Added defensive programming

app/peripherals/ble/ftms/RowerDataCharacteristic.js

@@ -1,6 +1,6 @@
 'use strict'
 /*
-  Open Rowing Monitor, https://github.com/laberning/openrowingmonitor
+  Open Rowing Monitor, https://github.com/JaapvanEkris/openrowingmonitor
 
   This implements the Rower Data Characteristic as defined by the Bluetooth SIG
   Currently not many applications exist that support thes FTMS Characteristic for Rowing so its hard
@@ -61,32 +61,32 @@ export default class RowerDataCharacteristic extends bleno.Characteristic {
       // see https://www.bluetooth.com/specifications/specs/gatt-specification-supplement-3/
       // for some of the data types
       // Stroke Rate in stroke/minute, value is multiplied by 2 to have a .5 precision
-      bufferBuilder.writeUInt8(Math.round(data.cycleStrokeRate * 2))
+      bufferBuilder.writeUInt8(data.cycleStrokeRate > 0 ? Math.round(data.cycleStrokeRate * 2) : 0)
       // Stroke Count
-      bufferBuilder.writeUInt16LE(Math.round(data.totalNumberOfStrokes))
+      bufferBuilder.writeUInt16LE(data.totalNumberOfStrokes > 0 ? Math.round(data.totalNumberOfStrokes) : 0)
       // Total Distance in meters
-      bufferBuilder.writeUInt24LE(Math.round(data.totalLinearDistance))
+      bufferBuilder.writeUInt24LE(data.totalLinearDistance > 0 ? Math.round(data.totalLinearDistance) : 0)
       // Instantaneous Pace in seconds/500m
       // if split is infinite (i.e. while pausing), should use the highest possible number (0xFFFF)
       // todo: eventhough mathematically correct, setting 0xFFFF (65535s) causes some ugly spikes
       // in some applications which could shift the axis (i.e. workout diagrams in MyHomeFit)
       // so instead for now we use 0 here
       bufferBuilder.writeUInt16LE(data.cyclePace !== Infinity && data.cyclePace < 65535 ? Math.round(data.cyclePace) : 0xFFFF)
       // Instantaneous Power in watts
-      bufferBuilder.writeUInt16LE(Math.round(data.cyclePower))
+      bufferBuilder.writeUInt16LE(data.cyclePower > 0 ? Math.round(data.cyclePower) : 0)
       // Energy in kcal
       // Total energy in kcal
-      bufferBuilder.writeUInt16LE(Math.round(data.totalCalories))
+      bufferBuilder.writeUInt16LE(data.totalCalories > 0 ? Math.round(data.totalCalories) : 0)
       // Energy per hour
       // The Energy per Hour field represents the average expended energy of a user during a
       // period of one hour.
-      bufferBuilder.writeUInt16LE(Math.round(data.totalCaloriesPerHour))
+      bufferBuilder.writeUInt16LE(data.totalCaloriesPerHour > 0 ? Math.round(data.totalCaloriesPerHour) : 0)
       // Energy per minute
-      bufferBuilder.writeUInt8(Math.round(data.totalCaloriesPerMinute))
+      bufferBuilder.writeUInt8(data.totalCaloriesPerMinute > 0 ? Math.round(data.totalCaloriesPerMinute) : 0)
       // Heart Rate: Beats per minute with a resolution of 1
-      bufferBuilder.writeUInt8(Math.round(data.heartrate))
+      bufferBuilder.writeUInt8(data.heartrate > 0 ? Math.round(data.heartrate) : 0)
       // Elapsed Time: Seconds with a resolution of 1
-      bufferBuilder.writeUInt16LE(Math.round(data.totalMovingTime))
+      bufferBuilder.writeUInt16LE(data.totalMovingTime > 0 ? Math.round(data.totalMovingTime) : 0)
 
       const buffer = bufferBuilder.getBuffer()
       if (buffer.length > this._subscriberMaxValueSize) {