fixed wall thermostat temp and setpoint

ivesdebruycker/node-red-contrib-maxcube#15

used info in https://github.com/Bouni/max-cube-protocol/blob/master/L-Message.md#actual-temperature-wallmountedthermostat to decode correctly the wall thermostat "Actual temperature" (temp) and "Temperature" (setpoint)

maxcube-commandparser.js

@@ -207,7 +207,7 @@ function decodeDevice (payload) {
   switch (payload[0]) {
     case 8: deviceType = EQ3MAX_DEV_TYPE_PUSH_BUTTON; break;
     case 11: deviceType = EQ3MAX_DEV_TYPE_THERMOSTAT; deviceStatus = decodeDeviceThermostat (payload); break;
-    case 12: deviceType = EQ3MAX_DEV_TYPE_WALLTHERMOSTAT; deviceStatus = decodeDeviceThermostat (payload); break;
+    case 12: deviceType = EQ3MAX_DEV_TYPE_WALLTHERMOSTAT; deviceStatus = decodeDeviceWallThermostat (payload); break;
     default: deviceType = EQ3MAX_DEV_TYPE_UNKNOWN; break;
   }
 
@@ -288,4 +288,44 @@ function decodeDeviceThermostat (payload) {
     return deviceStatus;
 }
 
-exports.parse = parse;
+function decodeDeviceWallThermostat (payload) {
+
+  //regular device parsing
+  var deviceStatus = decodeDeviceThermostat (payload);
+
+  //wall thermostat has different temp and setpoint parsing:
+  //https://github.com/Bouni/max-cube-protocol/blob/master/L-Message.md#actual-temperature-wallmountedthermostat
+
+  /*
+  Actual Temperature (WallMountedThermostat)
+
+  11      Actual Temperature  1           219
+  Room temperature measured by the wall mounted thermostat in °C * 10. For example 0xDB = 219 = 21.9°C The temperature is represented by 9 bits; the 9th bit is available as the top bit at offset 8
+
+  offset|      8    | ... |     12    |
+  hex   |     B2    |     |     24    |
+  binary| 1011 0010 | ... | 0010 0100 |
+          | || ||||         |||| ||||
+          | ++-++++--------------------- temperature (°C*2):            110010 = 25.0°C
+          |                 |||| ||||
+          +-----------------++++-++++--- actual temperature (°C*10): 100100100 = 29.2°C
+
+  */
+
+  //offset 8 binary to extract only needed bit
+  var off8Bin= (payload[8] >>> 0).toString(2);
+
+  //offset8 without top bit (it is used by actual temperature and will corrupt the setpoint value)
+  var setPoint = parseInt(((off8Bin + '').substring(1)).replace(/[^01]/gi, ''), 2);
+  //C/2
+  deviceStatus.setpoint = setPoint / 2;
+
+  //get the TopBit and zero fill right to use it as 9 bit of offset 12
+  var off8TopBit =  parseInt(off8Bin.substring(0,1)) << 8;
+  //Bitwise OR offset 8/offset 12 and finally C/10 to read the actual temperature
+  deviceStatus.temp = (parseInt(off8TopBit) | parseInt(payload[12])) / 10;
+
+  return deviceStatus;
+}
+
+exports.parse = parse;