Bangle.js2: Switched to proprietary heart rate algorithm (from our Open Source version). It just works better.

Author: gfwilliams

ChangeLog

@@ -14,6 +14,8 @@
             Puck.js: Ensure acc/gyro doesn't cause watch events to be added to the input queue (more efficient)
             Waveform: Fix waveform input/output when not done at system start - Since 2v13 start time was set in the past
             Fix ordering of Pin check in wrapper (so autocomplete and Pin prototype works)
+            Bangle.js2: Switched to 'hard' float abi from 'soft' (needed for proprietary hrm algorithm)
+            Bangle.js2: Switched to proprietary heart rate algorithm (from our Open Source version). It just works better. 
 
      2v17 : Bangle.js: When reading file info from a filename table, do it in blocks of 8 (20% faster file search)
             Bangle.js2: Increase flash buffer size from 16->32 bytes (5% performance increase)

boards/BANGLEJS2.py

@@ -68,8 +68,13 @@
      'WRAPPERSOURCES += libs/graphics/jswrap_font_12x20.c',
      'SOURCES += libs/misc/nmea.c',
      'SOURCES += libs/misc/stepcount.c',
-     'SOURCES += libs/misc/heartrate.c',
-     'SOURCES += libs/misc/hrm_vc31.c',
+     'SOURCES += libs/misc/hrm_vc31.c',     
+# Standard open-source heart rate algorithm:
+#    'SOURCES += libs/misc/heartrate.c',
+# Proprietary heart rate algorithm:
+     'FLOAT_ABI_HARD=1', # needed for VC31 binary algorithm
+     'SOURCES += libs/misc/heartrate_vc31_binary.c', 'DEFINES += -DHEARTRATE_VC31_BINARY=1', 'PRECOMPILED_OBJS += libs/misc/vc31_binary/algo.o libs/misc/vc31_binary/modle5_10.o libs/misc/vc31_binary/modle5_11.o libs/misc/vc31_binary/modle5_12.o libs/misc/vc31_binary/modle5_13.o libs/misc/vc31_binary/modle5_14.o libs/misc/vc31_binary/modle5_15.o libs/misc/vc31_binary/modle5_16.o libs/misc/vc31_binary/modle5_17.o libs/misc/vc31_binary/modle5_18.o libs/misc/vc31_binary/modle5_1.o libs/misc/vc31_binary/modle5_2.o libs/misc/vc31_binary/modle5_3.o libs/misc/vc31_binary/modle5_4.o libs/misc/vc31_binary/modle5_5.o libs/misc/vc31_binary/modle5_6.o libs/misc/vc31_binary/modle5_7.o libs/misc/vc31_binary/modle5_8.o libs/misc/vc31_binary/modle5_9.o',
+# ------------------------
      'SOURCES += libs/misc/unistroke.c',
      'WRAPPERSOURCES += libs/misc/jswrap_unistroke.c',
      'DEFINES += -DESPR_BANGLE_UNISTROKE=1',

libs/banglejs/jswrap_bangle.c

@@ -538,9 +538,6 @@ Can be used for housekeeping tasks that don't want to be run during the day.
 
 #define ACCEL_HISTORY_LEN 50 ///< Number of samples of accelerometer history
 
-typedef struct {
-  short x,y,z;
-} Vector3;
 
 // =========================================================================
 //                                            DEVICE SPECIFIC CONFIG
@@ -794,7 +791,7 @@ bool lcdFadeHandlerActive;
 // compass data
 Vector3 mag, magmin, magmax;
 #endif
-/// accelerometer data
+/// accelerometer data. 8192 = 1G
 Vector3 acc;
 /// squared accelerometer magnitude
 int accMagSquared;
@@ -1489,7 +1486,7 @@ void peripheralPollHandler() {
 
