diff options
Diffstat (limited to 'nuttx/configs/px4fmu/src/drv_ms5611.c')
-rw-r--r-- | nuttx/configs/px4fmu/src/drv_ms5611.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/nuttx/configs/px4fmu/src/drv_ms5611.c b/nuttx/configs/px4fmu/src/drv_ms5611.c new file mode 100644 index 000000000..7fea65159 --- /dev/null +++ b/nuttx/configs/px4fmu/src/drv_ms5611.c @@ -0,0 +1,493 @@ +/* + * Copyright (C) 2012 Lorenz Meier. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name of the author or the names of contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * Driver for the Measurement Specialties MS5611 barometric pressure sensor + */ + +#include <nuttx/config.h> +#include <nuttx/i2c.h> +#include <nuttx/arch.h> +#include <arch/board/board.h> + +#include <stdint.h> +#include <stdbool.h> +#include <debug.h> +#include <errno.h> +#include <string.h> +#include <stdio.h> +#include <math.h> + +#include "chip.h" +#include "px4fmu-internal.h" + +#include <arch/board/up_hrt.h> +#include <arch/board/drv_ms5611.h> + +/* internal conversion time: 9.17 ms, so should not be read at rates higher than 100 Hz */ +#define MS5611_MIN_INTER_MEASUREMENT_INTERVAL 9200 + +#define MS5611_ADDRESS_1 0x76 /* address select pins pulled high (PX4FMU series v1.6+) */ +#define MS5611_ADDRESS_2 0x77 /* address select pins pulled low (PX4FMU prototypes) */ + +#define ADDR_RESET_CMD 0x1E /* read from this address to reset chip (0b0011110 on bus) */ +#define ADDR_CMD_CONVERT_D1 0x48 /* 4096 samples to this address to start conversion (0b01001000 on bus) */ +#define ADDR_CMD_CONVERT_D2 0x58 /* 4096 samples */ +#define ADDR_DATA 0x00 /* address of 3 bytes / 32bit pressure data */ +#define ADDR_PROM_SETUP 0xA0 /* address of 8x 2 bytes factory and calibration data */ +#define ADDR_PROM_C1 0xA2 /* address of 6x 2 bytes calibration data */ + +static FAR struct ms5611_dev_s ms5611_dev; + +static ssize_t ms5611_read(struct file *filp, FAR char *buffer, size_t buflen); +static int ms5611_ioctl(struct file *filp, int cmd, unsigned long arg); + +static const struct file_operations ms5611_fops = { + .read = ms5611_read, + .ioctl = ms5611_ioctl, +}; + +struct ms5611_prom_s +{ + uint16_t factory_setup; + uint16_t c1_pressure_sens; + uint16_t c2_pressure_offset; + uint16_t c3_temp_coeff_pres_sens; + uint16_t c4_temp_coeff_pres_offset; + uint16_t c5_reference_temp; + uint16_t c6_temp_coeff_temp; + uint16_t serial_and_crc; +} __attribute__((packed)); + +union ms5611_prom_u +{ + uint16_t c[8]; + struct ms5611_prom_s s; +} __attribute__((packed)); + +struct ms5611_dev_s +{ + union ms5611_prom_u prom; + struct i2c_dev_s *i2c; + struct ms5611_buffer *buffer; +} __attribute__((packed)); + +static FAR uint8_t MS5611_ADDRESS; + +static FAR struct { + /* status register and data as read back from the device */ + float pressure; + float altitude; + float temperature; + uint32_t d1_raw; + uint32_t d2_raw; + uint32_t measurements_count; + uint8_t last_state; + uint64_t last_read; + } ms5611_report = { + .pressure = 0.0f, + .altitude = 0.0f, + .temperature = 0.0f, + .last_state = 0, + /* make sure the first readout can be performed */ + .last_read = 0, +}; + +static int ms5611_read_prom(void); + +static bool +read_values(float *data) +{ + int ret; + uint8_t cmd_data[3]; + + /* check validity of pointer */ + if (data == NULL) + { + *get_errno_ptr() = EINVAL; + return -EINVAL; + } + + /* only start reading when data is available */ + if (ms5611_report.measurements_count > 0) + { + /* do not read more often than at minimum 9.17 ms intervals */ + if ((hrt_absolute_time() - ms5611_report.last_read) < MS5611_MIN_INTER_MEASUREMENT_INTERVAL) + { + /* set errno to 'come back later' */ + ret = -EAGAIN; + goto handle_return; + } + else + { + /* set new value */ + ms5611_report.last_read = hrt_absolute_time(); + } + + /* Read out last measurement */ + cmd_data[0] = 0x00; + + struct i2c_msg_s msgv[2] = { + { + .addr = MS5611_ADDRESS, + .flags = 0, + .buffer = cmd_data, + .length = 1 + }, + { + .addr = MS5611_ADDRESS, + .flags = I2C_M_READ, + .buffer = cmd_data, + .length = 3 + } + }; + ret = I2C_TRANSFER(ms5611_dev.i2c, msgv, 2); + if (ret != OK) goto handle_return; + + + /* at value 1 the last reading was temperature */ + if (ms5611_report.last_state == 1) + { + /* put temperature into the raw set */ + ms5611_report.d2_raw = (((uint32_t)cmd_data[0]) << 16) | (((uint32_t)cmd_data[1]) << 8) | ((uint32_t)cmd_data[2]); + } + else + { + /* put altitude into the raw set */ + ms5611_report.d1_raw = (((uint32_t)cmd_data[0]) << 16) | (((uint32_t)cmd_data[1]) << 8) | ((uint32_t)cmd_data[2]); + } + } + ms5611_report.measurements_count++; + + /* + * this block reads four pressure values and one temp value, + * resulting in 80 Hz pressure update and 20 Hz temperature updates + * at 100 Hz continuous operation. + */ + if (ms5611_report.last_state == 0) + { + /* request first a temperature reading */ + cmd_data[0] = ADDR_CMD_CONVERT_D2; + } + else + { + /* request pressure reading */ + cmd_data[0] = ADDR_CMD_CONVERT_D1; + } + + if (ms5611_report.last_state == 3) + { + ms5611_report.last_state = 0; + } + else + { + ms5611_report.last_state++; + } + + + /* write measurement command */ + struct i2c_msg_s conv_cmd[1] = { + { + .addr = MS5611_ADDRESS, + .flags = 0, + .buffer = cmd_data, + .length = 1 + }, + }; + + ret = I2C_TRANSFER(ms5611_dev.i2c, conv_cmd, 1); + if (ret != OK) goto handle_return; + + /* only write back values after first complete set */ + if (ms5611_report.measurements_count > 2) + { + /* Calculate results */ + + /* temperature calculation */ + int32_t dT = ms5611_report.d2_raw - (((int32_t)ms5611_dev.prom.s.c5_reference_temp)*256); + int64_t temp_int64 = 2000 + (((int64_t)dT)*ms5611_dev.prom.s.c6_temp_coeff_temp)/8388608; + + /* pressure calculation */ + int64_t offset = (int64_t)ms5611_dev.prom.s.c2_pressure_offset * 65536 + ((int64_t)dT*ms5611_dev.prom.s.c4_temp_coeff_pres_offset)/128; + int64_t sens = (int64_t)ms5611_dev.prom.s.c1_pressure_sens * 32768 + ((int64_t)dT*ms5611_dev.prom.s.c3_temp_coeff_pres_sens)/256; + + /* it's pretty cold, second order temperature compensation needed */ + if (temp_int64 < 2000) + { + /* second order temperature compensation */ + int64_t temp2 = (((int64_t)dT)*dT) >> 31; + int64_t tmp_64 = (temp_int64-2000)*(temp_int64-2000); + int64_t offset2 = (5*tmp_64)>>1; + int64_t sens2 = (5*tmp_64)>>2; + temp_int64 = temp_int64 - temp2; + offset = offset - offset2; + sens = sens - sens2; + } + + int64_t press_int64 = (((ms5611_report.d1_raw*sens)/2097152-offset)/32768); + + ms5611_report.temperature = temp_int64 / 100.0f; + ms5611_report.pressure = press_int64 / 100.0f; + /* convert as double for max. precision, store as float (more than enough precision) */ + ms5611_report.altitude = (44330.0 * (1.0 - pow((press_int64 / 101325.0), 0.190295))); + + /* Write back float values */ + data[0] = ms5611_report.pressure; + data[1] = ms5611_report.altitude; + data[2] = ms5611_report.temperature; + } + else + { + /* not ready, try again */ + ret = -EINPROGRESS; + } + + /* return 1 if new data is available, 0 else */ + handle_return: + if (ret == OK) + { + return (sizeof(ms5611_report.d1_raw) + sizeof(ms5611_report.altitude) + sizeof(ms5611_report.d2_raw)); + } + else + { + errno = -ret; + return ret; + } +} + +static ssize_t +ms5611_read(struct file *filp, char *buffer, size_t buflen) +{ + /* if the buffer is large enough, and data are available, return success */ + if (buflen >= 12) { + return read_values((float *)buffer); + } + + /* buffer too