From 979f0f97b961cb718655754ab8cd80b90f6115d2 Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Tue, 5 Apr 2022 22:22:30 +0000
Subject: [PATCH 1/7] replace magic number 200 with const DATA_SIZE we can
 replace dataIndex in ProcessHeartRate, because it was only being called if
 dataIndex is 200 anyway (see line 61-67) and the Trough function expects its
 second argument to be the size and not an index.

---
 src/components/heartrate/Ppg.cpp | 12 ++++++------
 src/components/heartrate/Ppg.h   |  3 ++-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index a5d836966a..0c36eb3c68 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -52,13 +52,13 @@ int8_t Ppg::Preprocess(float spl) {
 
   auto spl_int = static_cast<int8_t>(spl);
 
-  if (dataIndex < 200)
+  if (dataIndex < DATA_SIZE)
     data[dataIndex++] = spl_int;
   return spl_int;
 }
 
 float Ppg::HeartRate() {
-  if (dataIndex < 200)
+  if (dataIndex < DATA_SIZE)
     return 0;
 
   NRF_LOG_INFO("PREPROCESS, offset = %d", offset);
@@ -67,22 +67,22 @@ float Ppg::HeartRate() {
   return hr;
 }
 float Ppg::ProcessHeartRate() {
-  auto t0 = Trough(data.data(), dataIndex, 7, 48);
+  auto t0 = Trough(data.data(), DATA_SIZE, 7, 48);
   if (t0 < 0)
     return 0;
 
   float t1 = t0 * 2;
-  t1 = Trough(data.data(), dataIndex, t1 - 5, t1 + 5);
+  t1 = Trough(data.data(), DATA_SIZE, t1 - 5, t1 + 5);
   if (t1 < 0)
     return 0;
 
   float t2 = static_cast<int>(t1 * 3) / 2;
-  t2 = Trough(data.data(), dataIndex, t2 - 5, t2 + 5);
+  t2 = Trough(data.data(), DATA_SIZE, t2 - 5, t2 + 5);
   if (t2 < 0)
     return 0;
 
   float t3 = static_cast<int>(t2 * 4) / 3;
-  t3 = Trough(data.data(), dataIndex, t3 - 4, t3 + 4);
+  t3 = Trough(data.data(), DATA_SIZE, t3 - 4, t3 + 4);
   if (t3 < 0)
     return static_cast<int>(60 * 24 * 3) / static_cast<int>(t2);
 
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index 7000c8710b..9095c75a43 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -18,7 +18,8 @@ namespace Pinetime {
       void Reset();
 
     private:
-      std::array<int8_t, 200> data;
+      static const uint8_t DATA_SIZE = 200;
+      std::array<int8_t, DATA_SIZE> data;
       size_t dataIndex = 0;
       float offset;
       Biquad hpf;

From 254fb846ce1bf577fda40c0d13697d9f7c0de9ce Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Thu, 14 Apr 2022 23:04:45 +0000
Subject: [PATCH 2/7] ring buffer impl for processing of hr sensor data

---
 src/components/heartrate/Ppg.cpp | 57 +++++++++++++++++---------------
 src/components/heartrate/Ppg.h   |  6 +++-
 2 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index 0c36eb3c68..47c0d38fc9 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -10,21 +10,25 @@
 using namespace Pinetime::Controllers;
 
 /** Original implementation from wasp-os : https://github.com/daniel-thompson/wasp-os/blob/master/wasp/ppg.py */
-namespace {
-  int Compare(int8_t* d1, int8_t* d2, size_t count) {
+Ppg::Ppg()
+  : hpf {0.87033078, -1.74066156, 0.87033078, -1.72377617, 0.75754694},
+    agc {20, 0.971, 2},
+    lpf {0.11595249, 0.23190498, 0.11595249, -0.72168143, 0.18549138} {
+}
+
+  int Ppg::Compare(int8_t* d1,int shift, size_t count) {
     int e = 0;
     for (size_t i = 0; i < count; i++) {
-      auto d = d1[i] - d2[i];
+      auto d = d1[getRingIndex(i+shift)] - d1[getRingIndex(i)];
       e += d * d;
     }
     return e;
   }
 