 #ifdef HEARTRATE
 static void hrmHandler(int ppgValue) {
-  if (hrm_new(ppgValue)) {
+  if (hrm_new(ppgValue, &acc)) {
     bangleTasks |= JSBT_HRM_DATA;
     // keep track of best HRM sample during this period
     if (hrmInfo.confidence >= healthCurrent.bpmConfidence) {
@@ -3910,13 +3907,13 @@ bool jswrap_banglejs_idle() {
 #ifdef HEARTRATE
     if (bangleTasks & JSBT_HRM_INSTANT_DATA) {
       JsVar *o = hrm_sensor_getJsVar();
-      if (o) {
+      if (o) {        
         jsvObjectSetChildAndUnLock(o,"raw",jsvNewFromInteger(hrmInfo.raw));
-        jsvObjectSetChildAndUnLock(o,"filt",jsvNewFromInteger(hrmInfo.filtered));
-        jsvObjectSetChildAndUnLock(o,"avg",jsvNewFromInteger(hrmInfo.avg));
-        jsvObjectSetChildAndUnLock(o,"isBeat",jsvNewFromBool(hrmInfo.isBeat));
         jsvObjectSetChildAndUnLock(o,"bpm",jsvNewFromFloat(hrmInfo.bpm10 / 10.0));
         jsvObjectSetChildAndUnLock(o,"confidence",jsvNewFromInteger(hrmInfo.confidence));
+        jsvObjectSetChildAndUnLock(o,"filt",jsvNewFromInteger(hrmInfo.filtered));
+        jsvObjectSetChildAndUnLock(o,"avg",jsvNewFromInteger(hrmInfo.avg));
+        hrm_get_hrm_raw_info(o);
         jsiQueueObjectCallbacks(bangle, JS_EVENT_PREFIX"HRM-raw", &o, 1);
         jsvUnLock(o);
       }
@@ -3926,16 +3923,7 @@ bool jswrap_banglejs_idle() {
       if (o) {
         jsvObjectSetChildAndUnLock(o,"bpm",jsvNewFromInteger(hrmInfo.bpm10 / 10.0));
         jsvObjectSetChildAndUnLock(o,"confidence",jsvNewFromInteger(hrmInfo.confidence));
-        JsVar *a = jsvNewEmptyArray();
-        if (a) {
-          int n = hrmInfo.timeIdx;
-          for (int i=0;i<HRM_HIST_LEN;i++) {
-            jsvArrayPushAndUnLock(a, jsvNewFromFloat(hrm_time_to_bpm10(hrmInfo.times[n]) / 10.0));
-            n++;
-            if (n==HRM_HIST_LEN) n=0;
-          }
-          jsvObjectSetChildAndUnLock(o,"history",a);
-        }
+        hrm_get_hrm_info(o);
         jsiQueueObjectCallbacks(bangle, JS_EVENT_PREFIX"HRM", &o, 1);
         jsvUnLock(o);
       }

libs/misc/heartrate.c

@@ -347,7 +347,7 @@ bool hrm_had_beat() {
 }
 
 /// Add new heart rate value
-bool hrm_new(int hrmValue) {
+bool hrm_new(int hrmValue, Vector3 *acc) {
   if (hrmValue<HRMVALUE_MIN) hrmValue=HRMVALUE_MIN;
   if (hrmValue>HRMVALUE_MAX) hrmValue=HRMVALUE_MAX;
   hrmInfo.raw = hrmValue;
@@ -379,3 +379,22 @@ bool hrm_new(int hrmValue) {
 
   return hadBeat;
 }
+
+// Append extra information to an existing HRM event object
+void hrm_get_hrm_info(JsVar *o) {
+  JsVar *a = jsvNewEmptyArray();
+  if (a) {
+    int n = hrmInfo.timeIdx;
+    for (int i=0;i<HRM_HIST_LEN;i++) {
+      jsvArrayPushAndUnLock(a, jsvNewFromFloat(hrm_time_to_bpm10(hrmInfo.times[n]) / 10.0));
+      n++;
+      if (n==HRM_HIST_LEN) n=0;
+    }
+    jsvObjectSetChildAndUnLock(o,"history",a);
+  }
+}
+
+// Append extra information to an existing HRM-raw event object
+void hrm_get_hrm_raw_info(JsVar *o) {
+  jsvObjectSetChildAndUnLock(o,"isBeat",jsvNewFromBool(hrmInfo.isBeat));
+}

libs/misc/heartrate.h

@@ -15,8 +15,10 @@
 
 #include "jsutils.h"
 
