Cleaned up tach versus rpm

Author: mthorley

include/ArduinoFanControl.h

@@ -14,11 +14,12 @@ class ArduinoFanControl : public FanControl
  virtual RESULT initialise();
  virtual RESULT setPWMForAll(const uint16_t dutyCycle);
  virtual RESULT setPWM(const uint8_t fanid, const uint16_t dutyCycle);
- virtual RESULT getTachCount(const uint8_t fanid, uint16_t& tachCount);
+ virtual RESULT getTachHz(const uint8_t fanid, uint16_t& tachHz);
+ virtual RESULT getRPM(const uint8_t fanid, uint16_t& rpm);
 
 private:
  void measureTach(const uint8_t fanid, unsigned long ms);
- float getTach(const uint8_t fanid, unsigned long ms);
+ float readTach(const uint8_t fanid, unsigned long ms);
 
  uint16_t _pwmPeriod;
 

include/ErrCodes.h

@@ -3,24 +3,27 @@
 
 // err codes
 typedef int RESULT;
-#define RES_OK 0
+#define RES_OK 0
+#define ERR_METHOD_NOT_IMPLEMENTED -1
 
 // I2C for MAX
-#define ERR_BAD_TRANSMISSION -1
-#define ERR_BAD_READ -2
-#define ERR_BAD_PARAM -3
+#define ERR_BAD_TRANSMISSION -11
+#define ERR_BAD_READ -12
+#define ERR_BAD_PARAM -13
 
 // DS18B
-#define ERR_FAILED_TO_READ_TEMP -10
-#define ERR_FAILED_TO_FIND_DEVICE -11
+#define ERR_FAILED_TO_READ_TEMP -20
+#define ERR_FAILED_TO_FIND_DEVICE -21
 
 // Ethernet
-#define ERR_FAILED_TO_GET_IP_FROM_DHCP -20
-#define ERR_NO_ETHERNET_HW -21
-#define ERR_NO_CABLE_DETECTED -22
+#define ERR_FAILED_TO_GET_IP_FROM_DHCP -30
+#define ERR_NO_ETHERNET_HW -31
+#define ERR_NO_CABLE_DETECTED -32
 
 // Fanstate
-#define ERR_FAN_NOT_OPERATIONAL -30
-#define ERR_FAN_TACH -31
+#define ERR_FAN_NOT_OPERATIONAL -40
+#define ERR_FAN_TACH -41
+
+
 
 #endif

include/FanControl.h

@@ -33,7 +33,8 @@ class FanControl
  virtual RESULT initialise() = 0;
  virtual RESULT setPWMForAll(const uint16_t dutyCycle) = 0;
  virtual RESULT setPWM(const uint8_t fanid, const uint16_t dutyCycle) = 0;
- virtual RESULT getTachCount(const uint8_t fanid, uint16_t& tachCount) = 0;
+ virtual RESULT getTachHz(const uint8_t fanid, uint16_t& tachHz) = 0;
+ virtual RESULT getRPM(const uint8_t fanid, uint16_t& rpm) = 0;
 
  const uint8_t getFanCount() const {
  return _fans;

include/MAX31790FanControl.h

@@ -74,6 +74,9 @@ class MAX31790 : public FanControl
  virtual RESULT setPWM(const uint8_t fanid, const uint16_t dutyCycle);
  virtual RESULT getTachCount(const uint8_t fanid, uint16_t& tachCount);
 
+ virtual RESULT getTachHz(const uint8_t fanid, uint16_t& tachHz);
+ virtual RESULT getRPM(const uint8_t fanid, uint16_t& rpm);
+
  RESULT getGlobalConfiguration(GlobalConfig& config);
  //RESULT setGlobalConfiguration(const GlobalConfig& config);
  //RESULT setFanConfigForAll(const FanConfigStruct& config);

src/ArduinoFanControl.cpp

@@ -116,17 +116,22 @@ RESULT ArduinoFanControl::setPWMForAll(const uint16_t dutyCycle)
  return res;
 }
 
-/**
- * Get tachcount per fan
- */
-RESULT ArduinoFanControl::getTachCount(const uint8_t fanid, uint16_t &tachCount)
-{
+RESULT ArduinoFanControl::getTachHz(const uint8_t fanid, uint16_t& tachHz) {
  ASSERT_RANGE_FAN_ID(fanid, getFanCount());
-
+ 
  unsigned long tachTime = 750; //ms
  measureTach(fanid, tachTime);
- float f = getTach(fanid, tachTime);
- tachCount = round(f);
+ float tHz = readTach(fanid, tachTime);
+ tachHz = round(tHz);
+ return RES_OK;
+}
+
+RESULT ArduinoFanControl::getRPM(const uint8_t fanid, uint16_t& rpm) {
+ uint16_t tachHz;
+ getTachHz(fanid, tachHz);
+ // Div 2 since TACH returns 2 pulses per revolution:
+ // https://noctua.at/media/wysiwyg/Noctua_PWM_specifications_white_paper.pdf 
+ rpm = (tachHz * 60.0) / 2;
  return RES_OK;
 }
 
@@ -157,10 +162,11 @@ void ArduinoFanControl::measureTach(const uint8_t fanid, unsigned long msWait)
  } while ((millis() - t1) < msWait);
 }
 
-float ArduinoFanControl::getTach(const uint8_t fanid, unsigned long ms)
+float ArduinoFanControl::readTach(const uint8_t fanid, unsigned long ms)
 {
  // See https://www.pjrc.com/teensy/td_libs_TimerOne.html Interrupt Context Issues
  // noInterrupts();
+
  uint16_t tach = 0;
  switch (fanid) {
  case 1:
@@ -178,9 +184,7 @@ float ArduinoFanControl::getTach(const uint8_t fanid, unsigned long ms)
  }
  // interrupts();
 