-  int CompareShift(int8_t* d, int shift, size_t count) {
-    return Compare(d + shift, d, count - shift);
+  int Ppg::CompareShift(int8_t* d, int shift, size_t count) {
+    return Compare(d ,shift, count - shift);
   }
-
-  int Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx) {
+  int Ppg::Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx) {
     auto z2 = CompareShift(d, mn - 2, size);
     auto z1 = CompareShift(d, mn - 1, size);
     for (int i = mn; i < mx + 1; i++) {
@@ -36,13 +40,6 @@ namespace {
     }
     return -1;
   }
-}
-
-Ppg::Ppg()
-  : hpf {0.87033078, -1.74066156, 0.87033078, -1.72377617, 0.75754694},
-    agc {20, 0.971, 2},
-    lpf {0.11595249, 0.23190498, 0.11595249, -0.72168143, 0.18549138} {
-}
 
 int8_t Ppg::Preprocess(float spl) {
   spl -= offset;
@@ -52,43 +49,49 @@ int8_t Ppg::Preprocess(float spl) {
 
   auto spl_int = static_cast<int8_t>(spl);
 
-  if (dataIndex < DATA_SIZE)
-    data[dataIndex++] = spl_int;
+  data[dataIndex] = spl_int;
+  dataIndex = (dataIndex+1)%Ppg::DATA_SIZE;
   return spl_int;
 }
 
 float Ppg::HeartRate() {
-  if (dataIndex < DATA_SIZE)
+  if(data[DATA_SIZE-1] == 0){
     return 0;
+  }
 
   NRF_LOG_INFO("PREPROCESS, offset = %d", offset);
   auto hr = ProcessHeartRate();
-  dataIndex = 0;
   return hr;
 }
 float Ppg::ProcessHeartRate() {
-  auto t0 = Trough(data.data(), DATA_SIZE, 7, 48);
+  int t0 = Trough(data.data(), DATA_SIZE, 7, 48);
   if (t0 < 0)
     return 0;
 
-  float t1 = t0 * 2;
-  t1 = Trough(data.data(), DATA_SIZE, t1 - 5, t1 + 5);
+  int t1 = t0 * 2;
+  t1 = Trough(data.data(), DATA_SIZE, (t1 - 5), (t1 + 5));
   if (t1 < 0)
     return 0;
 
-  float t2 = static_cast<int>(t1 * 3) / 2;
-  t2 = Trough(data.data(), DATA_SIZE, t2 - 5, t2 + 5);
+  int t2 = (t1 * 3) / 2;
+  t2 = Trough(data.data(), DATA_SIZE,(t2 - 5),(t2 + 5));
   if (t2 < 0)
     return 0;
 
-  float t3 = static_cast<int>(t2 * 4) / 3;
-  t3 = Trough(data.data(), DATA_SIZE, t3 - 4, t3 + 4);
+  int t3 = (t2 * 4) / 3;
+  t3 = Trough(data.data(), DATA_SIZE,(t3 - 4), (t3 + 4));
   if (t3 < 0)
-    return static_cast<int>(60 * 24 * 3) / static_cast<int>(t2);
+    return (60 * 24 * 3) / (t2);
 
-  return static_cast<int>(60 * 24 * 4) / static_cast<int>(t3);
+  return (60 * 24 * 4) / (t3);
 }
 
+//Gets the Index in the Ring Buffer which corresponds to the index, if it was a 0-based Array
+//DataIndex is where there was last data written to, so if the arrray was full once, it marks the end of the array
+//The next Index is the start then.
+int Ppg::getRingIndex(int8_t index){
+  return (index+dataIndex)%Ppg::DATA_SIZE;
+}
 void Ppg::SetOffset(uint16_t offset) {
   this->offset = offset;
   dataIndex = 0;
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index 9095c75a43..bf4249c288 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -10,15 +10,19 @@ namespace Pinetime {
   namespace Controllers {
     class Ppg {
     public:
+      static const uint8_t DATA_SIZE = 200;
       Ppg();
       int8_t Preprocess(float spl);
       float HeartRate();
 
       void SetOffset(uint16_t i);
       void Reset();
+      int Compare(int8_t* d1, int shift, size_t count);
+      int CompareShift(int8_t* d, int shift, size_t count);
+      int Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx);
+      int getRingIndex(int8_t index);
 
     private:
-      static const uint8_t DATA_SIZE = 200;
       std::array<int8_t, DATA_SIZE> data;
       size_t dataIndex = 0;
       float offset;

