PPG1Characteristic1 | SNR1_2PPG1Characteristic1 | |
|---|---|---|---|
| UUID | 0x1300 | 0x1301 | 0x1315 |
| 20 bytes | 4 bytes (0-3) | 4 bytes (4-7) | 4 bytes (8-11) | 4 bytes (12-15) | 4 bytes (16-19) |
|---|---|---|---|---|---|
| ledSeq1A_PPG1Characteristic1 | timestamp | sample 1 | sample 2 | sample 3 | sample 4 |
| 4 bytes | 4 bytes (0-3) |
|---|---|
| SNR1_2PPG1Characteristic1 | SNR photo-diode 1 |
- 2 PDs - 1 LED
ledSeq1A_PPG1Characteristic2 = characteristic for data taken from photo-diode 1 ledSeq1A_PPG2Characteristic2 = characteristic for data taken from photo-diode 2
| PPG86Service | ledSeq1A_PPG1Characteristic2 | ledSeq1A_PPG2Characteristic2 | SNR1_2PPG1Characteristic2 | SNR2_2PPG2Characteristic2 | |
|---|---|---|---|---|---|
| UUID | 0x1300 | 0x1305 | 0x1307 | 0x1313 | 0x1314 |
| 20 bytes | 4 bytes (0-3) | 4 bytes (4-7) | 4 bytes (8-11) |
|---|---|---|---|
| ledSeq1A_PPG1Characteristic2 | timestamp | sample 1 | sample 2 |
| ledSeq1A_PPG2Characteristic2 | timestamp | sample 1 | sample 2 |
| 4 bytes | 4 bytes (0-3) |
|---|---|
| SNR1_2PPG1Characteristic2 | SNR photo-diode 1 |
| SNR2_2PPG1Characteristic2 | SNR photo-diode 2 |
- 2 PDs - 3 LEDs
ledSeq1A_PPG1Characteristic3 = characteristic for data taken from photo-diode 1 ledSeq1A_PPG2Characteristic3 = characteristic for data taken from photo-diode 2
| PPG86Service | ledSeq1A_PPG1Characteristic3 | ledSeq1A_PPG2Characteristic3 | SNR1_2PPG1Characteristic3 | SNR2_2PPG2Characteristic3 | |
|---|---|---|---|---|---|
| UUID | 0x1300 | 0x1309 | 0x1311 | 0x1317 | 0x1318 |
| 12 bytes | 4 bytes (0-3) | 4 bytes (4-7) | 4 bytes (8-11) |
|---|---|---|---|
| ledSeq1A_PPG1Characteristic3 | timestamp | sample 1 | sample 2 |
| ledSeq1A_PPG2Characteristic3 | timestamp | sample 1 | sample 2 |
| 4 bytes | 4 bytes (0-3) |
|---|---|
| SNR1_2PPG1Characteristic3 | SNR photo-diode 1 |
| SNR2_2PPG1Characteristic3 | SNR photo-diode 2 |
In order to detect the peripheral in the Bluetooth Settings for iPhone, we added the HeartRate taken from Adafruit Bluefruit nrf52 librairies --> Peripheral. However, it is not sent by BLE.
The following service and characteristics use READ and Write properties :
With the Start_Stop Service and characteristics, central BLE can decide when to start or stop data transfert and change leds intensity, sample rate and sample average.
| Start_StopService | StartCharacteristic | intensityLedsCharacteristic | smplRateCharacteristic | smplAvgCharacteristic | |
|---|---|---|---|---|---|
| UUID | 0x1400 | 0x1401 | 0x1402 | 0x1403 | 0x1404 |
| 1 byte | 1 byte (0) |
|---|---|
| StartCharacteristic | 1 (start) or 2 (stop) |
| intensityLedsCharacteristic | leds intensity |
| smplRateCharacteristic | PPG sample rate |
| smplAvgCharacteristic | PPG sample average |
| Values | leds intensity |
|---|---|
| 0 - 255 | leds off (min value) - leds on (max value) |
| Values (integer) | PPG sample rate (Hz) |
|---|---|
| 0 | 25 |
| 1 | 50 |
| 2 | 84 |
| 3 | 100 |
| 4 | 200 |
| 5 | 400 |
| 14 | 128 |
| 15 | 256 |
| 16 | 512 |
| Values (integer) | PPG sample average (Hz) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 | 16 |
| 5 | 32 |
| 6 | 64 |
- Choose your PPG sensor type (PDLEDs, PDsLED or PDsLEDs) by activating the #define
- To read data from PPG, IMU activated the #define from peripheral and central
- To read data on Serial Monitor or send by BLE activate the #define from peripheral
Documentation for the project is available at movuino.github.io/OpenHealthBandFirmware or in the /docs folder.
OHB firmware can integrate with the Open Health Band Visualization project which provide real time monitoring of the OHB sensors in a web browser.