Diff: DS1721.cpp

Revision:

1:4fd830a97574

Child:

2:22dbeccb82be

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1721.cpp	Thu May 02 17:12:06 2013 +0000
@@ -0,0 +1,258 @@
+/***********************************************************************************
+ * @file        ds1721.cpp
+ * @brief       Source file, enabling communication to/from the Dallas Semiconductor 
+ *              (Maxim Integrated) DS1721 2-Wire Digital Theremometer and Thermostat.
+ * @version     1.00
+ * @date        04/29/2013
+ * 
+ * @author      Cameron Haegle
+ * @company     Digi International
+ * @copyright   
+ * 
+ * @limitations 
+ *
+ * 
+ **********************************************************************************/
+
+
+#include "ds1721.h"
+
+/**
+ *
+ **/
+DS1721::DS1721(PinName sda, PinName scl, int addr) : m_i2c(sda, scl) , m_addr(addr)
+{    
+     _resolution = RES_9_BIT;
+     _polarity   = POLARITY_ACTIVE_HIGH;
+     _mode   = CONV_FOREVER;
+     _num_read = 1;
+     
+     setConfig(_resolution | _polarity | _one_shot);
+}
+
+/**
+ *
+ **/
+DS1721::DS1721(PinName sda, PinName scl, int addr, int resolution, int polarity, int mode) 
+        : m_i2c(sda, scl) , m_addr(addr) , _resolution(resolution) , _polarity(polarity) , _one_shot(one_shot)
+{    
+    _num_read = 1;     
+    setConfig(_resolution | _polarity | _mode);
+}
+
+/**
+ * deconstructor
+ *
+ **/
+DS1721::~DS1721(void) 
+{ 
+}
+
+
+/**
+ *
+ **/
+int DS1721::setConfig(int config)
+{
+    char cmd[2];
+    cmd[0] = CMD_ACCESS_CFG;
+    cmd[1] = (config & 0xFF);
+    
+    if(!m_i2c.write(m_addr, cmd, 2) != 0)
+    {        
+        return 0;
+    }    
+    return 1;
+}
+
+/**
+ *
+ **/
+int DS1721::getConfig(int* config)
+{
+    char cmd[2];
+    
+    cmd[0] = CMD_ACCESS_CFG;      // 0xAC
+    if(m_i2c.write(m_addr, cmd, 1) != 0)
+    {       
+        return 0;
+    }
+    //Delay(RW_DELAY);    
+    if((m_i2c.read(m_addr, cmd, 1)) != 0)
+    {      
+        return 0;
+    }      
+    *config = cmd[0];
+    return 1;
+}
+ 
+
+int DS1721::getTemp(void)
+{
+    char cmd[3];
+   
+    cmd[0] = CMD_READ_TEMP;
+    
+    // if this is the first read, since power up, perform the read twice
+    // this eliminate  an erroneous initial read.
+    do
+    {        
+        if((m_i2c.write(m_addr, cmd, 1)) != 0)
+        {       
+            return 0;
+        }    
+        //Delay(RW_DELAY);
+        // read 1 byte, ignoring fractional portion of temperature
+        if((m_i2c.read(m_addr, cmd, 2)) != 0)
+        {
+            return 0;
+        }
+        _num_read--;
+    }while(_num_read);
+    
+    _num_read = 1;
+    
+    return cmd[0];
+}
+
+
+/**
+ *
+ *
+ **/
+int DS1721::setPolarity(int polarity)
+{
+    _polarity = polarity;
+    return setConfig(_resolution | _polarity | _one_shot);
+}
+
+/**
+ *
+ *
+ **/
+int DS1721::getPolarity(void)
+{
+    int config;    
+    getConfig(&config);
+    return ((config & (1<<1)) ? 1: 0);
+}
+
+
+/**
+ *
+ *
+ **/
+int DS1721::startConversion(void)
+{
+   char cmd[1];
+    
+    cmd[0] = CMD_START_CONVT; // 0x51
+    
+    if((m_i2c.write(m_addr, cmd, 1)) != 1)
+    {      
+        return 0;
+    }  
+    return 1;
+}
+
+/**
+ *
+ *
+ **/
+int DS1721::stopConversion(void)
+{
+    char cmd[1];
+    
+    cmd[0] = CMD_STOP_CONVT; // 0x51
+    
+    if((m_i2c.write(m_addr, cmd, 1)) != 0)
+    {       
+        return 0;
+    }  
+    return 1;
+}
+
+/**
+ *
+ **/
+int DS1721::getLowSetpoint(void)
+{
+    char cmd[4];
+        
+    cmd[0] = CMD_ACCESS_TL;
+    if((m_i2c.write(m_addr, cmd, 1)) != 0)
+    {     
+        //return FALSE;
+    }
+    //Delay(RW_DELAY);
+    
+    // read back TL msb & lsb bytes
+    if((m_i2c.read(m_addr, cmd, 2)) != 0)
+    {       
+        return 0;
+    }    
+    _tl = (cmd[0] & 0xFF);  
+    return _tl;
+}
+
+/**
+ *
+ **/
+int DS1721::setLowSetpoint(int newSp)
+{
+    char cmd[3];
+    
+    _tl = newSp;
+    
+    cmd[0] = CMD_ACCESS_TL;
+    cmd[1] = _tl;         // temp MSB
+    cmd[2] = 0x80;        // temp LSB (+/-0.5)
+
+    if((m_i2c.write(m_addr, cmd, 3)) != 0)
+    {       
+        return 0;
+    }
+    return 1;
+}
+
+/**
+ *
+ **/
+int DS1721::getHighSetpoint(void)
+{
+    char cmd[3];
+        
+    cmd[0] = CMD_ACCESS_TH;
+    if((m_i2c.write(m_addr, cmd, 1)) != 0)
+    {
+        //return 0;
+    }
+    //Delay(RW_DELAY);
+    // read back TL msb & lsb bytes
+    if((m_i2c.read(m_addr, cmd, 2)) != 0)
+    {
+        //return 0;
+    }    
+    _th = (cmd[0] & 0xFF);
+    return _th; 
+}
+
+/**
+ *
+ **/
+int DS1721::setHighSetpoint(int newSp)
+{
+    char cmd[3];
+    
+    _th = newSp;
+
+    cmd[0] = CMD_ACCESS_TH;
+    cmd[1] = _th;           // temp MSB
+    cmd[2] = 0x00;          // temp LSB
+
+    if((m_i2c.write(m_addr, cmd, 3)) != 0)
+    {      
+        return 0;
+    }
+    return 1;
+}