- float r = (float)(60 * tach) / ((float)ms / 1000);
- // Divide by 4: since TACH returns 2 pulses per revolution AND 
- // interrupt is CHANGE: H-L and L-H for accuracy.
- // https://noctua.at/media/wysiwyg/Noctua_PWM_specifications_white_paper.pdf 
- return r / 4;
+ // Divide by 2: since interrupt is CHANGE: H-L and L-H for accuracy.
+ float tachHz = (tach * 1000.0 ) / (2 * ms);
+ return tachHz;
 }

src/MAX31790FanControl.cpp

@@ -102,23 +102,28 @@ RESULT MAX31790::setPWMForAll(const uint16_t dutyCycle)
 }
 
 /**
- * GetTachCount per fan
+ * GetTachHz per fan
  */
-RESULT MAX31790::getTachCount(const uint8_t fanid, uint16_t &tachCount)
-{
+RESULT MAX31790::getTachHz(const uint8_t fanid, uint16_t& tachHz) {
+
  ASSERT_RANGE_FAN_ID(fanid, getFanCount());
  uint8_t buffer[2];
  RESULT res = readBytes(TACH_COUNT(fanid), 2, &buffer[0]);
  if (res != RES_OK)
  return res;
 
- tachCount = buffer[0];
- tachCount = tachCount << 8;
- tachCount |= buffer[1];
- tachCount = tachCount >> 5;
+ tachHz = buffer[0];
+ tachHz = tachHz << 8;
+ tachHz |= buffer[1];
+ tachHz = tachHz >> 5;
+
  return RES_OK;
 }
 
+RESULT MAX31790::getRPM(const uint8_t fanid, uint16_t& rpm) {
+ return ERR_METHOD_NOT_IMPLEMENTED;
+}
+
 /**
  * Scan all i2c devices between 1 and 127.
  */

src/OLEDDisplay.cpp

@@ -63,7 +63,7 @@ void OLEDDisplay::internalRender(RackState_t&rs, const NetworkState_t& ns) {
  OLED_Colour LINE_COL = DARKGRAY;
 
  _oled.drawString(x, 128-18, F("TEMP C"), WHITE, BLACK);
- _oled.drawString(x, y-1-18, F("TACH %"), WHITE, BLACK);
+ _oled.drawString(x, y-1-18, F("RPM %"), WHITE, BLACK);
  _oled.drawCircle(38, 128-4, 2, WHITE); // degree symbol
  _oled.drawLine(x+65, 0, x+65, 128, LINE_COL);
  _oled.drawLine(0, y-2, 128, y-2, LINE_COL);
@@ -152,7 +152,8 @@ uint8_t OLEDDisplay::getPercentageRPM(const FanState_t& fan) const {
  else if (fan.rpm > fan.maxRpm) // maybe due to "noise" on tach pin
  return 100;
  else 
- return round(((float)(fan.rpm - fan.minRpm) / (fan.maxRpm - fan.minRpm)) * 100.0);
+ //return round(((float)(fan.rpm - fan.minRpm) / (fan.maxRpm - fan.minRpm)) * 100.0);
+ return round( ((float)fan.rpm / fan.maxRpm) * 100 );
 }
 
 void OLEDDisplay::drawPercentage(int x, int y, uint8_t pc) {

src/RackTempController.cpp

@@ -73,8 +73,8 @@ RESULT RackTempController::checkRpm(FanState_t& fs) const {
  }
 
  // is the fan within expected RPM variance given dutyCycle?
- uint16_t expectedRpm = round((float)(fs.maxRpm - fs.minRpm) * ((float)fs.pwm/100)) + fs.minRpm;
-
+ uint16_t expectedRpm = round( fs.maxRpm * (float)fs.pwm/100 );
+ 
  uint16_t minExpectedRpm = round(expectedRpm - expectedRpm * _rpmVariance);
  uint16_t maxExpectedRpm = round(expectedRpm + expectedRpm * _rpmVariance);
  if (fs.rpm < minExpectedRpm || fs.rpm > maxExpectedRpm) {
@@ -106,7 +106,7 @@ void RackTempController::adjustFanSpeeds(RackState_t& rs) {
  uint8_t dutyCycle = 50;
  for (auto it = rs.thermos.begin(); it != rs.thermos.end(); it++) {
  Temperature_t& thermo = it->second;
- if (thermo.tempCelsuis > 20) {
+ if (thermo.tempCelsuis > 22) {
  dutyCycle = 100;
  }
  }
@@ -122,20 +122,20 @@ void RackTempController::adjustFanSpeeds(RackState_t& rs) {
 
 /**
  * Get tach/rpm for all fans
- * Delay of 750ms per fan within getTachCount()
+ * Delay of 750ms per fan within getRPM()
  */
 void RackTempController::readFanSpeeds(Fans_t& fans) {
 
- uint16_t tachCount = 0;
-
+ uint16_t rpm = 0;
+ 
  Log.notice(F("Reading fan rpms"));
 
  for (auto it = fans.begin(); it != fans.end(); it++) {
- _fanControl.getTachCount(it->first, tachCount);
- it->second.rpm = tachCount;
- Log.notice(F("Fan %s tach rpm - %d"), it->second.position.c_str(), tachCount);
+ _fanControl.getRPM(it->first, rpm);
+ it->second.rpm = rpm;
+ Log.notice(F("Fan %s rpm - %d"), it->second.position.c_str(), rpm);
  }
-}; 
+};
 
 void RackTempController::readTempStates(Thermos_t& thermos) {