Broadcast the sensor value on Eddystone (BLE) on micro:bit

broadcast-value-on-eddystone-on-microbit.js

const NAMESPACE = [  // sha1('your.doma.in').slice(0, 10)
  0x8f, 0xa3, 0xfa, 0xa1,
  0xb4, 0xa3, 0x99, 0x67,
  0x0c, 0x0f
]
const DEVICE = 0x0000      // 2 bytes
const POWER = 7            // no reason
const CONNECTABLE = false  // no reason

// Returns depend on the role of the device
function getCurrentNumber() {
  return input.acceleration(Dimension.Strength)
  // return input.temperature()
}

function peekIcon(icon: number) {
  basic.showIcon(icon)
  basic.pause(1000)
  basic.clearScreen()
}

// Show an icon at startup
peekIcon(IconNames.Heart)

// Show an icon when the A button is pressed
input.onButtonPressed(Button.A, () => peekIcon(IconNames.Heart))

// Show value when the B button is pressed
input.onButtonPressed(Button.B, () => basic.showNumber(getCurrentNumber()))

// Broadcasting
basic.forever(() => {
  const buffer = pins.createBuffer(16)
  NAMESPACE.forEach((byte, i) => buffer.setNumber(NumberFormat.UInt8BE, i, byte))
  buffer.setNumber(NumberFormat.UInt16BE, 10, DEVICE)
  buffer.setNumber(NumberFormat.UInt32BE, 12, getCurrentNumber())
  bluetooth.advertiseUidBuffer(buffer, POWER, CONNECTABLE)
})