From c59f9b560834575dfde3fe4222b3f33b77d3e85b Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Fri, 15 Apr 2022 13:00:28 +0000
Subject: [PATCH 3/7] variable to change the freq of heart rate update

---
 src/components/heartrate/Ppg.cpp | 6 ++++--
 src/components/heartrate/Ppg.h   | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index 47c0d38fc9..a6a8938293 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -55,7 +55,7 @@ int8_t Ppg::Preprocess(float spl) {
 }
 
 float Ppg::HeartRate() {
-  if(data[DATA_SIZE-1] == 0){
+  if(data[DATA_SIZE-1] == 0 || dataIndex% Ppg::UPDATE_HEARTRATE_AFTER != 0){
     return 0;
   }
 
@@ -94,9 +94,11 @@ int Ppg::getRingIndex(int8_t index){
 }
 void Ppg::SetOffset(uint16_t offset) {
   this->offset = offset;
-  dataIndex = 0;
+  this->Reset();
 }
 
 void Ppg::Reset() {
   dataIndex = 0;
+  //invalidates the current array
+  data[DATA_SIZE-1] = 0;
 }
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index bf4249c288..4e0da19110 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -23,6 +23,7 @@ namespace Pinetime {
       int getRingIndex(int8_t index);
 
     private:
+    static const uint8_t UPDATE_HEARTRATE_AFTER = 200;
       std::array<int8_t, DATA_SIZE> data;
       size_t dataIndex = 0;
       float offset;

From ef84a228f4be4405d5a47c39eae7a8c947783f92 Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Fri, 15 Apr 2022 15:45:30 +0000
Subject: [PATCH 4/7] some clang-tidy cleanups/autoformat changed data Type of
 heartrate to int, it is only used as an int anyway

---
 src/components/heartrate/Ppg.cpp | 83 +++++++++++++++++---------------
 src/components/heartrate/Ppg.h   | 14 +++---
 2 files changed, 50 insertions(+), 47 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index a6a8938293..8bc3ab9fd8 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -5,8 +5,8 @@
 */
 
 #include "components/heartrate/Ppg.h"
-#include <vector>
 #include <nrf_log.h>
+#include <vector>
 using namespace Pinetime::Controllers;
 
 /** Original implementation from wasp-os : https://github.com/daniel-thompson/wasp-os/blob/master/wasp/ppg.py */
@@ -16,30 +16,30 @@ Ppg::Ppg()
     lpf {0.11595249, 0.23190498, 0.11595249, -0.72168143, 0.18549138} {
 }
 
-  int Ppg::Compare(int8_t* d1,int shift, size_t count) {
-    int e = 0;
-    for (size_t i = 0; i < count; i++) {
-      auto d = d1[getRingIndex(i+shift)] - d1[getRingIndex(i)];
-      e += d * d;
-    }
-    return e;
+int Ppg::Compare(int8_t* d1, int shift, size_t count) {
+  int e = 0;
+  for (size_t i = 0; i < count; i++) {
+    auto d = d1[getRingIndex(i + shift)] - d1[getRingIndex(i)];
+    e += d * d;
   }
+  return e;
+}
 
-  int Ppg::CompareShift(int8_t* d, int shift, size_t count) {
-    return Compare(d ,shift, count - shift);
-  }
-  int Ppg::Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx) {
-    auto z2 = CompareShift(d, mn - 2, size);
-    auto z1 = CompareShift(d, mn - 1, size);
-    for (int i = mn; i < mx + 1; i++) {
-      auto z = CompareShift(d, i, size);
-      if (z2 > z1 && z1 < z)
-        return i;
-      z2 = z1;
-      z1 = z;
-    }
-    return -1;
+int Ppg::CompareShift(int8_t* d, int shift, size_t count) {
+  return Compare(d, shift, count - shift);
+}
+int Ppg::Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx) {
+  auto z2 = CompareShift(d, mn - 2, size);
+  auto z1 = CompareShift(d, mn - 1, size);
+  for (int i = mn; i < mx + 1; i++) {
+    auto z = CompareShift(d, i, size);
+    if (z2 > z1 && z1 < z)
+      return i;
+    z2 = z1;
+    z1 = z;
   }
+  return -1;
+}
 
