Accelerometer test
Fork of BMA180 by
Diff: BMA180.cpp
- Revision:
- 0:ff755cb08068
- Child:
- 1:76ba09761dbe
--- /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); +}