94 lines
2.1 KiB
Go
94 lines
2.1 KiB
Go
package microbit
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import (
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"bytes"
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"encoding/binary"
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"gobot.io/x/gobot"
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"gobot.io/x/gobot/platforms/ble"
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)
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// AccelerometerDriver is the Gobot driver for the Microbit's built-in accelerometer
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type AccelerometerDriver struct {
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name string
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connection gobot.Connection
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gobot.Eventer
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}
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type RawAccelerometerData struct {
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X int16
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Y int16
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Z int16
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}
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type AccelerometerData struct {
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X float32
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Y float32
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Z float32
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}
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const (
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// BLE services
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accelerometerService = "e95d0753251d470aa062fa1922dfa9a8"
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// BLE characteristics
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accelerometerCharacteristic = "e95dca4b251d470aa062fa1922dfa9a8"
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// Accelerometer event
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Accelerometer = "accelerometer"
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)
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// NewAccelerometerDriver creates a Microbit AccelerometerDriver
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func NewAccelerometerDriver(a ble.BLEConnector) *AccelerometerDriver {
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n := &AccelerometerDriver{
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name: gobot.DefaultName("Microbit Accelerometer"),
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connection: a,
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Eventer: gobot.NewEventer(),
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}
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n.AddEvent(Accelerometer)
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return n
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}
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// Connection returns the BLE connection
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func (b *AccelerometerDriver) Connection() gobot.Connection { return b.connection }
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// Name returns the Driver Name
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func (b *AccelerometerDriver) Name() string { return b.name }
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// SetName sets the Driver Name
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func (b *AccelerometerDriver) SetName(n string) { b.name = n }
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// adaptor returns BLE adaptor
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func (b *AccelerometerDriver) adaptor() ble.BLEConnector {
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return b.Connection().(ble.BLEConnector)
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}
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// Start tells driver to get ready to do work
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func (b *AccelerometerDriver) Start() (err error) {
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// subscribe to accelerometer notifications
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b.adaptor().Subscribe(accelerometerCharacteristic, func(data []byte, e error) {
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a := &RawAccelerometerData{X: 0, Y: 0, Z: 0}
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buf := bytes.NewBuffer(data)
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binary.Read(buf, binary.LittleEndian, &a.X)
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binary.Read(buf, binary.LittleEndian, &a.Y)
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binary.Read(buf, binary.LittleEndian, &a.Z)
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result := &AccelerometerData{
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X: float32(a.X) / 1000.0,
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Y: float32(a.Y) / 1000.0,
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Z: float32(a.Z) / 1000.0}
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b.Publish(b.Event(Accelerometer), result)
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})
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return
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}
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// Halt stops LED driver (void)
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func (b *AccelerometerDriver) Halt() (err error) {
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return
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}
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