 int8_t Ppg::Preprocess(float spl) {
   spl -= offset;
@@ -50,47 +50,50 @@ int8_t Ppg::Preprocess(float spl) {
   auto spl_int = static_cast<int8_t>(spl);
 
   data[dataIndex] = spl_int;
-  dataIndex = (dataIndex+1)%Ppg::DATA_SIZE;
+  dataIndex = (dataIndex + 1) % Ppg::DATA_SIZE;
   return spl_int;
 }
 
-float Ppg::HeartRate() {
-  if(data[DATA_SIZE-1] == 0 || dataIndex% Ppg::UPDATE_HEARTRATE_AFTER != 0){
+int Ppg::HeartRate() {
+  if (data[DATA_SIZE - 1] == 0 || dataIndex % Ppg::UPDATE_HEARTRATE_AFTER != 0) {
     return 0;
   }
 
   NRF_LOG_INFO("PREPROCESS, offset = %d", offset);
-  auto hr = ProcessHeartRate();
+  int hr = ProcessHeartRate();
   return hr;
 }
-float Ppg::ProcessHeartRate() {
+int Ppg::ProcessHeartRate() {
   int t0 = Trough(data.data(), DATA_SIZE, 7, 48);
-  if (t0 < 0)
+  if (t0 < 0) {
     return 0;
+  }
 
   int t1 = t0 * 2;
   t1 = Trough(data.data(), DATA_SIZE, (t1 - 5), (t1 + 5));
-  if (t1 < 0)
+  if (t1 < 0) {
     return 0;
+  }
 
   int t2 = (t1 * 3) / 2;
-  t2 = Trough(data.data(), DATA_SIZE,(t2 - 5),(t2 + 5));
-  if (t2 < 0)
+  t2 = Trough(data.data(), DATA_SIZE, (t2 - 5), (t2 + 5));
+  if (t2 < 0) {
     return 0;
+  }
 
   int t3 = (t2 * 4) / 3;
-  t3 = Trough(data.data(), DATA_SIZE,(t3 - 4), (t3 + 4));
-  if (t3 < 0)
+  t3 = Trough(data.data(), DATA_SIZE, (t3 - 4), (t3 + 4));
+  if (t3 < 0) {
     return (60 * 24 * 3) / (t2);
+  }
 
   return (60 * 24 * 4) / (t3);
 }
 
-//Gets the Index in the Ring Buffer which corresponds to the index, if it was a 0-based Array
-//DataIndex is where there was last data written to, so if the arrray was full once, it marks the end of the array
-//The next Index is the start then.
-int Ppg::getRingIndex(int8_t index){
-  return (index+dataIndex)%Ppg::DATA_SIZE;
+// Gets the Index in the Ring Buffer which corresponds to the index, if it was a 0-based Array
+// dataIndex points to the next index to write to, so it is the start of the buffer and the last element is at dataIndex-1
+int Ppg::getRingIndex(int8_t index) {
+  return (index + dataIndex) % Ppg::DATA_SIZE;
 }
 void Ppg::SetOffset(uint16_t offset) {
   this->offset = offset;
@@ -99,6 +102,6 @@ void Ppg::SetOffset(uint16_t offset) {
 
 void Ppg::Reset() {
   dataIndex = 0;
-  //invalidates the current array
-  data[DATA_SIZE-1] = 0;
+  // invalidates the current array
+  data[DATA_SIZE - 1] = 0;
 }
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index 4e0da19110..d0e6e13483 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -13,17 +13,13 @@ namespace Pinetime {
       static const uint8_t DATA_SIZE = 200;
       Ppg();
       int8_t Preprocess(float spl);
-      float HeartRate();
+      int HeartRate();
 
       void SetOffset(uint16_t i);
       void Reset();
-      int Compare(int8_t* d1, int shift, size_t count);
-      int CompareShift(int8_t* d, int shift, size_t count);
-      int Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx);
-      int getRingIndex(int8_t index);
 
     private:
-    static const uint8_t UPDATE_HEARTRATE_AFTER = 200;
+      static const uint8_t UPDATE_HEARTRATE_AFTER = 200;
       std::array<int8_t, DATA_SIZE> data;
       size_t dataIndex = 0;
       float offset;
@@ -31,7 +27,11 @@ namespace Pinetime {
       Ptagc agc;
       Biquad lpf;
 
