Fork of FXOS8700CQ, with modifications to setup and some additions to class on the way to make it more application configurable... also re-did 14 bit accelerometer data transform.
Dependents: fxos8700cq_JH_explore
Fork of FXOS8700CQ by
FXOS8700CQ.cpp
- Committer:
- julianhigginson
- Date:
- 2016-02-05
- Revision:
- 7:e2b87c7f6c8d
- Parent:
- 6:f79ab691a47b
File content as of revision 7:e2b87c7f6c8d:
#include "FXOS8700CQ.h" uint8_t status_reg; // Status register contents uint8_t raw[FXOS8700CQ_READ_LEN]; // Buffer for reading out stored data // Construct class and its contents FXOS8700CQ::FXOS8700CQ(PinName sda, PinName scl, int addr) : dev_i2c(sda, scl), dev_addr(addr) { // Initialization of the I2C interface dev_i2c.frequency(I2C_400K); // Use maximum I2C frequency // Initialization of the IC write_setup(); } // Destruct class FXOS8700CQ::~FXOS8700CQ(void) {} void FXOS8700CQ::enable(void) { uint8_t data[2]; read_regs( FXOS8700CQ_CTRL_REG1, &data[1], 1); data[1] |= FXOS8700CQ_CTRL_REG1_ACTIVE; data[0] = FXOS8700CQ_CTRL_REG1; write_regs(data, 2); // write back enabled = true; } void FXOS8700CQ::disable(void) { uint8_t data[2]; read_regs( FXOS8700CQ_CTRL_REG1, &data[1], 1); data[0] = FXOS8700CQ_CTRL_REG1; data[1] &= ~FXOS8700CQ_CTRL_REG1_ACTIVE; write_regs(data, 2); // write back enabled = false; } uint8_t FXOS8700CQ::status(void) { read_regs(FXOS8700CQ_STATUS, &status_reg, 1); return status_reg; } uint8_t FXOS8700CQ::get_whoami(void) { uint8_t databyte = 0x00; read_regs(FXOS8700CQ_WHOAMI, &databyte, 1); return databyte; } uint8_t FXOS8700CQ::get_data(SRAWDATA *accel_data)//, SRAWDATA *magn_data) { if(!enabled) { return 1; } read_regs(FXOS8700CQ_OUT_X_MSB, raw, FXOS8700CQ_READ_LEN); // Pull out 14-bit, 2's complement, *L*E*F*T*-justified accelerometer data // into 16 bit variables accel_data->x = (raw[0] << 8) | raw[1]; accel_data->y = (raw[2] << 8) | raw[3]; accel_data->z = (raw[4] << 8) | raw[5]; //deal with -ve representations if (accel_data->x && 0x8000) { //MSB is ONE accel_data->x = -(~(accel_data->x)+4); } if (accel_data->y && 0x8000) { //MSB is ONE accel_data->y = -(~(accel_data->y)+4); } if (accel_data->z && 0x8000) { //MSB is ONE accel_data->z = -(~(accel_data->z)+4); } // scale back down to actual 14 bit number accel_data->x = (accel_data->x)/4; accel_data->y = (accel_data->y)/4; accel_data->z = (accel_data->z)/4; return 0; } uint8_t FXOS8700CQ::get_accel_scale(void) { uint8_t data = 0x00; read_regs(FXOS8700CQ_XYZ_DATA_CFG, &data, 1); data &= FXOS8700CQ_XYZ_DATA_CFG_FS2(3); // mask with 0b11 // Choose output value based on masked data switch(data) { case FXOS8700CQ_XYZ_DATA_CFG_FS2(0): return 2; case FXOS8700CQ_XYZ_DATA_CFG_FS2(1): return 4; case FXOS8700CQ_XYZ_DATA_CFG_FS2(2): return 8; default: return 0; } } uint8_t FXOS8700CQ::read_single_reg(uint8_t RegAddr) { uint8_t