Version 1.19beta6

Refactored temperatyure sensor code
Refactored fan control code
Support invisible axes (M584 P parameter)
Supprt user-defined virtual heaters
Support heater names
Support proportional thermostatic fan control
Fix G10 retraction command
Removed delta probe code

1 files changed, 59 insertions, 0 deletions

diff --git a/src/Heating/Sensors/Thermistor.h b/src/Heating/Sensors/Thermistor.h
new file mode 100644
index 00000000..1c002c34
--- /dev/null
+++ b/src/Heating/Sensors/Thermistor.h
@@ -0,0 +1,59 @@
+/*
+ * Thermistor.h
+ *
+ *  Created on: 10 Nov 2016
+ *      Author: David
+ */
+
+#ifndef SRC_HEATING_THERMISTOR_H_
+#define SRC_HEATING_THERMISTOR_H_
+
+#include "TemperatureSensor.h"
+
+// The Steinhart-Hart equation for thermistor resistance is:
+// 1/T = A + B ln(R) + C [ln(R)]^3
+//
+// The simplified (beta) equation assumes C=0 and is:
+// 1/T = A + (1/Beta) ln(R)
+//
+// The parameters that can be configured in RRF are R25 (the resistance at 25C), Beta, and optionally C.
+
+class Thermistor : public TemperatureSensor
+{
+public:
+	Thermistor(unsigned int channel);										// create an instance with default values
+	bool Configure(unsigned int mCode, unsigned int heater, GCodeBuffer& gb, StringRef& reply, bool& error) override; // configure the sensor from M305 parameters
+	void Init() override;
+	TemperatureError GetTemperature(float& t) override;
+
+private:
+	float CalcTemperature(int32_t adcReading) const;						// calculate temperature from an ADC reading in the range 0..1
+	int32_t CalcAdcReading(float temperature) const;						// calculate expected ADC reading at a particular temperature
+
+	float GetR25() const { return r25; }
+	float GetBeta() const { return beta; }
+	float GetShc() const { return shC; }
+	float GetSeriesR() const { return seriesR; }
+	int8_t GetLowOffset() const { return adcLowOffset; }
+	int8_t GetHighOffset() const { return adcHighOffset; }
+
+	void SetLowOffset(int8_t p_offset) { adcLowOffset = p_offset; }
+	void SetHighOffset(int8_t p_offset) { adcHighOffset = p_offset; }
+
+	// For the theory behind ADC oversampling, see http://www.atmel.com/Images/doc8003.pdf
+	static const unsigned int AdcOversampleBits = 1	;						// we use 1-bit oversampling
+
+	void CalcDerivedParameters();											// calculate shA and shB
+
+	// The following are configurable parameters
+	float r25, beta, shC, seriesR;											// parameters declared in the M305 command
+	int8_t adcLowOffset, adcHighOffset;										// ADC low and high end offsets
+
+	// The following are derived from the configurable parameters
+	float shA, shB;															// derived parameters
+
+	static const unsigned int AdcBits = 12;									// the ADCs in the SAM processors are 12-bit
+	static const int32_t AdcRange = 1 << (AdcBits + AdcOversampleBits);		// The readings we pass in should be in range 0..(AdcRange - 1)
+};
+
+#endif /* SRC_HEATING_THERMISTOR_H_ */