-      float ProcessHeartRate();
+      int getRingIndex(int8_t index);
+      int Compare(int8_t* d1, int shift, size_t count);
+      int CompareShift(int8_t* d, int shift, size_t count);
+      int Trough(int8_t* d, size_t size, uint8_t mn, uint8_t mx);
+      int ProcessHeartRate();
     };
   }
 }

From c6d76739ff18585eac6d41720b82ea4d24bf5b27 Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Mon, 25 Apr 2022 17:14:28 +0000
Subject: [PATCH 5/7] replaced DATA_SIZE variable with data.size()

---
 src/components/heartrate/Ppg.cpp | 16 ++++++++--------
 src/components/heartrate/Ppg.h   |  3 +--
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index 8bc3ab9fd8..fa1a52f7c3 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -50,12 +50,12 @@ int8_t Ppg::Preprocess(float spl) {
   auto spl_int = static_cast<int8_t>(spl);
 
   data[dataIndex] = spl_int;
-  dataIndex = (dataIndex + 1) % Ppg::DATA_SIZE;
+  dataIndex = (dataIndex + 1) % Ppg::data.size();
   return spl_int;
 }
 
 int Ppg::HeartRate() {
-  if (data[DATA_SIZE - 1] == 0 || dataIndex % Ppg::UPDATE_HEARTRATE_AFTER != 0) {
+  if (data[data.size() - 1] == 0 || dataIndex % Ppg::UPDATE_HEARTRATE_AFTER != 0) {
     return 0;
   }
 
@@ -64,25 +64,25 @@ int Ppg::HeartRate() {
   return hr;
 }
 int Ppg::ProcessHeartRate() {
-  int t0 = Trough(data.data(), DATA_SIZE, 7, 48);
+  int t0 = Trough(data.data(), data.size(), 7, 48);
   if (t0 < 0) {
     return 0;
   }
 
   int t1 = t0 * 2;
-  t1 = Trough(data.data(), DATA_SIZE, (t1 - 5), (t1 + 5));
+  t1 = Trough(data.data(), data.size(), (t1 - 5), (t1 + 5));
   if (t1 < 0) {
     return 0;
   }
 
   int t2 = (t1 * 3) / 2;
-  t2 = Trough(data.data(), DATA_SIZE, (t2 - 5), (t2 + 5));
+  t2 = Trough(data.data(), data.size(), (t2 - 5), (t2 + 5));
   if (t2 < 0) {
     return 0;
   }
 
   int t3 = (t2 * 4) / 3;
-  t3 = Trough(data.data(), DATA_SIZE, (t3 - 4), (t3 + 4));
+  t3 = Trough(data.data(), data.size(), (t3 - 4), (t3 + 4));
   if (t3 < 0) {
     return (60 * 24 * 3) / (t2);
   }
@@ -93,7 +93,7 @@ int Ppg::ProcessHeartRate() {
 // Gets the Index in the Ring Buffer which corresponds to the index, if it was a 0-based Array
 // dataIndex points to the next index to write to, so it is the start of the buffer and the last element is at dataIndex-1
 int Ppg::getRingIndex(int8_t index) {
-  return (index + dataIndex) % Ppg::DATA_SIZE;
+  return (index + dataIndex) % data.size();
 }
 void Ppg::SetOffset(uint16_t offset) {
   this->offset = offset;
@@ -103,5 +103,5 @@ void Ppg::SetOffset(uint16_t offset) {
 void Ppg::Reset() {
   dataIndex = 0;
   // invalidates the current array
-  data[DATA_SIZE - 1] = 0;
+  data[data.size() - 1] = 0;
 }
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index d0e6e13483..6f73237be2 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -10,7 +10,6 @@ namespace Pinetime {
   namespace Controllers {
     class Ppg {
     public:
-      static const uint8_t DATA_SIZE = 200;
       Ppg();
       int8_t Preprocess(float spl);
       int HeartRate();
@@ -20,7 +19,7 @@ namespace Pinetime {
 
     private:
       static const uint8_t UPDATE_HEARTRATE_AFTER = 200;
-      std::array<int8_t, DATA_SIZE> data;
+      std::array<int8_t, 200> data;
       size_t dataIndex = 0;
       float offset;
       Biquad hpf;

