1
0
mirror of https://bitbucket.org/librepilot/librepilot.git synced 2024-12-05 13:24:11 +01:00
LibrePilot/flight/PiOS/Common/pios_hmc5843.c

242 lines
7.9 KiB
C
Raw Normal View History

/**
******************************************************************************
*
* @file pios_hmc5843.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief HMC5843 Magnetic Sensor Functions
* @see The GNU Public License (GPL) Version 3
* @defgroup PIOS_HMC5843 HMC5843 Functions
* @{
*
*****************************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Project Includes */
#include "pios.h"
#if defined(PIOS_INCLUDE_HMC5843)
/* Glocal Variables */
/* Local Variables */
/**
* Initialise the HMC5843 sensor
*/
void PIOS_HMC5843_Init(void)
{
// Nothing to do here
// If we were using the DRDY (data ready) interrupt input, we would set it up here
}
/**
* Initialise the HMC5843 sensor
*
* CTRL_REGA: Control Register A
* Read Write
* Default value: 0x10
* 7:5 0 These bits must be cleared for correct operation.
* 4:2 DO2-DO0: Data Output Rate Bits
* DO2 | DO1 | DO0 | Minimum Data Output Rate (Hz)
* ------------------------------------------------------
* 0 | 0 | 0 | 0.5
* 0 | 0 | 1 | 1
* 0 | 1 | 0 | 2
* 0 | 1 | 1 | 5
* 1 | 0 | 0 | 10 (default)
* 1 | 0 | 1 | 20
* 1 | 1 | 0 | 50
* 1 | 1 | 1 | Not Used
* 1:0 MS1-MS0: Measurement Configuration Bits
* MS1 | MS0 | MODE
* ------------------------------
* 0 | 0 | Normal
* 0 | 1 | Positive Bias
* 1 | 0 | Negative Bias
* 1 | 1 | Not Used
*
* CTRL_REGB: Control RegisterB
* Read Write
* Default value: 0x20
* 7:5 GN2-GN0: Gain Configuration Bits.
* GN2 | GN1 | GN0 | Mag Input | Gain | Output Range
* | | | Range[Ga] | [LSB/mGa] |
* ------------------------------------------------------
* 0 | 0 | 0 | <EFBFBD>0.7Ga | 1620 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 0 | 0 | 1 | <EFBFBD>1.0Ga (def) | 1300 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 0 | 1 | 0 | <EFBFBD>1.5Ga | 970 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 0 | 1 | 1 | <EFBFBD>2.0Ga | 780 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 1 | 0 | 0 | <EFBFBD>3.2Ga | 530 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 1 | 0 | 1 | <EFBFBD>3.8Ga | 460 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 1 | 1 | 0 | <EFBFBD>4.5Ga | 390 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* 1 | 1 | 1 | <EFBFBD>6.5Ga | 280 | 0xF800<EFBFBD>0x07FF (-2048:2047)
* |Not recommended|
*
* 4:0 CRB4-CRB: 0 This bit must be cleared for correct operation.
*
* _MODE_REG: Mode Register
* Read Write
* Default value: 0x02
* 7:2 0 These bits must be cleared for correct operation.
* 1:0 MD1-MD0: Mode Select Bits
* MS1 | MS0 | MODE
* ------------------------------
* 0 | 0 | Continuous-Conversion Mode.
* 0 | 1 | Single-Conversion Mode
* 1 | 0 | Negative Bias
* 1 | 1 | Sleep Mode
*/
void PIOS_HMC5843_Config(PIOS_HMC5843_ConfigTypeDef *HMC5843_Config_Struct)
{
uint8_t CRTLA = 0x00;
uint8_t CRTLB = 0x00;
uint8_t MODE = 0x00;
CRTLA |= (uint8_t) (HMC5843_Config_Struct->M_ODR | HMC5843_Config_Struct->Meas_Conf);
CRTLB |= (uint8_t) (HMC5843_Config_Struct->Gain);
MODE |= (uint8_t) (HMC5843_Config_Struct->Mode);
// CRTL_REGA
PIOS_HMC5843_Write(PIOS_HMC5843_CONFIG_REG_A, CRTLA);
// CRTL_REGB
PIOS_HMC5843_Write(PIOS_HMC5843_CONFIG_REG_B, CRTLB);
// Mode register
PIOS_HMC5843_Write(PIOS_HMC5843_MODE_REG, MODE);
}
/**
* Read the magnetic readings from the sensor
*/
void PIOS_HMC5843_ReadMag(int16_t *out)
{
uint8_t buffer[6];
uint8_t crtlB;
PIOS_HMC5843_Read(PIOS_HMC5843_CONFIG_REG_B, &crtlB, 1);
PIOS_HMC5843_Read(PIOS_HMC5843_DATAOUT_XMSB_REG, buffer, 6);
switch(crtlB & 0xE0) {
case 0x00:
for(int i = 0; i < 3; i++)
out[i] = ((int16_t) ((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_0_7Ga;
break;
case 0x20:
for(int i = 0; i < 3; i++)
out[i] = ((int16_t) ((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_1Ga;
break;
case 0x40:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_1_5Ga;
break;
case 0x60:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_2Ga;
break;
case 0x80:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_3_2Ga;
break;
case 0xA0:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_3_8Ga;
break;
case 0xC0:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_4_5Ga;
break;
case 0xE0:
for(int i = 0; i < 3; i++)
out[i] = (int16_t) (((uint16_t) buffer[2 * i] << 8)
+ buffer[2 * i + 1]) * 1000
/ PIOS_HMC5843_Sensitivity_6_5Ga;
break;
}
}
/**
* Read the identification bytes from the sensor
*/
void PIOS_HMC5843_ReadID(uint8_t *out)
{
PIOS_HMC5843_Read(PIOS_HMC5843_DATAOUT_IDA_REG, out, 3);
}
/**
* Reads one or more bytes into a buffer
* \param[in] address HMC5843 register address (depends on size)
* \param[out] buffer destination buffer
* \param[in] len number of bytes which should be read
* \return 0 if operation was successful
* \return -1 if error during I2C transfer
* \return -4 if invalid length
*/
int32_t PIOS_HMC5843_Read(uint8_t address, uint8_t *buffer, uint8_t len)
{
/* Send I2C address and register address */
/* To avoid issues copy address into temporary buffer */
uint8_t addr_buffer[1] = {(uint8_t)address};
int32_t error = PIOS_I2C_Transfer(I2C_Write_WithoutStop, PIOS_HMC5843_I2C_ADDR, addr_buffer, 1);
/* Now receive byte(s) */
if(!error) {
error = PIOS_I2C_Transfer(I2C_Read, PIOS_HMC5843_I2C_ADDR, buffer, len);
}
/* Return error status */
return error < 0 ? -1 : 0;
}
/**
* Writes one or more bytes to the HMC5843
* \param[in] address Register address
* \param[in] buffer source buffer
* \return 0 if operation was successful
* \return -1 if error during I2C transfer
*/
int32_t PIOS_HMC5843_Write(uint8_t address, uint8_t buffer)
{
/* Send I2C address and data */
uint8_t WriteBuffer[2];
WriteBuffer[0] = address;
WriteBuffer[1] = buffer;
int32_t error = PIOS_I2C_Transfer(I2C_Write, PIOS_HMC5843_I2C_ADDR, WriteBuffer, 2);
/* Return error status */
return error < 0 ? -1 : 0;
}
#endif