+#ifndef HEARTRATE_VC31_BINARY 
 #define HRM_HIST_LEN 16 // how many BPM values do we keep a history of
 #define HRM_MEDIAN_LEN 8 // how many BPM values do we average in our median filter to get a BPM reading
+#endif
 
 // Do we use 8 or 16 bits for data storage?
 #ifdef HEARTRATE_DEVICE_VC31
@@ -30,30 +32,42 @@
 #endif
 
 typedef struct {
+  uint16_t bpm10; // 10x BPM
+  uint8_t confidence; // 0..100%
+
   HrmValueType raw;
+  int16_t avg; // average signal value, moving average
   int16_t filtered;
+#ifndef HEARTRATE_VC31_BINARY  
   int16_t filtered1; // before filtered
   int16_t filtered2; // before filtered1
-  int16_t avg; // average signal value, moving average
-
   bool wasLow; // has the signal gone below the average? set =false when a beat detected
   bool isBeat; // was this sample classified as a detected beat?
   JsSysTime lastBeatTime; // timestamp of last heartbeat
   uint8_t times[HRM_HIST_LEN]; // times of previous beats, in 1/100th secs
   uint8_t timeIdx; // index in times
-  uint16_t bpm10; // 10x BPM
-  uint8_t confidence; // 0..100%
+#else // HEARTRATE_VC31_BINARY
+  bool isWorn; // is the bangle being worn? Used to re-init if we go from not worn to worn
+  JsSysTime lastPPGTime; // timestamp of last PPG sample
+  /* last values we got from the algo. It doesn't tell us when there's a new
+  value so we have to guess based on when it changes */
+  int lastHRM, lastConfidence; 
+  int msSinceLastHRM; // how long was it since the last HRM reading? 
+#endif
 } HrmInfo;
 
 extern HrmInfo hrmInfo;
 
-uint16_t hrm_time_to_bpm10(uint8_t time);
-
 /// Initialise heart rate monitoring
 void hrm_init();
 
 /// Add new heart rate value, return true if there was a heart beat
-bool hrm_new(int hrmValue);
+bool hrm_new(int hrmValue, Vector3 *acc);
 
 void hrm_sensor_on();
 void hrm_sensor_off();
+
+// Append extra information to an existing HRM event object
+void hrm_get_hrm_info(JsVar *var);
+// Append extra information to an existing HRM-raw event object
+void hrm_get_hrm_raw_info(JsVar *var);