From faf2faabea986b1efebb204beab3a4f439008a56 Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Mon, 25 Apr 2022 17:19:40 +0000
Subject: [PATCH 6/7] removed unnecessary parenthesis

---
 src/components/heartrate/Ppg.cpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index fa1a52f7c3..1dc06985f1 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -70,24 +70,24 @@ int Ppg::ProcessHeartRate() {
   }
 
   int t1 = t0 * 2;
-  t1 = Trough(data.data(), data.size(), (t1 - 5), (t1 + 5));
+  t1 = Trough(data.data(), data.size(), t1 - 5, t1 + 5);
   if (t1 < 0) {
     return 0;
   }
 
   int t2 = (t1 * 3) / 2;
-  t2 = Trough(data.data(), data.size(), (t2 - 5), (t2 + 5));
+  t2 = Trough(data.data(), data.size(), t2 - 5, t2 + 5);
   if (t2 < 0) {
     return 0;
   }
 
   int t3 = (t2 * 4) / 3;
-  t3 = Trough(data.data(), data.size(), (t3 - 4), (t3 + 4));
+  t3 = Trough(data.data(), data.size(), t3 - 4, t3 + 4);
   if (t3 < 0) {
-    return (60 * 24 * 3) / (t2);
+    return (60 * 24 * 3) / t2;
   }
 
-  return (60 * 24 * 4) / (t3);
+  return (60 * 24 * 4) / t3;
 }
 
 // Gets the Index in the Ring Buffer which corresponds to the index, if it was a 0-based Array

From 6fb413a85fc1fb9293d22ca667677dd0381dbda0 Mon Sep 17 00:00:00 2001
From: watertrainer <watertrainer42@gmail.com>
Date: Thu, 28 Apr 2022 16:59:36 +0000
Subject: [PATCH 7/7] introduced boolean, if data was filled up at least once

---
 src/components/heartrate/Ppg.cpp | 8 +++++---
 src/components/heartrate/Ppg.h   | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/components/heartrate/Ppg.cpp b/src/components/heartrate/Ppg.cpp
index 1dc06985f1..20849f21a7 100644
--- a/src/components/heartrate/Ppg.cpp
+++ b/src/components/heartrate/Ppg.cpp
@@ -51,11 +51,14 @@ int8_t Ppg::Preprocess(float spl) {
 
   data[dataIndex] = spl_int;
   dataIndex = (dataIndex + 1) % Ppg::data.size();
+  if (dataIndex == 0) {
+    dataReady = true;
+  }
   return spl_int;
 }
 
 int Ppg::HeartRate() {
-  if (data[data.size() - 1] == 0 || dataIndex % Ppg::UPDATE_HEARTRATE_AFTER != 0) {
+  if (!dataReady || dataIndex % Ppg::UPDATE_HEARTRATE_AFTER != 0) {
     return 0;
   }
 
@@ -102,6 +105,5 @@ void Ppg::SetOffset(uint16_t offset) {
 
 void Ppg::Reset() {
   dataIndex = 0;
-  // invalidates the current array
-  data[data.size() - 1] = 0;
+  dataReady = false;
 }
diff --git a/src/components/heartrate/Ppg.h b/src/components/heartrate/Ppg.h
index 6f73237be2..cb7ba5e623 100644
--- a/src/components/heartrate/Ppg.h
+++ b/src/components/heartrate/Ppg.h
@@ -21,6 +21,7 @@ namespace Pinetime {
       static const uint8_t UPDATE_HEARTRATE_AFTER = 200;
       std::array<int8_t, 200> data;
       size_t dataIndex = 0;
+      bool dataReady = false;
       float offset;
       Biquad hpf;
       Ptagc agc;