Merge pull request #13 from mikeysklar/setAmbientResolution

setAmbientResolution()

Author: ladyada

Adafruit_MCP9600.cpp

@@ -363,3 +363,17 @@ uint8_t Adafruit_MCP9600::getStatus(void) {
 
   return status.read();
 }
+
+/**************************************************************************/
+/*!
+    @brief  Sets the resolution for ambient (cold junction) temperature readings
+    @param  res_value Ambient_Resolution enum value to set resolution
+*/
+/**************************************************************************/
+void Adafruit_MCP9600::setAmbientResolution(Ambient_Resolution res_value) {
+  uint8_t config;
+  _config_reg->read(&config, 1);        // Read the current configuration
+  config &= ~0xC0;                      // Clear existing resolution bits
+  config |= ((~res_value & 0x03) << 6); // Set inverted resolution bits
+  _config_reg->write(config);           // Write back the configuration
+}

Adafruit_MCP9600.h

@@ -64,6 +64,14 @@ typedef enum _resolution {
   MCP9600_ADCRESOLUTION_12,
 } MCP9600_ADCResolution;
 
+/*! The possible Ambient resolutions */
+typedef enum {
+  RES_ZERO_POINT_25 = 0b00,   ///< 0.25°C
+  RES_ZERO_POINT_125 = 0b01,  ///< 0.125°C
+  RES_ZERO_POINT_0625 = 0b10, ///< 0.0625°C
+  RES_ZERO_POINT_03125 = 0b11 ///< 0.03125°C
+} Ambient_Resolution;
+
 /**************************************************************************/
 /*!
     @brief  MCP9600 driver.
@@ -91,6 +99,8 @@ class Adafruit_MCP9600 {
   MCP9600_ADCResolution getADCresolution(void);
   int32_t readADC(void);
 
+  void setAmbientResolution(Ambient_Resolution res_value);
+
   void setAlertTemperature(uint8_t alert, float temp);
   float getAlertTemperature(uint8_t alert);
   void configureAlert(uint8_t alert, bool enabled, bool rising,

examples/mcp9600_test/mcp9600_test.ino

@@ -7,22 +7,35 @@
 
 Adafruit_MCP9600 mcp;
 
+/* Set and print ambient resolution */
+Ambient_Resolution ambientRes = RES_ZERO_POINT_0625;
+
 void setup()
 {
-    Serial.begin(115200);
-    while (!Serial) {
-      delay(10);
-    }
-    Serial.println("MCP9600 HW test");
+  Serial.begin(115200);
+  while (!Serial) {
+    delay(10);
+  }
+  Serial.println("MCP9600 HW test");
 
-    /* Initialise the driver with I2C_ADDRESS and the default I2C bus. */
-    if (! mcp.begin(I2C_ADDRESS)) {
-        Serial.println("Sensor not found. Check wiring!");
-        while (1);
-    }
+   /* Initialise the driver with I2C_ADDRESS and the default I2C bus. */
+  if (! mcp.begin(I2C_ADDRESS)) {
+    Serial.println("Sensor not found. Check wiring!");
+    while (1);
+  }
 
   Serial.println("Found MCP9600!");
 
+  /* Set and print ambient resolution */
+  mcp.setAmbientResolution(ambientRes);
+  Serial.print("Ambient Resolution set to: ");
+  switch (ambientRes) {
+    case RES_ZERO_POINT_25:    Serial.println("0.25°C"); break;
+    case RES_ZERO_POINT_125:   Serial.println("0.125°C"); break;
+    case RES_ZERO_POINT_0625:  Serial.println("0.0625°C"); break;
+    case RES_ZERO_POINT_03125: Serial.println("0.03125°C"); break;
+  }
+
   mcp.setADCresolution(MCP9600_ADCRESOLUTION_18);
   Serial.print("ADC resolution set to ");
   switch (mcp.getADCresolution()) {