Revision 2:832cb4376d2a, committed 2017-03-29

Comitter:

sk398

Date:

Wed Mar 29 17:55:38 2017 +0000

Parent:

1:444546e8cd20

Child:

3:c6aad2355a40

Commit message:

Working version on the NUCLEO-F446RE board

Changed in this revision

--- a/MCP9803/MCP9803.cpp	Wed Mar 29 12:20:34 2017 +0000
+++ b/MCP9803/MCP9803.cpp	Wed Mar 29 17:55:38 2017 +0000
@@ -30,26 +30,115 @@
     inBuffer = (char *)malloc(1);
 }
 
-int MCP9803::ConfigSensor()
+
+
+int MCP9803::ConfigSensor(  int shutdown, int comp_int, int alert_polarity,
+                            int fault_guide, int adc_res, int one_shot)
 {
+    // Assign passed values to struct members
+    CONFIG_REG_VALUE.CONFIG_BITS.SHUTDOWN_BIT = shutdown;
+    CONFIG_REG_VALUE.CONFIG_BITS.COMP_INT_BIT = comp_int;
+    CONFIG_REG_VALUE.CONFIG_BITS.ALERT_POLARITY_BIT = alert_polarity;
+    CONFIG_REG_VALUE.CONFIG_BITS.FAULT_QUEUE = fault_guide;
+    CONFIG_REG_VALUE.CONFIG_BITS.ADC_RES = adc_res;
+    CONFIG_REG_VALUE.CONFIG_BITS.ONE_SHOT = one_shot;
+
+    // Generate Command to send to MCP9803
+    // <Pointer to Config Register, CONFIG Register Value>
+    char dataOut[] = {CONFIG_REG_POINT, CONFIG_REG_VALUE.CONFIG_VALUE}; 
+    
+    // Write Bytes to MCP9803
+    int writeReturn = I2C_Write(dataOut,CONFIG_CMD_LENGTH);
+    
+    // Check on return status of the Write command
+    if(writeReturn != 0)
+    {
+        // Failure
+        return FAILURE;     
+    }
+    else
+    {
+        // Success
+        return SUCCESS;   
+    }
+}
+
+
+int MCP9803::RawTempValue()
+{
+    // Set MCP9803 Register Pointer to point to Temperature Register
+    I2C_Write((char *)TEMP_REG_POINT,1);
+    
+    // Read TEMP_DATA_LENGTH bytes into temp buffer
+    char *tempInBuffer = I2C_Read(TEMP_DATA_LENGTH);
     
+    // Convert tempInBuffer to rawData
+    // Shift first Byte (MSB) up by 8, OR with second Byte (LSB)
+    // Then shift Result down by 4
+    int rawData = ((*(tempInBuffer)<<8|*(tempInBuffer+1))>>4);
+
+    // 
+    return rawData;
+}
+
+
+
+float MCP9803::FormattedTempValue(int format)
+{
+    // Get Raw Temp Value
+    int tempData = RawTempValue();
     
-    return 0;   
+    if(tempData == READ_TEMP_FAIL_VALUE)
+    {
+        return READ_TEMP_FAIL_ERROR;
+    }
+    
+    // Check and convert if 2's Complement
+    if(tempData > 2047)
+    {
+        tempData -= 4096;
+    }
+    
+    // Return formatted data based on format
+    switch(format)
+    {
+        // Return celcius value of temperature
+        case CELCIUS:
+            return (RAW_TO_C*tempData);
+
+        // Return farenheit value of temperature
+        case FARENHEIT:
+            return ((RAW_TO_C*tempData)*C_F_1)+C_F_2;
+
+        // Return Kelvin value of temperature
+        case KELVIN:
+            return ((RAW_TO_C*tempData)+C_TO_F);
+ 
+        // If input is invalid, return value outwith range
+        // of other format options
+        default:
+            return FORMAT_FAIL;
+    }
 }
 
 
 
 int MCP9803::I2C_Write(char *dataOut,int dataLen)
 {    
+    // Define Char Buffer of length dataLen
     char outBuffer[dataLen];
     
+    // Populate Buffer with dataOut
     for(int i=0 ; i<dataLen ; i++)
     {
         outBuffer[i] = *(dataOut+i);
     }
     
+    // Write out to I2C Bus
     int sendStatus = _I2C -> write(chipAddress,outBuffer,dataLen,0);
     
+    // Return success value of the Write
+    // Returns 0 for Success, 1 for failure
     return sendStatus;
 }
 
@@ -57,50 +146,47 @@
 
 char *MCP9803::I2C_Read(int dataLen)
 {
+    // Reallocate memory to dataLen length expected for inBuffer
     setBufferSize(dataLen);
     
+    // Read from the I2C Bus
     int receiveStatus = _I2C -> read(chipAddress,inBuffer,dataLen,0);
    
