Diff: BMA180.cpp

Revision:

0:ff755cb08068

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMA180.cpp	Wed Aug 01 20:27:16 2012 +0000
@@ -0,0 +1,153 @@
+#include "mbed.h"
+#include "BMA180.h"
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+BMA180::BMA180(PinName sdi, PinName sdo, PinName sck, PinName csb, PinName interrupt) : _csb(csb), _interrupt(interrupt), spi(sdi, sdo, sck){
+             // mosi, miso, sclk
+    _csb = 1;
+    _interrupt = 0;
+}
+
+int BMA180::validate(char id, char ver) {
+    char readID;
+    int value = 0;
+    
+    readID = readReg(id);
+    
+    if(readID == 3) {
+        value = 1;
+    } else {
+        pc.printf("Lost Connection");
+        value = -1;
+    }
+    return value;
+}
+
+void BMA180::initBMA180(void) {
+    char readVersion, readID;
+    char byte; 
+    
+    readID = readReg(CHIPID);
+    readVersion = readReg(VERSION);
+    
+    if(readID == 3) {
+        pc.printf("Connected to BMA180\n\r");
+        pc.printf("BMA180 Version: %d\n\r", readVersion);
+        
+        reset();                                           
+    
+        byte = readReg(CTRL_REG0);     
+        byte |= 0x10;                                           // Set bit4 to 1 to enable self test and unlock image writing
+        writeReg(CTRL_REG0, byte);    
+    
+        byte = readReg(DIS_I2C);                               // Read register
+        //pc.printf("\n\rDisable I2C Before: %0.3X ", byte);
+        byte |= 0x01;                                          // Set bit0 to 1 for only SPI
+        writeReg(DIS_I2C, byte);                               // Set SPI and disable I2C as per pg 31 of datasheet
+        byte = readReg(RANGE);
+        //pc.printf("After: %0.3X", byte);
+    
+        byte = readReg(RANGE);                                 // Read register
+        //pc.printf("\n\rRange Before: %0.3X ", byte);
+        byte &= 0xFB;                                          // Set bit3,2,1 to 010 for 2g
+        byte |= 0x02;
+        writeReg(RANGE, byte);
+        byte = readReg(RANGE);
+        //pc.printf("After: %0.3X", byte);
+    
+        byte = readReg(CTRL_REG3);
+        //pc.printf("\n\rRegister 3 Before: %0.3X ", byte);
+        byte |= 0x02;                                           // Set bit1 to 1 to enable new data interrupts
+        byte |= 0x40;                                           // Set bit6 to 1 to enable slope mode
+        byte |= 0x80;                                           // Set bit6 to 1 to enable slope alert
+        writeReg(CTRL_REG3, byte);
+        //pc.printf("After: %0.3X", byte);
+        pc.printf("Interrupt is enabled.");
+    
+        byte = readReg(CTRL_REG0);
+        byte &= 0xEF;                                           // Set bit4 to 0 to disable self test and lock image writing
+        writeReg(CTRL_REG0, byte);
+        
+        pc.printf("\n\rBMA initialization complete.\n\r");
+        
+    } else {
+        pc.printf("Not connected to BMA180! ReadVersion:  %d ReadID:  %d\n\r", readVersion, readID);
+    }      
+}
+
+void BMA180::reset(void) {
+    writeReg(RESET, 0xB6);
+    wait_ms(10);
+    pc.printf("Soft Reset, EEPROM Copied\n\r");
+}
+
+void BMA180::readAxis(void) {
+    int x_msb, y_msb, z_msb;
+    char x_lsb, y_lsb, z_lsb;
+    short ax, ay, az;
+    float afx, afy, afz;
+    
+    x_lsb = readReg(ACCXLSB);                              // Read X LSB register
+    x_msb = readReg(ACCXMSB);                              // Read X MSB register
+    ax = (x_msb << 8) | x_lsb;                             // Concatinate X MSB and LSB
+    ax = ax >> 2;                                          // Remove unused first 2 LSB (16 bits to 14 bits)
+    afx = (float)ax*3/16384;                               
+    
+    y_lsb = readReg(ACCYLSB);                              // Read Y LSB register
+    y_msb = readReg(ACCYMSB);                              // Read Y MSB register
+    ay = (y_msb << 8) | y_lsb;                             // Concatinate Y MSB and LSB
+    ay = ay >> 2;                                          // Remove unused first 2 LSB
+    afy = (float)ay*3/16384;
+                                
+    z_lsb = readReg(ACCZLSB);                              // Read Z LSB register
+    z_msb = readReg(ACCZMSB);                              // Read Z MSB register
+    az = (z_msb << 8) | z_lsb;                             // Concatinate Z MSB and LSB
+    az = az >> 2;                                          // Remove unused first 2 LSB
+    afz = (float)az*3/16384;
+                             
+    
+    pc.printf("\n\rX: %05f Y: %05f Z: %05f", afx, afy, afz);
+}
+
+void BMA180::writeReg(uint8_t address, char data) {
+    address &= 0x7F;                                        // Set bit7 to 0 for write mode
+    _csb = 0;                                               // Select the device
+    wait_us(2);
+    spi.write(address);                                     // Send to data register location
+    wait_us(2);
+    spi.write(data);                                        // Send value to register
+    wait_us(2);
+    _csb = 1;                                               // Deselect the device
+}
+
+char BMA180::readReg(uint8_t address) {
+    char byte;
+
+    address |= 0x80;                                        // Set bit7 to 1 for read mode
+    _csb = 0;                                               // Select the device
+    wait_us(2);
+    spi.write(address);                                     // Send to data register location
+    wait_us(2);
+    byte = spi.write(address);                              // Get data
+    wait_us(2);
+    _csb = 1;                                               // Deselect the device
+    wait_us(2);
+    return byte;
+}
+
+void BMA180::disInt(void) {
+    char byte;
+    
+    byte = readReg(CTRL_REG0);     
+    byte |= 0x10;                                           // Set bit4 to 1 to enable self test and unlock image writing
+    writeReg(CTRL_REG0, byte);
+    
+    byte = readReg(CTRL_REG3);                              // Unlock image writing
+    byte &= 0xFD;                                           // Set bit1 to 0 to disable interrupt
+    writeReg(CTRL_REG3, byte);
+        
+    byte = readReg(CTRL_REG0);
+    byte &= 0xEF;                                           // Set bit4 to 0 to disable self test and lock image writing
+    writeReg(CTRL_REG0, byte);
+}