data = 0x00; read_regs(RegAddr, &data, 1); return data; } uint8_t FXOS8700CQ::write_single_reg(uint8_t RegAddr, uint8_t data) { uint8_t message[2] = {RegAddr, data}; write_regs(message, 2); return 1; } uint8_t FXOS8700CQ::write_setup(void) { uint8_t data[6] = {0, 0, 0, 0, 0, 0}; // to write over I2C: device register, up to 5 bytes data // TODO: verify WHOAMI? // Place peripheral in standby for configuration, resetting CTRL_REG1 data[0] = FXOS8700CQ_CTRL_REG1; data[1] = 0x00; // this will unset CTRL_REG1:active write_regs(data, 2); // Now that the device is in standby, configure registers at will // Setup for write-though for CTRL_REG series // Keep data[0] as FXOS8700CQ_CTRL_REG1 data[1] = 0x24; //DR3 = b100 lnoise = 1 //FXOS8700CQ_CTRL_REG1_ASLP_RATE2(1) | // 0b01 gives sleep rate of 12.5Hz //FXOS8700CQ_CTRL_REG1_DR3(3); // 0x001 gives ODR of 400Hz/200Hz hybrid // FXOS8700CQ_CTRL_REG2; data[2] = 0x12; //SMODS = MODS = 2 - high resolution. nothing else on here //FXOS8700CQ_CTRL_REG2_SMODS2(3) | // 0b11 gives low power sleep oversampling mode //FXOS8700CQ_CTRL_REG2_MODS2(1); // 0b01 gives low noise, low power oversampling mode // No configuration changes from default 0x00 in CTRL_REG3 // Interrupts will be active low, their outputs in push-pull mode data[3] = 0x00; // FXOS8700CQ_CTRL_REG4; data[4] = FXOS8700CQ_CTRL_REG4_INT_EN_DRDY; // Enable the Data-Ready interrupt // No configuration changes from default 0x00 in CTRL_REG5 // Data-Ready interrupt will appear on INT2 data[5] = 0x00; // Write to the 5 CTRL_REG registers write_regs(data, 6); // FXOS8700CQ_XYZ_DATA_CFG data[0] = FXOS8700CQ_XYZ_DATA_CFG; data[1] = FXOS8700CQ_XYZ_DATA_CFG_FS2(0); //JH 0x00 gives 2g range // 0x01 gives 4g full range, 0.488mg/LSB write_regs(data, 2); // Setup for write-through for M_CTRL_REG series data[0] = FXOS8700CQ_M_CTRL_REG1; data[1] = 0x00; //FXOS8700CQ_M_CTRL_REG1_M_ACAL | // set automatic calibration //FXOS8700CQ_M_CTRL_REG1_MO_OS3(7) | // use maximum magnetic oversampling ///FXOS8700CQ_M_CTRL_REG1_M_HMS2(3); // enable hybrid sampling (both sensors) // FXOS8700CQ_M_CTRL_REG2 data[2] = 0x00; //FXOS8700CQ_M_CTRL_REG2_HYB_AUTOINC_MODE; // FXOS8700CQ_M_CTRL_REG3 data[3] = 0x00; //FXOS8700CQ_M_CTRL_REG3_M_ASLP_OS3(7); // maximum sleep magnetic oversampling // Write to the 3 M_CTRL_REG registers //write_regs(data, 4); // Peripheral is configured, but disabled enabled = false; return 1; } // Private methods // Excepting the call to dev_i2c.frequency() in the constructor, // the use of the mbed I2C class is restricted to these methods void FXOS8700CQ::read_regs(int reg_addr, uint8_t* data, int len) { char t[1] = {reg_addr}; dev_i2c.write(dev_addr, t, 1, true); dev_i2c.read(dev_addr, (char *)data, len); } void FXOS8700CQ::write_regs(uint8_t* data, int len) { dev_i2c.write(dev_addr, (char*)data, len); }