From dcae9763729063f9ebf06c75b406c3c3037133a8 Mon Sep 17 00:00:00 2001
From: doudar <anthonydoud97@gmail.com>
Date: Tue, 4 Oct 2022 22:28:02 -0500
Subject: [PATCH] Simplified CAD compensation in Powertable

---
 CHANGELOG.md       |  4 +++-
 src/BLE_Server.cpp |  2 +-
 src/ERG_Mode.cpp   | 23 ++++++-----------------
 3 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index df16746b..00eaee9d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,8 +20,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed HR in the hidden btsimulator.html
 - Enabled CORS for doudar/StreamFit.
 - Re-arranged index.html. 
-- restored link to bluetooth scanner
+- restored link to bluetooth scanner.
 - Reverted conditional variable initialization in powertable lookup function.
+- Simplified cadence compensation in powertable lookup.
+- Fixed issue where you couldn't set a ERG target less than 50W (MIN_WATTS wasn't being respected.) 
 
 ### Hardware
 - Ultra Short Direct Mount case for use on bikes with limited space between knob and head tube
diff --git a/src/BLE_Server.cpp b/src/BLE_Server.cpp
index 0a9a01b5..e901d7e0 100644
--- a/src/BLE_Server.cpp
+++ b/src/BLE_Server.cpp
@@ -318,7 +318,7 @@ void MyServerCallbacks::onDisconnect(BLEServer *pServer) {
 void MyCallbacks::onWrite(BLECharacteristic *pCharacteristic) { FTMSWrite = pCharacteristic->getValue(); }
 
 void MyCallbacks::onSubscribe(NimBLECharacteristic *pCharacteristic, ble_gap_conn_desc *desc, uint16_t subValue) {
-  String str        = "Client ID: ";
+  String str       = "Client ID: ";
   NimBLEUUID pUUID = pCharacteristic->getUUID();
   str += desc->conn_handle;
   str += " Address: ";
diff --git a/src/ERG_Mode.cpp b/src/ERG_Mode.cpp
index a828cfed..bc911bc6 100644
--- a/src/ERG_Mode.cpp
+++ b/src/ERG_Mode.cpp
@@ -279,20 +279,9 @@ int32_t PowerTable::lookup(int watts, int cad) {
     return (RETURN_ERROR);
   }
 
-  // @MarkusSchneider's data shows a linear relationship between CAD and Watts for a given resistance level.
-  // It looks like for every 20 CAD increase there is ~50w increase in power. This may need to be adjusted later
-  // as higher resistance levels have a steeper slope (bigger increase in power/cad) than low resistance levels.
+  // Cadence Adjustment
   float averageCAD = (below.cad + above.cad) / 2;
-  float deltaCAD   = abs(averageCAD - cad);
-
-  if (deltaCAD > 5) {
-    if (cad > averageCAD) {  // cad is higher than the table so we need to target a lower wattage (and targetPosition)
-      watts -= (deltaCAD / 20) * 50;
-    }
-    if (cad < averageCAD) {  // cad is lower than the table so we need to target a higher wattage (and targetPosition)
-      watts += (deltaCAD / 20) * 50;
-    }
-  }
+  watts            = ((watts * 2) * (averageCAD / (cad + 1)) / 2);
   // actual interpolation
   int32_t rTargetPosition = below.targetPosition + ((watts - below.power) / (above.power - below.power)) * (above.targetPosition - below.targetPosition);
 
@@ -355,10 +344,10 @@ void ErgMode::computErg() {
     return;
   }
 
-  // set minimum SetPoint to 50 watt if trainer sends setpoints lower than 50 watt.
-  if (newSetPoint < 50) {
+  // set minimum SetPoint to MIN_WATTS if app sends setpoints lower than MIN_WATTS.
+  if (newSetPoint < MIN_WATTS) {
     SS2K_LOG(ERG_MODE_LOG_TAG, "ERG Target Below Minumum Value.");
-    newSetPoint = 50;
+    newSetPoint = MIN_WATTS;
   }
 
   bool isUserSpinning = this->_userIsSpinning(newCadence, currentIncline);
@@ -394,7 +383,7 @@ void ErgMode::_setPointChangeState(int newSetPoint, int newCadence, Measurement&
   int i = 0;
   while (rtConfig.getTargetIncline() != rtConfig.getCurrentIncline()) {  // wait while the knob moves to target position.
     vTaskDelay(100 / portTICK_PERIOD_MS);
-    if (i > 50) {  // failsafe for infinate loop
+    if (i > 50) {  // failsafe for infinite loop
       SS2K_LOG(ERG_MODE_LOG_TAG, "Stepper didn't reach target position");
       break;
     }