libs/misc/heartrate_vc31_binary.c

@@ -0,0 +1,89 @@
+/*
+ * This file is part of Espruino, a JavaScript interpreter for Microcontrollers
+ *
+ * Copyright (C) 2021 Gordon Williams <gw@pur3.co.uk>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * ----------------------------------------------------------------------------
+ * heart rate monitoring using VC31 proprietary binary blob
+ * ----------------------------------------------------------------------------
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include "heartrate.h"
+#include "hrm_vc31.h"
+#include "hrm.h"
+#include "jshardware.h"
+#include "jsinteractive.h"
+#include "vc31_binary/algo.h"
+
+HrmInfo hrmInfo;
+
+/// Initialise heart rate monitoring
+void hrm_init() {
+  memset(&hrmInfo, 0, sizeof(hrmInfo));
+  hrmInfo.isWorn = false;
+  hrmInfo.lastPPGTime = jshGetSystemTime();  
+}
+
+/// Add new heart rate value
+bool hrm_new(int ppgValue, Vector3 *acc) {
+  // work out time passed since last sample (it might not be exactly hrmUpdateInterval)
+  JsSysTime time = jshGetSystemTime();
+  int timeDiff = (int)(jshGetMillisecondsFromTime(time-hrmInfo.lastPPGTime)+0.5);
+  hrmInfo.lastPPGTime = time;
+  // if we've just started wearing again, reset the algorith
+  if (vcInfo.isWearing && !hrmInfo.isWorn) {
+    hrmInfo.isWorn = true;
+    // initialise VC31 algorithm (should do when going from wearing to not wearing)
+    Algo_Init();
+    hrmInfo.lastHRM = 0;
+    hrmInfo.lastConfidence = 0; 
+    hrmInfo.msSinceLastHRM = 0;
+    hrmInfo.avg = ppgValue;
+  } else {
+    hrmInfo.isWorn = vcInfo.isWearing;
+    if (!hrmInfo.isWorn) return false;
+  }
+  hrmInfo.filtered = ppgValue-hrmInfo.avg;
+  hrmInfo.avg = (hrmInfo.avg*15 + ppgValue) >> 4;  
+  // Feed data into algorithm
+  AlgoInputData_t inputData;
+  inputData.axes.x = acc->y >> 5;  // perpendicular to the direction of the arm
+  inputData.axes.y = acc->x >> 5;  // along the direction of the arm
+  inputData.axes.z = acc->z >> 5;
+  inputData.ppgSample = vcInfo.ppgValue | (vcInfo.wasAdjusted ? 0x1000 : 0);
+  inputData.envSample = vcInfo.envValue;
+  hrmInfo.msSinceLastHRM += timeDiff;
+  Algo_Input(&inputData, timeDiff, SPORT_TYPE_NORMAL,0/*surfaceRecogMode*/,0/*opticalAidMode*/);
+  AlgoOutputData_t outputData;
+  Algo_Output(&outputData);
+  jsiConsolePrintf("HRM %d %d %d\n", outputData.hrData, outputData.reliability, hrmInfo.msSinceLastHRM);
+  if (outputData.hrData!=hrmInfo.lastHRM ||
+      outputData.reliability!=hrmInfo.lastConfidence ||
+      ((hrmInfo.msSinceLastHRM > 2000) && outputData.hrData && outputData.reliability)) {
+    // update when figures change OR when 2 secs have passed (readings are usually every 1 sec)
+    hrmInfo.lastConfidence = outputData.reliability;
+    hrmInfo.lastHRM = outputData.hrData;
+    hrmInfo.bpm10 = 10 * outputData.hrData;
+    hrmInfo.confidence = outputData.reliability;
+    hrmInfo.msSinceLastHRM = 0;
+    return true;
+  }
+  return false;
+}
+
+// Append extra information to an existing HRM event object
+void hrm_get_hrm_info(JsVar *o) {
+  NOT_USED(o);
+}
+
+// Append extra information to an existing HRM-raw event object
+void hrm_get_hrm_raw_info(JsVar *o) {
+}

libs/misc/hrm_vc31.c

@@ -13,6 +13,7 @@
  */
 
 #include "hrm.h"
+#include "hrm_vc31.h"
 #include "jsutils.h"
 #include "platform_config.h"
 #include "jshardware.h"
@@ -164,25 +165,6 @@ typedef enum {
   VC31B_DEVICE
 } VC31Type;
 
