Diff: HMC5883L.cpp

Revision:

0:a1ad0eb8b619

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HMC5883L.cpp	Mon Apr 16 07:16:00 2018 +0000
@@ -0,0 +1,133 @@
+#include "HMC5883L.h"
+
+HMC5883L::HMC5883L(PinName sda, PinName scl): i2c(sda, scl)
+{
+    //100KHz, as specified by the datasheet.
+    char rx;
+
+    
+    i2c.frequency(400000);
+    //Testar depois com 400KHz
+    //==========================================================================================================
+    // Read chip_id
+    //==========================================================================================================
+    rx = Read(HMC5883L_IDENT_A);
+    if (rx != 0x48)//ID do chip
+        printf("\ninvalid chip id %d\r\n", rx); 
+     
+    //==========================================================================================================
+    // Let's set the Configuration Register A
+    //==========================================================================================================
+    // This register set's the number of samples averaged per measurement output, the rate at which data is written
+    // to all three data output registers and the measurement flow of the device.
+    // -------------------------------------------------------
+    // |CRA7 CRA6   CRA5   CRA4   CRA3   CRA2   CRA1   CRA0  |
+    // |(1)  MA1(1) MA0(1) DO2(1) DO1(0) DO0(0) MS1(0) MS0(0)| -> This is the default value
+    // -------------------------------------------------------
+    // CRA7 -> we have to clear this bit for correct operation                                      (0)
+    // CRA6 to CRA5 -> Let's select the maximum number of samples averaged per measurement output   (11)
+    // CRA4 to CRA2 -> Also let's select the maximum data output rate                               (110)
+    // CRA1 to CRA0 -> The measurement flow is defined to normal                                    (00)
+    // -------------------------------------------------------
+    // |CRA7 CRA6   CRA5   CRA4   CRA3   CRA2   CRA1   CRA0  |
+    // |(0)  MA1(1) MA0(1) DO2(1) DO1(1) DO0(0) MS1(0) MS0(0)| -> This is the new value, 0x78 in hex
+    // -------------------------------------------------------
+    //Write(HMC5883L_CONFIG_A,0x78);
+    //Write(HMC5883L_CONFIG_A,0x70);
+        
+    //==========================================================================================================
+    // The Configuration Register B is set to 0010 0000 by default, this is a +/- 1.3 Ga sensor field range and
+    // the gain of LSB/gauss is 1090. This is the maximum value, so let's leave it like that.
+    //==========================================================================================================
+    //Datasheet page 13. I will explain later
+    //Write(HMC5883L_CONFIG_B,0x20);
+    //Write(HMC5883L_CONFIG_B,0xA0);
+  
+    //==========================================================================================================
+    // Let's set the Mode Register
+    //==========================================================================================================
+    // This register set's the operation mode, from continuous-measurements mode, single-measurement mode and idle mode.
+    // We will set to Continuouse-measurement mode, so the device continuously performs measurements and places the
+    // result in the data register
+    // ---------------------------------------------
+    // |MR7  MR6  MR5  MR4  MR3  MR2  MR1    MR0   |  -> This is the new value, 0x78 in hex, we are going to change
+    // |(1)  (0)  (0)  (0)  (0)  (0)  MD1(0) MD0(1)|     the MD1 and MD0 to 00 and clear the MR7 for correct operation.
+    // ---------------------------------------------     The final value is 0000 0000 (0x00).
+    Write(HMC5883L_MODE,0x00);
+}
+
+
+void HMC5883L::Write(char reg_address, char data)
+{
+    char tx[2];
+    tx[0]=reg_address;
+    tx[1]=data;
+
+    i2c.write(HMC5883L_I2C_WRITE,tx,2);
+}
+
+char HMC5883L::Read(char data)
+{
+    char tx = data;
+    char rx;
+
+    i2c.write(HMC5883L_I2C_WRITE, &tx, 1);
+    i2c.read(HMC5883L_I2C_READ, &rx, 1);
+    return rx;
+}
+
+void HMC5883L::MultiByteRead(char address, char* output, int size) 
+{
+    i2c.write(HMC5883L_I2C_WRITE, &address, 1);      //tell it where to read from
+    i2c.read(HMC5883L_I2C_READ, output, size);     //tell it where to store the data read
+}
+
+float HMC5883L::getMx()
+{
+    //return (x * m_Scale);
+    char lsb_byte = 0;
+    signed short msb_byte;
+
+    lsb_byte = Read(HMC5883L_X_MSB);
+    msb_byte = lsb_byte << 8;
+    msb_byte |= Read(HMC5883L_X_LSB);
+    return (float)msb_byte;
+    /*
+    char tx[1];
+    char rx[2];
+
+
+    tx[0]=HMC5883L_X_MSB;
+    i2c.write(HMC5883L_I2C_READ,tx,1);
+    i2c.read(HMC5883L_I2C_READ,rx,2);
+    return ((int)rx[0]<<8|(int)rx[1]);
+    */
+
+}
+
+float HMC5883L::getMy()
+{
+    //return (y * m_Scale);
+
+    char lsb_byte = 0;
+    signed short msb_byte;
+
+    lsb_byte = Read(HMC5883L_Y_MSB);
+    msb_byte = lsb_byte << 8;
+    msb_byte |= Read(HMC5883L_Y_LSB);
+    return (float)msb_byte;
+}
+
+
+float HMC5883L::getMz()
+{
+    //return (z * m_Scale);
+    
+    char lsb_byte = 0;
+    signed short msb_byte;
+
+    lsb_byte = Read(HMC5883L_Z_MSB);
+    msb_byte = lsb_byte << 8;
+    msb_byte |= Read(HMC5883L_Z_LSB);
+    return (float)msb_byte;
+ }
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