170bdd104f
Large change that removes the duplicated MIT notice withe a spdx tag Signed-off-by: Thomas Ingleby <thomas.ingleby@intel.com>
136 lines
3.2 KiB
C++
136 lines
3.2 KiB
C++
/*
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* Author: Brendan Le Foll <brendan.le.foll@intel.com>
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* Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
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* Copyright (c) 2014 Intel Corporation.
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*
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* SPDX-License-Identifier: MIT
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*
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* Example usage: Outputs X,Y,Z co-ordinates and direction recursively using
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* HMC5883L. Press Ctrl+C to exit.
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*
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*/
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/* standard headers */
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#include <iostream>
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#include <math.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <unistd.h>
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/* mraa headers */
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#include "mraa/common.hpp"
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#include "mraa/i2c.hpp"
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#define MAX_BUFFER_LENGTH 6
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#define HMC5883L_I2C_ADDR 0x1E
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// configuration registers
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#define HMC5883L_CONF_REG_A 0x00
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#define HMC5883L_CONF_REG_B 0x01
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// mode register
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#define HMC5883L_MODE_REG 0x02
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// data register
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#define HMC5883L_X_MSB_REG 0
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#define HMC5883L_X_LSB_REG 1
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#define HMC5883L_Z_MSB_REG 2
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#define HMC5883L_Z_LSB_REG 3
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#define HMC5883L_Y_MSB_REG 4
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#define HMC5883L_Y_LSB_REG 5
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#define DATA_REG_SIZE 6
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// status register
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#define HMC5883L_STATUS_REG 0x09
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// ID registers
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#define HMC5883L_ID_A_REG 0x0A
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#define HMC5883L_ID_B_REG 0x0B
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#define HMC5883L_ID_C_REG 0x0C
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#define HMC5883L_CONT_MODE 0x00
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#define HMC5883L_DATA_REG 0x03
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// scales
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#define GA_0_88_REG 0x00 << 5
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#define GA_1_3_REG 0x01 << 5
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#define GA_1_9_REG 0x02 << 5
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#define GA_2_5_REG 0x03 << 5
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#define GA_4_0_REG 0x04 << 5
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#define GA_4_7_REG 0x05 << 5
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#define GA_5_6_REG 0x06 << 5
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#define GA_8_1_REG 0x07 << 5
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// digital resolutions
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#define SCALE_0_73_MG 0.73
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#define SCALE_0_92_MG 0.92
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#define SCALE_1_22_MG 1.22
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#define SCALE_1_52_MG 1.52
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#define SCALE_2_27_MG 2.27
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#define SCALE_2_56_MG 2.56
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#define SCALE_3_03_MG 3.03
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#define SCALE_4_35_MG 4.35
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#define I2C_BUS 0
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volatile sig_atomic_t flag = 1;
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void
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sig_handler(int signum)
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{
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if (signum == SIGINT) {
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std::cout << "Exiting..." << std::endl;
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flag = 0;
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}
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}
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int
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main(void)
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{
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float direction;
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int16_t x, y, z;
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uint8_t rx_tx_buf[MAX_BUFFER_LENGTH];
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signal(SIGINT, sig_handler);
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//! [Interesting]
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mraa::I2c i2c(I2C_BUS);
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i2c.address(HMC5883L_I2C_ADDR);
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rx_tx_buf[0] = HMC5883L_CONF_REG_B;
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rx_tx_buf[1] = GA_1_3_REG;
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i2c.write(rx_tx_buf, 2);
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i2c.address(HMC5883L_I2C_ADDR);
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rx_tx_buf[0] = HMC5883L_MODE_REG;
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rx_tx_buf[1] = HMC5883L_CONT_MODE;
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while (flag) {
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i2c.address(HMC5883L_I2C_ADDR);
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i2c.writeByte(HMC5883L_DATA_REG);
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i2c.address(HMC5883L_I2C_ADDR);
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i2c.read(rx_tx_buf, DATA_REG_SIZE);
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x = (rx_tx_buf[HMC5883L_X_MSB_REG] << 8) | rx_tx_buf[HMC5883L_X_LSB_REG];
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z = (rx_tx_buf[HMC5883L_Z_MSB_REG] << 8) | rx_tx_buf[HMC5883L_Z_LSB_REG];
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y = (rx_tx_buf[HMC5883L_Y_MSB_REG] << 8) | rx_tx_buf[HMC5883L_Y_LSB_REG];
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// scale and calculate direction
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direction = atan2(y * SCALE_0_92_MG, x * SCALE_0_92_MG);
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// check if the signs are reversed
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if (direction < 0)
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direction += 2 * M_PI;
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std::cout << "Compass scaled data x : %f, y : %f, z : %f" << x * SCALE_0_92_MG
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<< y * SCALE_0_92_MG << z * SCALE_0_92_MG << std::endl;
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std::cout << "Heading : %f" << direction * 180 / M_PI << std::endl;
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sleep(1);
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}
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//! [Interesting]
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return EXIT_SUCCESS;
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}
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