-// Hack to fix Eclipse syntax lint
-#ifndef PACKED_FLAGS
-#define PACKED_FLAGS
-#endif
-// ---
-
-// VC31 info shared between VC31A/B
-typedef struct {
-  bool isWearing;
-  int8_t isWearCnt, unWearCnt; // counters for switching worn/unworn state
-  uint16_t ppgValue; // current PPG value
-  uint16_t ppgLastValue; // last PPG value
-  int16_t ppgOffset; // PPG 'offset' value. When PPG adjusts we change the offset so it matches the last value, then slowly adjust 'ppgOffset' back down to 0
-  uint8_t wasAdjusted; // true if LED/etc adjusted since the last reading
-  // the meaning of these is device-dependent but it's nice to have them in one place
-  uint8_t irqStatus;
-  uint8_t raw[12];
-} PACKED_FLAGS VC31Info;
-
 // VC31A-specific info
 typedef struct {
   uint8_t ctrl; // current VC31A_CTRL reg value
@@ -191,7 +173,6 @@ typedef struct {
   uint16_t envValue;
   uint16_t psValue;
   VC31AdjustInfo_t adjustInfo;
-
 } PACKED_FLAGS VC31AInfo;
 // VC31B-specific info
 typedef struct {
@@ -591,6 +572,7 @@ void vc31_irqhandler(bool state, IOEventFlags flags) {
     vcaInfo.preValue = (buf[6] << 8) | buf[5];
     vcaInfo.psValue = (buf[8] << 8) | buf[7];
     vcaInfo.envValue = (buf[10] << 8) | buf[9];
+    vcInfo.envValue = vcaInfo.envValue;
 
     if (vcInfo.irqStatus & VC31A_STATUS_D_PPG_OK) {
       vc31_new_ppg(ppgValue); // send PPG value
@@ -614,7 +596,7 @@ void vc31_irqhandler(bool state, IOEventFlags flags) {
     vcbInfo.sampleData.envValue[1] = buf[4] >> 4;
     vcbInfo.sampleData.preValue[1] = buf[4] & 0x0F;
     vcbInfo.sampleData.envValue[2] = buf[5] >> 4;
-    vcbInfo.sampleData.psValue = buf[5] & 0x0F;
+    vcbInfo.sampleData.psValue = buf[5] & 0x0F;    
     buf = &vcInfo.raw[6];
     vc31_rx(VC31B_REG17, buf, 6);
     vcbInfo.sampleData.pdResValue[0] = (buf[3] >> 4) & 0x07;
@@ -626,6 +608,7 @@ void vc31_irqhandler(bool state, IOEventFlags flags) {
 
     // if we had environment sensing, check for wear status and update LEDs accordingly
     if (vcInfo.irqStatus & VC31B_INT_PS) {
+      vcInfo.envValue = vcbInfo.sampleData.envValue[2];
       //jsiConsolePrintf("e %d %d\n", vcbInfo.sampleData.psValue, vcbInfo.sampleData.envValue[2] );
       vc31b_wearstatus();
     }

libs/misc/hrm_vc31.h

@@ -0,0 +1,39 @@
+/*
+ * This file is part of Espruino, a JavaScript interpreter for Microcontrollers
+ *
+ * Copyright (C) 2019 Gordon Williams <gw@pur3.co.uk>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * ----------------------------------------------------------------------------
+ * VC31 heart rate sensor - additional info
+ * ----------------------------------------------------------------------------
+ */
+
+#ifndef EMULATED
+
+// Hack to fix Eclipse syntax lint
+#ifndef PACKED_FLAGS
+#define PACKED_FLAGS
+#endif
+// ---
+
+// VC31 info shared between VC31A/B
+typedef struct {
+  bool isWearing;
+  int8_t isWearCnt, unWearCnt; // counters for switching worn/unworn state
+  uint16_t ppgValue; // current PPG value
+  uint16_t ppgLastValue; // last PPG value
+  int16_t ppgOffset; // PPG 'offset' value. When PPG adjusts we change the offset so it matches the last value, then slowly adjust 'ppgOffset' back down to 0
+  uint8_t wasAdjusted; // true if LED/etc adjusted since the last reading
+  uint16_t envValue; // env value (but VC31B has 3 value slots so we just use the one we know is ok here)
+  // the meaning of these is device-dependent but it's nice to have them in one place
+  uint8_t irqStatus;
+  uint8_t raw[12];
+} PACKED_FLAGS VC31Info;
+
+extern VC31Info vcInfo;
+
+#endif