atbetaflight/src/main/drivers/barometer/barometer_ms5611.c

221 lines
6.4 KiB
C

/*
* This file is part of Cleanflight.
*
* Cleanflight 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.
*
* Cleanflight 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 Cleanflight. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdbool.h>
#include <stdint.h>
#include <platform.h>
#include "build/build_config.h"
#include "barometer.h"
#include "barometer_spi_ms5611.h"
#include "drivers/bus_i2c.h"
#include "drivers/gpio.h"
#include "drivers/time.h"
// MS5611, Standard address 0x77
#define MS5611_ADDR 0x77
#define CMD_RESET 0x1E // ADC reset command
#define CMD_ADC_READ 0x00 // ADC read command
#define CMD_ADC_CONV 0x40 // ADC conversion command
#define CMD_ADC_D1 0x00 // ADC D1 conversion
#define CMD_ADC_D2 0x10 // ADC D2 conversion
#define CMD_ADC_256 0x00 // ADC OSR=256
#define CMD_ADC_512 0x02 // ADC OSR=512
#define CMD_ADC_1024 0x04 // ADC OSR=1024
#define CMD_ADC_2048 0x06 // ADC OSR=2048
#define CMD_ADC_4096 0x08 // ADC OSR=4096
#define CMD_PROM_RD 0xA0 // Prom read command
#define PROM_NB 8
static void ms5611_reset(void);
static uint16_t ms5611_prom(int8_t coef_num);
STATIC_UNIT_TESTED int8_t ms5611_crc(uint16_t *prom);
static uint32_t ms5611_read_adc(void);
static void ms5611_start_ut(void);
static void ms5611_get_ut(void);
static void ms5611_start_up(void);
static void ms5611_get_up(void);
STATIC_UNIT_TESTED void ms5611_calculate(int32_t *pressure, int32_t *temperature);
STATIC_UNIT_TESTED uint32_t ms5611_ut; // static result of temperature measurement
STATIC_UNIT_TESTED uint32_t ms5611_up; // static result of pressure measurement
STATIC_UNIT_TESTED uint16_t ms5611_c[PROM_NB]; // on-chip ROM
static uint8_t ms5611_osr = CMD_ADC_4096;
bool ms5611Detect(baroDev_t *baro)
{
uint8_t sig;
int i;
delay(10); // No idea how long the chip takes to power-up, but let's make it 10ms
#ifdef USE_BARO_SPI_MS5611
ms5611SpiInit();
ms5611SpiReadCommand(CMD_PROM_RD, 1, &sig);
if (sig == 0xFF)
return false;
#else
if (!i2cRead(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_PROM_RD, 1, &sig))
return false;
#endif
ms5611_reset();
// read all coefficients
for (i = 0; i < PROM_NB; i++)
ms5611_c[i] = ms5611_prom(i);
// check crc, bail out if wrong - we are probably talking to BMP085 w/o XCLR line!
if (ms5611_crc(ms5611_c) != 0)
return false;
// TODO prom + CRC
baro->ut_delay = 10000;
baro->up_delay = 10000;
baro->start_ut = ms5611_start_ut;
baro->get_ut = ms5611_get_ut;
baro->start_up = ms5611_start_up;
baro->get_up = ms5611_get_up;
baro->calculate = ms5611_calculate;
return true;
}
static void ms5611_reset(void)
{
#ifdef USE_BARO_SPI_MS5611
ms5611SpiWriteCommand(CMD_RESET, 1);
#else
i2cWrite(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_RESET, 1);
#endif
delayMicroseconds(2800);
}
static uint16_t ms5611_prom(int8_t coef_num)
{
uint8_t rxbuf[2] = { 0, 0 };
#ifdef USE_BARO_SPI_MS5611
ms5611SpiReadCommand(CMD_PROM_RD + coef_num * 2, 2, rxbuf); // send PROM READ command
#else
i2cRead(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_PROM_RD + coef_num * 2, 2, rxbuf); // send PROM READ command
#endif
return rxbuf[0] << 8 | rxbuf[1];
}
STATIC_UNIT_TESTED int8_t ms5611_crc(uint16_t *prom)
{
int32_t i, j;
uint32_t res = 0;
uint8_t crc = prom[7] & 0xF;
prom[7] &= 0xFF00;
bool blankEeprom = true;
for (i = 0; i < 16; i++) {
if (prom[i >> 1]) {
blankEeprom = false;
}
if (i & 1)
res ^= ((prom[i >> 1]) & 0x00FF);
else
res ^= (prom[i >> 1] >> 8);
for (j = 8; j > 0; j--) {
if (res & 0x8000)
res ^= 0x1800;
res <<= 1;
}
}
prom[7] |= crc;
if (!blankEeprom && crc == ((res >> 12) & 0xF))
return 0;
return -1;
}
static uint32_t ms5611_read_adc(void)
{
uint8_t rxbuf[3];
#ifdef USE_BARO_SPI_MS5611
ms5611SpiReadCommand(CMD_ADC_READ, 3, rxbuf); // read ADC
#else
i2cRead(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_ADC_READ, 3, rxbuf); // read ADC
#endif
return (rxbuf[0] << 16) | (rxbuf[1] << 8) | rxbuf[2];
}
static void ms5611_start_ut(void)
{
#ifdef USE_BARO_SPI_MS5611
ms5611SpiWriteCommand(CMD_ADC_CONV + CMD_ADC_D2 + ms5611_osr, 1); // D2 (temperature) conversion start!
#else
i2cWrite(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_ADC_CONV + CMD_ADC_D2 + ms5611_osr, 1); // D2 (temperature) conversion start!
#endif
}
static void ms5611_get_ut(void)
{
ms5611_ut = ms5611_read_adc();
}
static void ms5611_start_up(void)
{
#ifdef USE_BARO_SPI_MS5611
ms5611SpiWriteCommand(CMD_ADC_CONV + CMD_ADC_D2 + ms5611_osr, 1); // D2 (temperature) conversion start!
#else
i2cWrite(BARO_I2C_INSTANCE, MS5611_ADDR, CMD_ADC_CONV + CMD_ADC_D1 + ms5611_osr, 1); // D1 (pressure) conversion start!
#endif
}
static void ms5611_get_up(void)
{
ms5611_up = ms5611_read_adc();
}
STATIC_UNIT_TESTED void ms5611_calculate(int32_t *pressure, int32_t *temperature)
{
uint32_t press;
int64_t temp;
int64_t delt;
int64_t dT = (int64_t)ms5611_ut - ((uint64_t)ms5611_c[5] * 256);
int64_t off = ((int64_t)ms5611_c[2] << 16) + (((int64_t)ms5611_c[4] * dT) >> 7);
int64_t sens = ((int64_t)ms5611_c[1] << 15) + (((int64_t)ms5611_c[3] * dT) >> 8);
temp = 2000 + ((dT * (int64_t)ms5611_c[6]) >> 23);
if (temp < 2000) { // temperature lower than 20degC
delt = temp - 2000;
delt = 5 * delt * delt;
off -= delt >> 1;
sens -= delt >> 2;
if (temp < -1500) { // temperature lower than -15degC
delt = temp + 1500;
delt = delt * delt;
off -= 7 * delt;
sens -= (11 * delt) >> 1;
}
temp -= ((dT * dT) >> 31);
}
press = ((((int64_t)ms5611_up * sens) >> 21) - off) >> 15;
if (pressure)
*pressure = press;
if (temperature)
*temperature = temp;
}