mirror of https://github.com/ArduPilot/ardupilot
272 lines
7.3 KiB
C++
272 lines
7.3 KiB
C++
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
|
||
/*
|
||
* APM_BMP085.cpp - Arduino Library for BMP085 absolute pressure sensor
|
||
* Code by Jordi Mu<4D>oz and Jose Julio. DIYDrones.com
|
||
*
|
||
* This library is free software; you can redistribute it and/or
|
||
* modify it under the terms of the GNU Lesser General Public
|
||
* License as published by the Free Software Foundation; either
|
||
* version 2.1 of the License, or (at your option) any later version.
|
||
*
|
||
* Sensor is conected to I2C port
|
||
* Sensor End of Conversion (EOC) pin is PC7 (30)
|
||
*
|
||
* Variables:
|
||
* RawTemp : Raw temperature data
|
||
* RawPress : Raw pressure data
|
||
*
|
||
* Temp : Calculated temperature (in 0.1<EFBFBD>C units)
|
||
* Press : Calculated pressure (in Pa units)
|
||
*
|
||
* Methods:
|
||
* Init() : Initialization of I2C and read sensor calibration data
|
||
* Read() : Read sensor data and calculate Temperature and Pressure
|
||
* This function is optimized so the main host don<6F>t need to wait
|
||
* You can call this function in your main loop
|
||
* It returns a 1 if there are new data.
|
||
*
|
||
* Internal functions:
|
||
* Command_ReadTemp(): Send commando to read temperature
|
||
* Command_ReadPress(): Send commando to read Pressure
|
||
* ReadTemp() : Read temp register
|
||
* ReadPress() : Read press register
|
||
*
|
||
*
|
||
*/
|
||
|
||
// AVR LibC Includes
|
||
#include <inttypes.h>
|
||
|
||
#include <AP_Common.h>
|
||
#include <AP_Math.h> // ArduPilot Mega Vector/Matrix math Library
|
||
|
||
#include <AP_HAL.h>
|
||
#if CONFIG_HAL_BOARD == HAL_BOARD_APM1 || defined(APM2_BETA_HARDWARE)
|
||
#include "AP_Baro_BMP085.h"
|
||
|
||
extern const AP_HAL::HAL& hal;
|
||
|
||
#define BMP085_ADDRESS 0x77 //(0xEE >> 1)
|
||
#define BMP085_EOC 30 // End of conversion pin PC7
|
||
|
||
// the apm2 hardware needs to check the state of the
|
||
// chip using a direct IO port
|
||
// On APM2 prerelease hw, the data ready port is hooked up to PE7, which
|
||
// is not available to the arduino digitalRead function.
|
||
#if CONFIG_HAL_BOARD == HAL_BOARD_APM2
|
||
#define BMP_DATA_READY() (PINE&0x80)
|
||
#else
|
||
#define BMP_DATA_READY() hal.gpio->read(BMP085_EOC)
|
||
#endif
|
||
|
||
// oversampling 3 gives 26ms conversion time. We then average
|
||
#define OVERSAMPLING 3
|
||
|
||
// Public Methods //////////////////////////////////////////////////////////////
|
||
bool AP_Baro_BMP085::init()
|
||
{
|
||
uint8_t buff[22];
|
||
|
||
hal.gpio->pinMode(BMP085_EOC, GPIO_INPUT);// End Of Conversion (PC7) input
|
||
|
||
// We read the calibration data registers
|
||
if (hal.i2c->readRegisters(BMP085_ADDRESS, 0xAA, 22, buff) != 0) {
|
||
healthy = false;
|
||
return false;
|
||
}
|
||
|
||
ac1 = ((int16_t)buff[0] << 8) | buff[1];
|
||
ac2 = ((int16_t)buff[2] << 8) | buff[3];
|
||
ac3 = ((int16_t)buff[4] << 8) | buff[5];
|
||
ac4 = ((int16_t)buff[6] << 8) | buff[7];
|
||
ac5 = ((int16_t)buff[8] << 8) | buff[9];
|
||
ac6 = ((int16_t)buff[10] << 8) | buff[11];
|
||
b1 = ((int16_t)buff[12] << 8) | buff[13];
|
||
b2 = ((int16_t)buff[14] << 8) | buff[15];
|
||
mb = ((int16_t)buff[16] << 8) | buff[17];
|
||
mc = ((int16_t)buff[18] << 8) | buff[19];
|
||
md = ((int16_t)buff[20] << 8) | buff[21];
|
||
|
||
//Send a command to read Temp
|
||
Command_ReadTemp();
|
||
|
||
BMP085_State = 0;
|
||
|
||
// init raw temo
|
||
RawTemp = 0;
|
||
|
||
healthy = true;
|
||
return true;
|
||
}
|
||
|
||
// Read the sensor. This is a state machine
|
||
// acumulate a new sensor reading
|
||
void AP_Baro_BMP085::accumulate(void)
|
||
{
|
||
if (!BMP_DATA_READY()) {
|
||
return;
|
||
}
|
||
if (BMP085_State == 0) {
|
||
ReadTemp();
|
||
} else {
|
||
ReadPress();
|
||
Calculate();
|
||
}
|
||
BMP085_State++;
|
||
if (BMP085_State == 5) {
|
||
BMP085_State = 0;
