Bangle.js2: Add Bangle.setOptions({hrmStaticSampleTime})

Author: gfwilliams

ChangeLog

@@ -5,6 +5,7 @@
             MDBT42Q: Remove SHA512 from the build (needs 2.5k flash, rarely used)
             Bangle.js2: Adjust accelerometer axes for HRM algorithm to more closely match the datasheet
             nRF52: Add NRF/BluetoothRemoteGATTServer.updateConnection for setting the phy
+            Bangle.js2: Add Bangle.setOptions({hrmStaticSampleTime})
 
      2v27 : nRF5x: Ensure Bluetooth notifications work correctly when two separate connections use the same handle for their characteristics
             nRF5x: Remove handlers from our handlers array when a device is disconnected

libs/banglejs/jswrap_bangle.c

@@ -2721,6 +2721,7 @@ call `E.kickWatchdog()` from your code or the watch will reset after ~5 seconds.
 * `hrmGreenAdjust` - (Bangle.js 2, 2v19+) if false (default is true) the green LED intensity won't be adjusted to get the HRM sensor 'exposure' correct. This is reset when the HRM is initialised with `Bangle.setHRMPower`.
 * `hrmWearDetect` - (Bangle.js 2, 2v19+) if false (default is true) HRM readings won't be turned off if the watch isn't on your arm (based on HRM proximity sensor). This is reset when the HRM is initialised with `Bangle.setHRMPower`.
 * `hrmPushEnv` - (Bangle.js 2, 2v19+) if true (default is false) HRM environment readings will be produced as `Bangle.on(`HRM-env`, ...)` events. This is reset when the HRM is initialised with `Bangle.setHRMPower`.
+* `hrmStaticSampleTime` - (Bangle.js 2, 2v28+) if true (default is false) force the HRM to use hrmPollInterval as the sample time rather than the real poll interval
 * `seaLevelPressure` (Bangle.js 2) Default 1013.25 millibars - this is used when calculating altitude from pressure sensor values from `Bangle.getPressure`/`pressure` events.
 * `lcdBufferPtr` (Bangle.js 2 2v21+) Return a pointer to the first pixel of the 3 bit graphics buffer used by Bangle.js for the screen (stride = 178 bytes)
 * `lcdDoubleRefresh` (Bangle.js 2 2v22+) If enabled, pulses EXTCOMIN twice per poll interval (avoids off-axis flicker)
@@ -2771,6 +2772,7 @@ JsVar * _jswrap_banglejs_setOptions(JsVar *options, bool createObject) {
       {"hrmGreenAdjust", JSV_BOOLEAN, &vcInfo.allowGreenAdjust},
       {"hrmWearDetect", JSV_BOOLEAN, &vcInfo.allowWearDetect},
       {"hrmPushEnv", JSV_BOOLEAN, &vcInfo.pushEnvData},
+      {"hrmStaticSampleTime", JSV_BOOLEAN, &vcInfo.useStaticSampleTime},
 #endif
 #ifdef PRESSURE_DEVICE
       {"seaLevelPressure", JSV_FLOAT, &barometerSeaLevelPressure},

libs/misc/heartrate_vc31_binary.c

@@ -70,7 +70,7 @@ bool hrm_new(int ppgValue, Vector3 *acc) {
   inputData.envSample = vcInfo.envValue;
   hrmInfo.msSinceLastHRM += timeDiff;
   // TODO: The VC31 example code uses a static value here (eg hrmPollInterval) - maybe we should do this
-  Algo_Input(&inputData, timeDiff, hrmInfo.sportMode, 0/*surfaceRecogMode*/,0/*opticalAidMode*/);
+  Algo_Input(&inputData, vcInfo.useStaticSampleTime ?  hrmPollInterval : timeDiff, hrmInfo.sportMode, 0/*surfaceRecogMode*/,0/*opticalAidMode*/);
   AlgoOutputData_t outputData;
   Algo_Output(&outputData);
   //jsiConsolePrintf("HRM %d %d %d\n", outputData.hrData, outputData.reliability, hrmInfo.msSinceLastHRM);

libs/misc/hrm_vc31.h

@@ -36,6 +36,7 @@ typedef struct {
   bool allowGreenAdjust; // allow automatic adjustment of LED power
   bool allowWearDetect; // allow automatic check for whether HRM is worn
   bool pushEnvData; // call jsbangle_push_event to push data for every received ENV sample
+  bool useStaticSampleTime; // use a static time period for samples, rather than the time between them
 } PACKED_FLAGS VC31Info;
 
 extern VC31Info vcInfo;