Documentation
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Overview ¶
This example scans and then connects to a specific Bluetooth peripheral that can provide the Heart Rate Service (HRS).
Once connected, it subscribes to notifications for the data value, and displays it. The Heart Rate Measurement characteristic is a variable-length structure (array) containing a Flags field, a Heart Rate Measurement Value field and, based on the contents of the Flags field, may contain additional fields such as Energy Expended or RR-Interval. More info can be found here: https://www.bluetooth.com/specifications/specs/gatt-specification-supplement-6/ In this example only the heart rate is used, this is the second element in the array of bytes.
To run this on a desktop system:
go run ./examples/heartrate-monitor EE:74:7D:C9:2A:68
To run this on a microcontroller, change the constant value in the file "mcu.go" to set the MAC address of the device you want to discover. Then, flash to the microcontroller board like this:
tinygo flash -o circuitplay-bluefruit ./examples/heartrate-monitor
Once the program is flashed to the board, connect to the USB port via serial to view the output.
Source Files