|
||
Command_ReadTemp();
|
||
} else {
|
||
Command_ReadPress();
|
||
}
|
||
}
|
||
|
||
|
||
// Read the sensor using accumulated data
|
||
uint8_t AP_Baro_BMP085::read()
|
||
{
|
||
if (_count == 0 && BMP_DATA_READY()) {
|
||
accumulate();
|
||
}
|
||
if (_count == 0) {
|
||
return 0;
|
||
}
|
||
_last_update = hal.scheduler->millis();
|
||
|
||
Temp = _temp_sum / _count;
|
||
Press = _press_sum / _count;
|
||
|
||
_pressure_samples = _count;
|
||
_count = 0;
|
||
_temp_sum = 0;
|
||
_press_sum = 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
float AP_Baro_BMP085::get_pressure() {
|
||
return Press;
|
||
}
|
||
|
||
float AP_Baro_BMP085::get_temperature() {
|
||
return Temp;
|
||
}
|
||
|
||
int32_t AP_Baro_BMP085::get_raw_pressure() {
|
||
return RawPress;
|
||
}
|
||
|
||
int32_t AP_Baro_BMP085::get_raw_temp() {
|
||
return RawTemp;
|
||
}
|
||
|
||
// Private functions: /////////////////////////////////////////////////////////
|
||
|
||
// Send command to Read Pressure
|
||
void AP_Baro_BMP085::Command_ReadPress()
|
||
{
|
||
uint8_t res = hal.i2c->writeRegister(BMP085_ADDRESS, 0xF4,
|
||
0x34+(OVERSAMPLING << 6));
|
||
if (res != 0) {
|
||
healthy = false;
|
||
}
|
||
}
|
||
|
||
// Read Raw Pressure values
|
||
void AP_Baro_BMP085::ReadPress()
|
||
{
|
||
uint8_t buf[3];
|
||
|
||
if (!healthy && hal.scheduler->millis() < _retry_time) {
|
||
return;
|
||
}
|
||
|
||
if (hal.i2c->readRegisters(BMP085_ADDRESS, 0xF6, 3, buf) != 0) {
|
||
_retry_time = hal.scheduler->millis() + 1000;
|
||
hal.i2c->setHighSpeed(false);
|
||
healthy = false;
|
||
return;
|
||
}
|
||
|
||
RawPress = (((uint32_t)buf[0] << 16)
|
||
| ((uint32_t)buf[1] << 8)
|
||
| ((uint32_t)buf[2])) >> (8 - OVERSAMPLING);
|
||
}
|
||
|
||
// Send Command to Read Temperature
|
||
void AP_Baro_BMP085::Command_ReadTemp()
|
||
{
|
||
if (hal.i2c->writeRegister(BMP085_ADDRESS, 0xF4, 0x2E) != 0) {
|
||
healthy = false;
|
||
}
|
||
}
|
||
|
||
// Read Raw Temperature values
|
||
void AP_Baro_BMP085::ReadTemp()
|
||
{
|
||
uint8_t buf[2];
|
||
int32_t _temp_sensor;
|
||
|
||
if (!healthy && hal.scheduler->millis() < _retry_time) {
|
||
return;
|
||
}
|
||
|
||
if (hal.i2c->readRegisters(BMP085_ADDRESS, 0xF6, 2, buf) != 0) {
|
||
_retry_time = hal.scheduler->millis() + 1000;
|
||
hal.i2c->setHighSpeed(false);
|
||
healthy = false;
|
||
return;
|
||
}
|
||
_temp_sensor = buf[0];
|
||
_temp_sensor = (_temp_sensor << 8) | buf[1];
|
||
|
||
RawTemp = _temp_filter.apply(_temp_sensor);
|
||
}
|
||
|
||
|
||
// Calculate Temperature and Pressure in real units.
|
||
void AP_Baro_BMP085::Calculate()
|
||
{
|
||
int32_t x1, x2, x3, b3, b5, b6, p;
|
||
uint32_t b4, b7;
|
||
int32_t tmp;
|
||
|
||
// See Datasheet page 13 for this formulas
|
||
// Based also on Jee Labs BMP085 example code. Thanks for share.
|
||
// Temperature calculations
|
||
x1 = ((int32_t)RawTemp - ac6) * ac5 >> 15;
|
||
x2 = ((int32_t) mc << 11) / (x1 + md);
|
||
b5 = x1 + x2;
|
||
_temp_sum += (b5 + 8) >> 4;
|
||
|
||
// Pressure calculations
|
||
b6 = b5 - 4000;
|
||
x1 = (b2 * (b6 * b6 >> 12)) >> 11;
|
||
x2 = ac2 * b6 >> 11;
|
||
x3 = x1 + x2;
|
||
//b3 = (((int32_t) ac1 * 4 + x3)<<OVERSAMPLING + 2) >> 2; // BAD
|
||
//b3 = ((int32_t) ac1 * 4 + x3 + 2) >> 2; //OK for OVERSAMPLING=0
|
||
tmp = ac1;
|
||
tmp = (tmp*4 + x3)<<OVERSAMPLING;
|
||
b3 = (tmp+2)/4;
|
||
x1 = ac3 * b6 >> 13;
|
||
x2 = (b1 * (b6 * b6 >> 12)) >> 16;
|
||
x3 = ((x1 + x2) + 2) >> 2;
|
||
b4 = (ac4 * (uint32_t) (x3 + 32768)) >> 15;
|
||
b7 = ((uint32_t) RawPress - b3) * (50000 >> OVERSAMPLING);
|
||
p = b7 < 0x80000000 ? (b7 * 2) / b4 : (b7 / b4) * 2;
|
||
|
||
x1 = (p >> 8) * (p >> 8);
|
||
x1 = (x1 * 3038) >> 16;
|
||
x2 = (-7357 * p) >> 16;
|
||
_press_sum += p + ((x1 + x2 + 3791) >> 4);
|
||
|
||
_count++;
|
||
if (_count == 254) {
|
||
_temp_sum *= 0.5;
|
||
_press_sum *= 0.5;
|
||
_count /= 2;
|
||
}
|
||
}
|
||
#endif // CONFIG_HAL_BOARD
|