HealthyPi with BLE
Building upon its predecessor, HealthyPi v4 brings more flexibility to the user. Powered by the popular ESP32, it opens up wireless and wearable capabilities. Now it’s portable and standalone with in-built rechargeable battery. It can still be used as a HAT for Raspberry Pi or as a standalone wearable platform.
HealthyPi v4 is powered by the ESP32 SoC module, which supports pairing with smartphones through BLE. BLE is widely used in wearable devices because its low power requirements allow it to function for a long time without charging. HealthyPi v4 also supports pairing with other IoT devices for use in mesh networks. BLE 4.2 adds improved security capabilities.
Data measured by Healthy Pi v4 is accessible through standard BLE services for Heart Rate, Pulse Oximeter, Health Thermometer and Battery Service, as well as custom services for ECG and respiration. Notifications are used to transmit data from HealthyPi to the app.
Change the Slide switch from PI mode to WL mode on the healthypi v4 board to switch from V3 mode to BLE mode. The device restarts with an indication, yellow led stays for 2.5sec and the healthypi v4 enter to ble mode with an indication of yellow led blinks until connected. Once it is connected the led will stops blinking and when disconnected the led will starts blinking until connected.
| Service Name | Service UUID | Characteristic UUID |
|---|---|---|
| Heart Rate Service | 0x180D | 0x2A37 |
| Pulse Oximetry Service | 0x1822 | 0x2A5E |
| Health Thermometer Service | 0x1809 | 0x2a6e |
| Battery Service | 0x180F | 0x2a19 |
| ECG Service | 0x1122 | 0x1424 |
| Respiration and Heart Rate variability Service | "cd5c7491-4448-7db8-ae4c-d1da8cba36d0" | "01bfa86f-970f-8d96-d44d-9023c47faddc" |
| Histogram Service | "01bf1525-970f-8d96-d44d-9023c47faddc" |
In the heart rate variability service two Characteristics are included, one for heart rate variability and the other for histogram.
In the ECG service, the default plot is ECG and an option is given to switch from ECG to PPG by writing “spo2” text data.
Introducing the HealthyPi app
Monitoring the human physiological data associated with day-to-day activities becomes much simpler with the HealthyPi app, which is available in app stores, for both Android and iOS devices.
The HealthyPi app is used to communicate directly with HealthyPi v4 hardware, through the same BLE services mentioned above, and can display all vital signs on a single screen.
HealthyPi v4 is a powerful tool, and the HealthyPi app opens up new possibilities for using it to monitor vital signs outside of traditional settings. Among other features, it is capable of displaying respiration, Histogram, Heart rate variability and ECG data.