A mbed-os v5 driver for BM1422AGMV (3 axis magnetic sensor, made by Rohm).
Dependents: rohm-SensorShield-example mbed_blinky
Diff: BM1422AGMV.cpp
- Revision:
- 0:203311da9813
diff -r 000000000000 -r 203311da9813 BM1422AGMV.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BM1422AGMV.cpp Mon Feb 18 13:00:55 2019 +0900 @@ -0,0 +1,143 @@ +/* Copyright (c) 2015 ARM Ltd., MIT License +* +* Permission is hereby granted, free of charge, to any person obtaining a copy of this software +* and associated documentation files (the "Software"), to deal in the Software without +* restriction, including without limitation the rights to use, copy, modify, merge, publish, +* distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the +* Software is furnished to do so, subject to the following conditions: +* +* The above copyright notice and this permission notice shall be included in all copies or +* substantial portions of the Software. +* +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING +* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, +* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +* +*/ + +#include "mbed.h" +#include "BM1422AGMV.h" + +BM1422AGMV::BM1422AGMV(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) +{ + initialize(); +} + +BM1422AGMV::BM1422AGMV(I2C &i2c_obj, int addr) : m_i2c(i2c_obj), m_addr(addr) +{ + initialize(); +} + +BM1422AGMV::~BM1422AGMV() +{ + /* do nothing */ +} + +void BM1422AGMV::initialize(void) +{ + uint8_t reg; + uint8_t buf[3]; + + DEBUG_PRINT("BM1422AGMV init started\n\r"); + + readRegs(BM1422AGMV_WIA, ®, 1); + + if ( reg != BM1422AGMV_WIA_VAL) { + DEBUG_PRINT("BM1422AGMV initialization error. (WAI %d, not %d)\n\r", buf, BM1422AGMV_WIA); + DEBUG_PRINT("Trying to config anyway, in case there is some compatible sensor connected.\n\r"); + } + + // Step1 + buf[0] = BM1422AGMV_CNTL1; + buf[1] = BM1422AGMV_CNTL1_VAL; + writeRegs(buf, 2); + + // Check 12bit or 14bit + reg = (BM1422AGMV_CNTL1_VAL & BM1422AGMV_CNTL1_OUT_BIT); + if (reg == BM1422AGMV_CNTL1_OUT_BIT) { + _sens = BM1422AGMV_14BIT_SENS; + } else { + _sens = BM1422AGMV_12BIT_SENS; + } + + wait(1); + + buf[0] = BM1422AGMV_CNTL4; + buf[1] = (BM1422AGMV_CNTL4_VAL >> 8) & 0xFF; + buf[2] = (BM1422AGMV_CNTL4_VAL & 0xFF); + writeRegs(buf, 3); + + // Step2 + buf[0] = BM1422AGMV_CNTL2; + buf[1] = BM1422AGMV_CNTL2_VAL; + writeRegs(buf, 2); + + // Step3 + + // Option + buf[0] = BM1422AGMV_AVE_A; + buf[1] = BM1422AGMV_AVE_A_VAL; + writeRegs(buf, 2); +} + +void BM1422AGMV::get_rawval(unsigned char *data) +{ + uint8_t reg; + uint8_t buf[2]; + + // Step 4 + buf[0] = BM1422AGMV_CNTL3; + buf[1] = BM1422AGMV_CNTL3_VAL; + writeRegs(buf, 2); + + while(1) { + readRegs(BM1422AGMV_STA1, ®, 1); + if ( (reg>>6) == 1) { + break; + } + wait_ms(100); + } + + readRegs(BM1422AGMV_DATAX, data, 6); +} + +void BM1422AGMV::get_val(float *data) +{ + uint8_t val[6]; + int16_t mag[3]; + + get_rawval(val); + + mag[0] = ((int16_t)val[1] << 8) | (int16_t)(val[0]); + mag[1] = ((int16_t)val[3] << 8) | (int16_t)(val[2]); + mag[2] = ((int16_t)val[5] << 8) | (int16_t)(val[4]); + + convert_uT(mag, data); +} + +void BM1422AGMV::convert_uT(int16_t *rawdata, float *data) +{ + // LSB to uT + data[0] = (float)rawdata[0] / _sens; + data[1] = (float)rawdata[1] / _sens; + data[2] = (float)rawdata[2] / _sens; +} + +void BM1422AGMV::readRegs(int addr, uint8_t * data, int len) +{ + int read_nok; + char t[1] = {addr}; + + m_i2c.write(m_addr, t, 1, true); + read_nok = m_i2c.read(m_addr, (char *)data, len); + if (read_nok){ + DEBUG_PRINT("Read fail\n\r"); + } +} + +void BM1422AGMV::writeRegs(uint8_t * data, int len) +{ + m_i2c.write(m_addr, (char *)data, len); +}