itsmepetrov · July 27, 2018 17:52 · Jul 27, 2018
diff --git a/xiaomi.js b/xiaomi.js
@@ -0,0 +1,36 @@
+const XIAOMI_STRUCT_ATTR = { id: 65281, type: 'charStr' }
+const XIAOMI_STRUCT_OLD_ATTR = { id: 65282, type: 'charStr' }
+const XIAOMI_MULTICLICK_ATTR = { id: 32768, type: 'boolean' }
+const XIAOMI_PRESSURE_ATTR = { id: 16, type: 'int16' }
+
+function parseXiaomiStruct(rawData) {
+  const buffer = new Buffer(rawData, 'ascii')
+  const data = {}
+  let index = 0
+  while (index < buffer.length) {
+    const type = buffer.readUInt8(index + 1)
+    const byteLength = (type & 0x7) + 1
+    const isSigned = Boolean((type >> 3) & 1)
+    data[buffer.readUInt8(index)] = buffer[isSigned ? 'readIntLE' : 'readUIntLE'](index + 2, byteLength)
+    index += byteLength + 2
+  }
+  return data
+}
+
+function parseXiaomiBatteryInfo(rawData) {
+  const data = parseXiaomiStruct(rawData)
+  const batteryData = data[1]
+  return {
+    voltage: batteryData / 1000, // voltage (v)
+    battery: (batteryData - 2700) / 5 // percent (%)
+  }
+}
+
+module.exports = {
+  XIAOMI_STRUCT_ATTR,
+  XIAOMI_STRUCT_OLD_ATTR,
+  XIAOMI_MULTICLICK_ATTR,
+  XIAOMI_PRESSURE_ATTR,
+  parseXiaomiStruct,
+  parseXiaomiBatteryInfo,
+}