Diff: mpl3115a2.cpp

Revision:

0:6bba2efea51e

Child:

1:3cd1f21925e8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mpl3115a2.cpp	Wed Mar 18 01:00:53 2015 +0000
@@ -0,0 +1,237 @@
+#include "mpl3115a2.h"
+ 
+#define MPL3115A_I2C_ADDRESS                        0xc0  //0x60
+
+
+MPL3115A2::MPL3115A2(I2C& r) : m_i2c(r)
+{
+}
+
+MPL3115A2::~MPL3115A2()
+{
+}
+
+void MPL3115A2::init()
+{
+    uint8_t regVal;
+
+    //MPL3115Reset( );
+    write(CTRL_REG1, 4);
+    wait(0.05);
+    
+    do
+    {   // Wait for the RST bit to clear 
+        regVal = read( CTRL_REG1);
+        //printf("ctrl_reg1:%02x\n", regVal);
+    } while( regVal );
+   
+    write( PT_DATA_CFG_REG, 0x07 ); // Enable data flags 
+    write( CTRL_REG3, 0x11 );       // Open drain, active low interrupts 
+    write( CTRL_REG4, 0x80 );       // Enable DRDY interrupt 
+    write( CTRL_REG5, 0x00 );       // DRDY interrupt routed to INT2 - PTD3 
+    write( CTRL_REG1, 0xA9 );       // Active altitude mode, OSR = 32    
+                                               
+    write( OFF_H_REG, 0xB0 );       // Altitude data offset
+    
+    SetModeActive( );
+}
+
+void MPL3115A2::SetModeActive( )
+{
+    uint8_t val = read(CTRL_REG1);
+    val |= 1;   // set SBYB
+    write(CTRL_REG1, val);
+}
+
+void MPL3115A2::SetModeStandby( )
+{
+    uint8_t val = read(CTRL_REG1);
+    val &= ~1;   // clear SBYB
+    write(CTRL_REG1, val);
+}
+
+void MPL3115A2::write(uint8_t a, uint8_t d)
+{
+    char cmd[2];
+    
+    cmd[0] = a;
+    cmd[1] = d;
+
+    if (m_i2c.write(MPL3115A_I2C_ADDRESS, cmd, 2))
+        printf("write-fail %02x %02x\n", cmd[0], cmd[1]);
+}
+
+uint8_t MPL3115A2::read(uint8_t a)
+{
+    char cmd[2];
+    
+    cmd[0] = a;
+    if (m_i2c.write(MPL3115A_I2C_ADDRESS, cmd, 1, true))
+        printf("write-fail %02x\n", cmd[0]);
+    if (m_i2c.read(MPL3115A_I2C_ADDRESS, cmd, 1))
+        printf("read-fail\n");
+    //printf("MPL3115::try_read: %x\n", cmd[0]);        
+    return cmd[0];
+}
+
+/*void MPL3115A2::try_read()
+{
+    char cmd[2];
+    
+    cmd[0] = MPL3115_ID;
+    if (m_i2c.write(MPL3115A_I2C_ADDRESS, cmd, 1, true))
+        printf("write-fail try_read\n");
+    if (m_i2c.read(MPL3115A_I2C_ADDRESS, cmd, 1))
+        printf("read-fail\n");
+    printf("MPL3115::try_read: %x\n", cmd[0]);        
+}*/
+
+float MPL3115A2::ReadAltitude( void )
+{
+    uint8_t counter = 0;
+    uint8_t val = 0;
+    uint8_t msb = 0, csb = 0, lsb = 0;
+    float decimal = 0;
+
+    /*if( MPL3115Initialized == false )
+    {
+        return 0;
+    }*/
+
+    SetModeAltimeter( );
+    ToggleOneShot( );
+
+    while( ( val & 0x04 ) != 0x04 )
+    {    
+        val = read( STATUS_REG);
+        wait(0.01); //DelayMs( 10 );
+        counter++;
+    
+        if( counter > 20 )
+        {    
+            //MPL3115Initialized = false;
+            init( );
+            SetModeAltimeter( );
+            ToggleOneShot( );
+            counter = 0;
+            while( ( val & 0x04 ) != 0x04 )
+            {  
+                val = read( STATUS_REG);
+                wait(0.01); //DelayMs( 10 );
+                counter++;
+                if( counter > 20 )
+                {
+                    return( 0 ); //Error out after max of 512ms for a read
+                }
+            }
+        }
+    }
+
+    msb = read( OUT_P_MSB_REG); // High byte of integer part of altitude,  
+    csb = read( OUT_P_CSB_REG); // Low byte of integer part of altitude 
+    lsb = read( OUT_P_LSB_REG); // Decimal part of altitude in bits 7-4
+    
+    decimal = ( ( float )( lsb >> 4 ) ) / 16.0;
+    //Altitude = ( float )( ( msb << 8 ) | csb ) + decimal;
+    Altitude = ( float )( ( int16_t )( ( msb << 8 ) | csb ) ) + decimal;
+
+    return( Altitude );
+}
+
+void MPL3115A2::SetModeAltimeter( void )
+{
+    uint8_t val;
+
+    SetModeStandby( );
+
+    val = read( CTRL_REG1);
+    val |= 0x80;                //Set ALT bit
+    write( CTRL_REG1, val );
+
+    SetModeActive( );
+}
+
+void MPL3115A2::ToggleOneShot( void )
+{
+    uint8_t val;
+
+    SetModeStandby( );
+
+    val = read( CTRL_REG1);
+    val &= ~(0x02);         //Clear OST bit
+    write( CTRL_REG1, val );
+
+    val = read( CTRL_REG1);
+    val |= 0x02;            //Set OST bit
+    write( CTRL_REG1, val );
+
+    SetModeActive( );
+}
+
+float MPL3115A2::ReadTemperature( void )
+{
+    uint8_t counter = 0;
+    bool negSign = false;
+    uint8_t val = 0;
+    uint8_t msb = 0, lsb = 0;
+
+    /*if( MPL3115Initialized == false )
+    {
+        return 0;
+    }*/
+
+    ToggleOneShot( );
+
+    while( ( val & 0x02 ) != 0x02 )
+    {    
+        val = read( STATUS_REG);
+        wait(0.01);
+        counter++;
+    
+        if( counter > 20 )
+        { 
+            //MPL3115Initialized = false;
+            init( );
+            ToggleOneShot( );
+            counter = 0;
+            while( ( val & 0x02 ) != 0x02 )
+            {
+                val = read( STATUS_REG);
+                wait(0.01);
+                counter++;
+            
+                if( counter > 20 )
+                { 
+                    return( 0 ); //Error out after max of 512ms for a read
+                }
+            }
+                
+        }
+    }
+
+    msb = read( OUT_T_MSB_REG); // Integer part of temperature 
+    lsb = read( OUT_T_LSB_REG); // Decimal part of temperature in bits 7-4
+
+    if( msb > 0x7F )
+    {
+        val = ~( ( msb << 8 ) + lsb ) + 1;  //2?s complement
+        msb = val >> 8;
+        lsb = val & 0x00F0; 
+        negSign = true;
+    }
+
+    if( negSign == true )
+    {
+        Temperature = 0 - ( msb + ( float )( ( lsb >> 4 ) / 16.0 ) );
+    }
+    else
+    {
+        Temperature = msb + ( float )( ( lsb >> 4 ) / 16.0 );
+    }
+
+    ToggleOneShot( );
+
+    return( Temperature );
+}
+
+