small */ + errno = ENOSPC; + return -ENOSPC; +} + +static int +ms5611_ioctl(struct file *filp, int cmd, unsigned long arg) +{ + return -ENOSYS; + +// switch (cmd) { +// case MS5611_SETRATE: +// if ((arg & REG1_RATE_LP_MASK) == arg) { +// set_rate(arg); +// result = 0; +// dev.rate = arg; +// } +// break; +// +// case MS5611_SETBUFFER: +// dev.buffer = (struct ms5611_buffer *)arg; +// result = 0; +// break; +// } +// +// if (result) +// errno = EINVAL; +// return result; +} + + + +int ms5611_crc4(uint16_t n_prom[]) +{ + /* routine ported from MS5611 application note */ + int16_t cnt; + uint16_t n_rem; + uint16_t crc_read; + uint8_t n_bit; + n_rem = 0x00; + /* save the read crc */ + crc_read = n_prom[7]; + /* remove CRC byte */ + n_prom[7] = (0xFF00 & (n_prom[7])); + for (cnt = 0; cnt < 16; cnt++) + { + /* uneven bytes */ + if (cnt & 1) + { + n_rem ^= (uint8_t) ((n_prom[cnt>>1]) & 0x00FF); + } + else + { + n_rem ^= (uint8_t) (n_prom[cnt>>1] >> 8); + } + for (n_bit = 8; n_bit > 0; n_bit--) + { + if (n_rem & 0x8000) + { + n_rem = (n_rem << 1) ^ 0x3000; + + } + else + { + n_rem = (n_rem << 1); + } + } + } + /* final 4 bit remainder is CRC value */ + n_rem = (0x000F & (n_rem >> 12)); + n_prom[7] = crc_read; + + /* return 0 == OK if CRCs match, 1 else */ + return !((0x000F & crc_read) == (n_rem ^ 0x00)); +} + + +int ms5611_read_prom() +{ + /* read PROM data */ + uint8_t prom_buf[2] = {255,255}; + + int retval = 0; + + for (int i = 0; i < 8; i++) + { + uint8_t cmd = {ADDR_PROM_SETUP + (i*2)}; + + I2C_SETADDRESS(ms5611_dev.i2c, MS5611_ADDRESS, 7); + retval = I2C_WRITEREAD(ms5611_dev.i2c, &cmd, 1, prom_buf, 2); + + /* assemble 16 bit value and convert from big endian (sensor) to little endian (MCU) */ + ms5611_dev.prom.c[i] = (((uint16_t)prom_buf[0])<<8) | ((uint16_t)prom_buf[1]); + + if (retval != OK) + { + break; + } + } + + /* calculate CRC and return error if mismatch */ + return ms5611_crc4(ms5611_dev.prom.c); +} + +int +ms5611_attach(struct i2c_dev_s *i2c) +{ + int result = ERROR; + + ms5611_dev.i2c = i2c; + + MS5611_ADDRESS = MS5611_ADDRESS_1; + + /* write reset command */ + uint8_t cmd_data = ADDR_RESET_CMD; + + struct i2c_msg_s reset_cmd[1] = { + { + .addr = MS5611_ADDRESS, + .flags = 0, + .buffer = &cmd_data, + .length = 1 + }, + }; + + int ret = I2C_TRANSFER(ms5611_dev.i2c, reset_cmd, 1); + + if (ret == OK) + { + /* wait for PROM contents to be in the device (2.8 ms) */ + up_udelay(3000); + + /* read PROM */ + ret = ms5611_read_prom(); + } + + /* check if the address was wrong */ + if (ret != OK) + { + /* try second address */ + MS5611_ADDRESS = MS5611_ADDRESS_2; + + /* write reset command */ + cmd_data = ADDR_RESET_CMD; + + struct i2c_msg_s reset_cmd_2[1] = { + { + .addr = MS5611_ADDRESS, + .flags = 0, + .buffer = &cmd_data, + .length = 1 + }, + }; + + ret = I2C_TRANSFER(ms5611_dev.i2c, reset_cmd_2, 1); + + /* wait for PROM contents to be in the device (2.8 ms) */ + up_udelay(3000); + + /* read PROM */ + ret = ms5611_read_prom(); + } + + if (ret < 0) return -EIO; + + + /* verify that the device is attached and functioning */ + if (ret == OK) { + + if (MS5611_ADDRESS == MS5611_ADDRESS_1) + { + printf("[ms5611 driver] Attached MS5611 at addr #1 (0x76)\n"); + } + else + { + printf("[ms5611 driver] Attached MS5611 at addr #2 (0x77)\n"); + } + + /* trigger temperature read */ + (void)read_values(NULL); + /* wait for conversion to complete */ + up_udelay(9200); + + /* trigger pressure read */ + (void)read_values(NULL); + /* wait for conversion to complete */ + up_udelay(9200); + /* now a read_values call would obtain valid results */ + + /* make ourselves available */ + register_driver("/dev/ms5611", &ms5611_fops, 0666, NULL); + + result = OK; + + } else { + errno = EIO; + } + + return result; +} |