/** ****************************************************************************** * @addtogroup PIOS PIOS Core hardware abstraction layer * @{ * @addtogroup PIOS_HMC5883 HMC5883 Functions * @brief Deals with the hardware interface to the magnetometers * @{ * * @file pios_hmc5883.c * @author David "Buzz" Carlson (buzz@chebuzz.com) * The OpenPilot Team, http://www.openpilot.org Copyright (C) 2011. * @brief HMC5883 Magnetic Sensor Functions from AHRS * @see The GNU Public License (GPL) Version 3 * ****************************************************************************** */ /* * 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_HMC5883) /* Global Variables */ /* Local Types */ typedef struct { uint8_t M_ODR; /* OUTPUT DATA RATE --> here below the relative define (See datasheet page 11 for more details) */ uint8_t Meas_Conf; /* Measurement Configuration,: Normal, positive bias, or negative bias --> here below the relative define */ uint8_t Gain; /* Gain Configuration, select the full scale --> here below the relative define (See datasheet page 11 for more details) */ uint8_t Mode; } PIOS_HMC5883_ConfigTypeDef; /* Local Variables */ volatile bool pios_hmc5883_data_ready; static void PIOS_HMC5883_Config(PIOS_HMC5883_ConfigTypeDef * HMC5883_Config_Struct); static bool PIOS_HMC5883_Read(uint8_t address, uint8_t * buffer, uint8_t len); static bool PIOS_HMC5883_Write(uint8_t address, uint8_t buffer); /** * @brief Initialize the HMC5883 magnetometer sensor. * @return none */ void PIOS_HMC5883_Init(void) { GPIO_InitTypeDef GPIO_InitStructure; EXTI_InitTypeDef EXTI_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; /* Enable DRDY GPIO clock */ RCC_APB2PeriphClockCmd(PIOS_HMC5883_DRDY_CLK | RCC_APB2Periph_AFIO, ENABLE); /* Configure EOC pin as input floating */ GPIO_InitStructure.GPIO_Pin = PIOS_HMC5883_DRDY_GPIO_PIN; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_Init(PIOS_HMC5883_DRDY_GPIO_PORT, &GPIO_InitStructure); /* Configure the End Of Conversion (EOC) interrupt */ GPIO_EXTILineConfig(PIOS_HMC5883_DRDY_PORT_SOURCE, PIOS_HMC5883_DRDY_PIN_SOURCE); EXTI_InitStructure.EXTI_Line = PIOS_HMC5883_DRDY_EXTI_LINE; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); /* Enable and set EOC EXTI Interrupt to the lowest priority */ NVIC_InitStructure.NVIC_IRQChannel = PIOS_HMC5883_DRDY_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_HMC5883_DRDY_PRIO; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); /* Configure the HMC5883 Sensor */ PIOS_HMC5883_ConfigTypeDef HMC5883_InitStructure; HMC5883_InitStructure.M_ODR = PIOS_HMC5883_ODR_15; HMC5883_InitStructure.Meas_Conf = PIOS_HMC5883_MEASCONF_NORMAL; HMC5883_InitStructure.Gain = PIOS_HMC5883_GAIN_1_9; HMC5883_InitStructure.Mode = PIOS_HMC5883_MODE_CONTINUOUS; PIOS_HMC5883_Config(&HMC5883_InitStructure); pios_hmc5883_data_ready = false; } /** * @brief Initialize the HMC5883 magnetometer sensor * \return none * \param[in] PIOS_HMC5883_ConfigTypeDef struct to be used to configure 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 | 0.75 * 0 | 0 | 1 | 1.5 * 0 | 1 | 0 | 3 * 0 | 1 | 1 | 7.5 * 1 | 0 | 0 | 15 (default) * 1 | 0 | 1 | 30 * 1 | 1 | 0 | 75 * 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 | ±0.88Ga | 1370 | 0xF800–0x07FF (-2048:2047) * 0 | 0 | 1 | ±1.3Ga (def) | 1090 | 0xF800–0x07FF (-2048:2047) * 0 | 1 | 0 | ±1.9Ga | 820 | 0xF800–0x07FF (-2048:2047) * 0 | 1 | 1 | ±2.5Ga | 660 | 0xF800–0x07FF (-2048:2047) * 1 | 0 | 0 | ±4.0Ga | 440 | 0xF800–0x07FF (-2048:2047) * 1 | 0 | 1 | ±4.7Ga | 390 | 0xF800–0x07FF (-2048:2047) * 1 | 1 | 0 | ±5.6Ga | 330 | 0xF800–0x07FF (-2048:2047) * 1 | 1 | 1 | ±8.1Ga | 230 | 0xF800–0x07FF (-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 */ static void PIOS_HMC5883_Config(PIOS_HMC5883_ConfigTypeDef * HMC5883_Config_Struct) { uint8_t CTRLA = 0x00; uint8_t CTRLB = 0x00; uint8_t MODE = 0x00; CTRLA |= (uint8_t) (HMC5883_Config_Struct->M_ODR | HMC5883_Config_Struct->Meas_Conf); CTRLB |= (uint8_t) (HMC5883_Config_Struct->Gain); MODE |= (uint8_t) (HMC5883_Config_Struct->Mode); // CRTL_REGA while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A, CTRLA)) ; // CRTL_REGB while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B, CTRLB)) ; // Mode register while (!PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, MODE)) ; } /** * @brief Read current X, Z, Y values (in that order) * \param[out] int16_t array of size 3 to store X, Z, and Y magnetometer readings * \return none */ void PIOS_HMC5883_ReadMag(int16_t out[3]) { uint8_t buffer[6]; uint8_t ctrlB; pios_hmc5883_data_ready = false; while (!PIOS_HMC5883_Read(PIOS_HMC5883_CONFIG_REG_B, &ctrlB, 1)) ; while (!PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_XMSB_REG, buffer, 6)) ; switch (ctrlB & 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_HMC5883_Sensitivity_0_88Ga; 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_HMC5883_Sensitivity_1_3Ga; 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_HMC5883_Sensitivity_1_9Ga; 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_HMC5883_Sensitivity_2_5Ga; 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_HMC5883_Sensitivity_4_0Ga; 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_HMC5883_Sensitivity_4_7Ga; 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_HMC5883_Sensitivity_5_6Ga; 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_HMC5883_Sensitivity_8_1Ga; break; } } /** * @brief Read the identification bytes from the HMC5883 sensor * \param[out] uint8_t array of size 4 to store HMC5883 ID. * \return none */ void PIOS_HMC5883_ReadID(uint8_t out[4]) { while (!PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_IDA_REG, out, 3)) ; out[3] = '\0'; } /** * @brief Tells whether new magnetometer readings are available * \return true if new data is available * \return false if new data is not available */ bool PIOS_HMC5883_NewDataAvailable(void) { return (pios_hmc5883_data_ready); } /** * @brief Reads one or more bytes into a buffer * \param[in] address HMC5883 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 */ static bool PIOS_HMC5883_Read(uint8_t address, uint8_t * buffer, uint8_t len) { uint8_t addr_buffer[] = { address, }; const struct pios_i2c_txn txn_list[] = { { .info = __func__, .addr = PIOS_HMC5883_I2C_ADDR, .rw = PIOS_I2C_TXN_WRITE, .len = sizeof(addr_buffer), .buf = addr_buffer, } , { .info = __func__, .addr = PIOS_HMC5883_I2C_ADDR, .rw = PIOS_I2C_TXN_READ, .len = len, .buf = buffer, } }; return PIOS_I2C_Transfer(PIOS_I2C_MAIN_ADAPTER, txn_list, NELEMENTS(txn_list)); } /** * @brief Writes one or more bytes to the HMC5883 * \param[in] address Register address * \param[in] buffer source buffer * \return 0 if operation was successful * \return -1 if error during I2C transfer */ static bool PIOS_HMC5883_Write(uint8_t address, uint8_t buffer) { uint8_t data[] = { address, buffer, }; const struct pios_i2c_txn txn_list[] = { { .info = __func__, .addr = PIOS_HMC5883_I2C_ADDR, .rw = PIOS_I2C_TXN_WRITE, .len = sizeof(data), .buf = data, } , }; return PIOS_I2C_Transfer(PIOS_I2C_MAIN_ADAPTER, txn_list, NELEMENTS(txn_list)); } /** * @brief Run self-test operation. Do not call this during operational use!! * \return 0 if test failed * \return non-zero value if test succeeded */ int32_t PIOS_HMC5883_Test(void) { /* Verify that ID matches (HMC5883 ID is null-terminated ASCII string "H43") */ char id[4]; PIOS_HMC5883_ReadID((uint8_t *)id); if(!strncmp("H43\0",id,4)) return 0; else return 1; int32_t passed = 1; uint8_t registers[3] = {0,0,0}; /* Backup existing configuration */ while (!PIOS_HMC5883_Read(PIOS_HMC5883_CONFIG_REG_A,registers,3) ); /* * Put HMC5883 into self test mode * This is done by placing measurement config into positive (0x01) or negative (0x10) bias * and then placing the mode register into single-measurement mode. This causes the HMC5883 * to create an artificial magnetic field of ~1.1 Gauss. * * If gain were PIOS_HMC5883_GAIN_2_5, for example, X and Y will read around +766 LSB * (1.16 Ga * 660 LSB/Ga) and Z would read around +713 LSB (1.08 Ga * 660 LSB/Ga) * * Changing measurement config back to PIOS_HMC5883_MEASCONF_NORMAL will leave self-test mode. */ while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A, PIOS_HMC5883_MEASCONF_BIAS_POS | PIOS_HMC5883_ODR_15)) ; while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B, PIOS_HMC5883_GAIN_2_5)) ; while (!PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, PIOS_HMC5883_MODE_SINGLE)) ; uint8_t values[6]; while (!PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_XMSB_REG, values, 6)) ; int16_t x = (int16_t) (((uint16_t) values[0] << 8) + values[1]); int16_t y = (int16_t) (((uint16_t) values[2] << 8) + values[3]); int16_t z = (int16_t) (((uint16_t) values[4] << 8) + values[5]); if(abs(abs(x) - 766) > 20) passed &= 0; if(abs(abs(y) - 766) > 20) passed &= 0; if(abs(abs(z) - 713) > 20) passed &= 0; /* Restore backup configuration */ while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A,registers[0]) ); while (!PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B,registers[1]) ); while (!PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG,registers[2]) ); return passed; } /** * @brief IRQ Handler */ void PIOS_HMC5883_IRQHandler(void) { pios_hmc5883_data_ready = true; } #endif /* PIOS_INCLUDE_HMC5883 */ /** * @} * @} */