Diff: MAX31865.h

Revision:

0:ae18c7b91185

Child:

1:5262db31116a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX31865.h	Sun Aug 14 05:09:52 2016 +0000
@@ -0,0 +1,135 @@
+/**************************************************************************
+ * Arduino driver library for the MAX31865.
+ *
+ * Copyright (C) 2015 Ole Wolf <wolf@blazingangles.com>
+ *
+ *
+ * Wire the circuit as follows, assuming that level converters have been
+ * added for the 3.3V signals:
+ *
+ *    Arduino Uno            -->  MAX31865
+ *    ------------------------------------
+ *    CS: any available pin  -->  CS
+ *    MOSI: pin 11           -->  SDI (mandatory for hardware SPI)
+ *    MISO: pin 12           -->  SDO (mandatory for hardware SPI)
+ *    SCK: pin 13            -->  SCLK (mandatory for hardware SPI)
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ **************************************************************************/
+
+
+#ifndef _MAX31865_H
+#define _MAX31865_H
+
+#include <stdint.h>
+#include "mbed.h"
+
+#define MAX31865_FAULT_HIGH_THRESHOLD  ( 1 << 7 )
+#define MAX31865_FAULT_LOW_THRESHOLD   ( 1 << 6 )
+#define MAX31865_FAULT_REFIN           ( 1 << 5 )
+#define MAX31865_FAULT_REFIN_FORCE     ( 1 << 4 )
+#define MAX31865_FAULT_RTDIN_FORCE     ( 1 << 3 )
+#define MAX31865_FAULT_VOLTAGE         ( 1 << 2 )
+
+#define MAX31865_FAULT_DETECTION_NONE      ( 0x00 << 2 )
+#define MAX31865_FAULT_DETECTION_AUTO      ( 0x01 << 2 )
+#define MAX31865_FAULT_DETECTION_MANUAL_1  ( 0x02 << 2 )
+#define MAX31865_FAULT_DETECTION_MANUAL_2  ( 0x03 << 2 )
+
+
+
+/* RTD data, RTD current, and measurement reference
+   voltage. The ITS-90 standard is used; other RTDs
+   may have coefficients defined by the DIN 43760 or
+   the U.S. Industrial (American) standard. */
+#define RTD_A_ITS90         3.9080e-3
+#define RTD_A_USINDUSTRIAL  3.9692e-3
+#define RTD_A_DIN43760      3.9848e-3
+#define RTD_B_ITS90         -5.870e-7
+#define RTD_B_USINDUSTRIAL  -5.8495e-7
+#define RTD_B_DIN43760      -5.8019e-7
+/* RTD coefficient C is required only for temperatures
+   below 0 deg. C.  The selected RTD coefficient set
+   is specified below. */
+#define SELECT_RTD_HELPER(x) x
+#define SELECT_RTD(x) SELECT_RTD_HELPER(x)
+#define RTD_A         SELECT_RTD(RTD_A_ITS90)
+#define RTD_B         SELECT_RTD(RTD_B_ITS90)
+/*
+ * The reference resistor on the hardware; see the MAX31865 datasheet
+ * for details.  The values 400 and 4000 Ohm are recommended values for
+ * the PT100 and PT1000.
+ */
+#define RTD_RREF_PT100         400 /* Ohm */
+#define RTD_RREF_PT1000       4000 /* Ohm */
+/*
+ * The RTD resistance at 0 degrees Celcius.  For the PT100, this is 100 Ohm;
+ * for the PT1000, it is 1000 Ohm.
+ */
+#define RTD_RESISTANCE_PT100   100 /* Ohm */
+#define RTD_RESISTANCE_PT1000 1000 /* Ohm */
+
+#define RTD_ADC_RESOLUTION  ( 1u << 15 ) /* 15 bits */
+
+
+/* See the main (MAX31865.cpp) file for documentation of the class methods. */
+class MAX31865_RTD
+{
+public:
+  enum ptd_type { RTD_PT100, RTD_PT1000 };
+
+  MAX31865_RTD( ptd_type type,PinName mosi, PinName miso, PinName sclk, PinName nss);
+  void configure( bool v_bias, bool conversion_mode, bool one_shot, bool three_wire,
+                  uint8_t fault_cycle, bool fault_clear, bool filter_50hz,
+                  uint16_t low_threshold, uint16_t high_threshold );
+  uint8_t read_all( );
+  double temperature( ) const;
+  uint8_t configuration( ) const { return( (measured_configuration == configuration_control_bits)? configuration_control_bits:measured_configuration); }
+  uint8_t status( ) const { return( measured_status ); }
+  uint16_t low_threshold( ) const { return( measured_low_threshold ); }
+  uint16_t high_threshold( ) const  { return( measured_high_threshold ); }
+  uint16_t raw_resistance( ) const { return( measured_resistance ); }
+  double resistance( ) const
+  {
+    const double rtd_rref =
+      ( this->type == RTD_PT100 ) ? (double)RTD_RREF_PT100 : (double)RTD_RREF_PT1000;
+    return( (double)raw_resistance( ) * rtd_rref / (double)RTD_ADC_RESOLUTION );
+  }
+
+private:
+
+        /*!
+    * SPI Interface
+    */
+    SPI spi; // mosi, miso, sclk
+    DigitalOut nss;
+  /* Our configuration. */
+ // uint8_t  cs_pin;
+  ptd_type type;
+  uint8_t  configuration_control_bits;
+  uint16_t configuration_low_threshold;
+  uint16_t configuration_high_threshold;
+  void reconfigure( );
+
+  /* Values read from the device. */
+  uint8_t  measured_configuration;
+  uint16_t measured_resistance;
+  uint16_t measured_high_threshold;
+  uint16_t measured_low_threshold;
+  uint8_t  measured_status;
+};
+
+#endif /* _MAX31865_H */
+