+   // Check success value
+   // If receiveStatus != 0, indicates failure
     if(receiveStatus != 0)
     {
+        // Generate unique command to indicate failure, based on number of 
+        // expected incoming bytes
         for(int i = 0; i < dataLen; i++)
         {
+            // For even indexes of inBuffer
             if(i % 2 == 0)
             {
-                inBuffer[i] = 0xFF;
+                inBuffer[i] = FAIL_EVEN_VALUE;
             }
+            // For odd indexes of inBuffer
             else
             {
-                inBuffer[i] = 0x00;
+                inBuffer[i] = FAIL_ODD_VALUE;
             }
-            printf("Buffer Value = %02x",inBuffer[i]);
         }
+        // Return unique error command
         return inBuffer;
     }
-    
     else
     {
+        // Return Buffer contents based on successful read
         return inBuffer;
     }
-
 }
     
 void MCP9803::setBufferSize(int dataLen)
 {
+    // Reallocate memory for the inBuffer to account for differing lengths of 
+    // data which can be read in
     inBuffer = (char *)realloc(inBuffer, dataLen);
 }
-    
-char *MCP9803::getBuffer()
-{    
-    
-}
-
-void MCP9803::setBuffer()
-{
-    
-}
-  
-    
 
 /********************************************************************************************
 

--- a/MCP9803/MCP9803.h	Wed Mar 29 12:20:34 2017 +0000
+++ b/MCP9803/MCP9803.h	Wed Mar 29 17:55:38 2017 +0000
@@ -19,6 +19,34 @@
 
 #include "mbed.h"
 
+#define SUCCESS                 0
+#define FAILURE                 1
+
+#define FAIL_EVEN_VALUE         0xFF
+#define FAIL_ODD_VALUE          0x00
+
+#define TEMP_REG_POINT          0x00
+#define CONFIG_REG_POINT        0x01
+#define TEMP_HYST_POINT         0x02
+#define TEMP_LIM_SET_POINT      0x03
+
+#define CONFIG_CMD_LENGTH       2
+#define TEMP_DATA_LENGTH        2
+
+#define READ_TEMP_FAIL_VALUE    0x0FF0
+#define READ_TEMP_FAIL_ERROR    -2000
+
+#define CELCIUS                 0x01
+#define FARENHEIT               0x02
+#define KELVIN                  0x03
+#define FORMAT_FAIL             -1000
+
+#define RAW_TO_C                0.0625
+#define C_F_1                   1.8
+#define C_F_2                   32
+#define C_TO_F                  273.15
+
+
 union CONFIG_REG
 {
     struct
@@ -39,9 +67,12 @@
     
 public:
     MCP9803(PinName sda, PinName scl, int Address, int frequency);
-    int ConfigSensor();
-    int I2C_Write(char *dataOut,int dataLen);
-    char *I2C_Read(int dataLen);
+    int ConfigSensor(   int shutdown, int comp_int, int alert_polarity,
+                        int fault_guide, int adc_res, int one_shot);
+
+    
+    int RawTempValue();
+    float FormattedTempValue(int format);
 
 private:
     I2C *_I2C;
@@ -50,13 +81,10 @@
     
     char *inBuffer;
     
-    void setBufferSize(int dataLen);
-    char *getBuffer();
-    void setBuffer();   
+    int I2C_Write(char *dataOut,int dataLen);
+    char *I2C_Read(int dataLen);
+    void setBufferSize(int dataLen); 
 
-protected:
-  
-    
 };
 
 #endif
\ No newline at end of file

--- a/main.cpp	Wed Mar 29 12:20:34 2017 +0000
+++ b/main.cpp	Wed Mar 29 17:55:38 2017 +0000
@@ -5,44 +5,24 @@
 
 int main()
 {
-    char data[2];
+    // Example of how to Configure Sensor
     
-    data[0] = 0x01;
-    data[1] = 0x72;
-    
-    printf("Write Return Value = %d\r\n",TempSensor.I2C_Write(data,2));
-    
-    data[0] = 0x01;
+    int configSuccess = TempSensor.ConfigSensor(0x00,0x01,0x00,0x02,0x03,0x00);
     
-    printf("Write Return Value = %d\r\n",TempSensor.I2C_Write(data,1));   
-    
-    TempSensor.I2C_Read(1);
-    
-    data[0] = 0x00;
-    TempSensor.I2C_Write(data,1);
-    
-    int len = 2;
-    char *buffer = TempSensor.I2C_Read(len);
-    
-    char inBuffer[len];
+    // Print value returned from ConfigSensor
+    // 0 indicates success, 1 indicates failure
+    printf("CONFIG Success = %d\r\n\r\n",configSuccess);
     
-    for(int i = 0; i < len; i++)
-    {
-        inBuffer[i] = *(buffer+i);
-    }
-    
-    int dat = (((inBuffer[0] << 8) | inBuffer[1])>>4);
-    
-    printf("data value = %04x\r\n",dat);
+    // Print raw temp value
+    // Anything other than 0x0FF0 indicates success
+    printf("Temp Raw = %04x\r\n",TempSensor.RawTempValue());
     
-    if(dat > 2047)
-    {
-        dat -= 4096;
-    }
-    
-    float tempC = 0.0625*dat;
-    printf("Temp C = %f\r\n\r\n",tempC);   
-    
-    
-    
+    // Print converted temp values
+    // Anything other than -2000.000 indicates success
+    printf("Temp C = %f\r\n",TempSensor.FormattedTempValue(CELCIUS));
+    printf("Temp F = %f\r\n",TempSensor.FormattedTempValue(FARENHEIT));
+    printf("Temp K = %f\r\n",TempSensor.FormattedTempValue(KELVIN));
+   
+   // Example of failure from sending wrong format
+   printf("Temp ? = %f\r\n",TempSensor.FormattedTempValue(0x0F));
 }
\ No newline at end of file