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bmpx8x: rewrite in C; FTI; C++ wraps C

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This driver has been rewritten from scratch.

See docs/apichanges.md for a list of API compatibility changes
compared to the original driver.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
This commit is contained in:
Jon Trulson
2017-04-04 17:48:41 -06:00
parent 8d43c431f2
commit c57a0d2c30
17 changed files with 1346 additions and 424 deletions
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234
src/bmpx8x/bmpx8x.cxx
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@@ -1,6 +1,11 @@
/*
* Author: Jon Trulson <jtrulson@ics.com>
* Copyright (c) 2017 Intel Corporation.
*
* This driver was rewritten based on the original driver written by:
* Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* The MIT License
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
@@ -31,202 +36,85 @@
#include "bmpx8x.hpp"
using namespace upm;
using namespace std;
BMPX8X::BMPX8X (int bus, int devAddr, uint8_t mode) : m_controlAddr(devAddr), m_i2ControlCtx(bus) {
m_name = "BMPX8X";
mraa::Result ret = m_i2ControlCtx.address(m_controlAddr);
if (ret != mraa::SUCCESS) {
throw std::invalid_argument(std::string(__FUNCTION__) +
": mraa_i2c_address() failed");
return;
}
if (i2cReadReg_8 (0xD0) != 0x55) {
throw std::runtime_error(std::string(__FUNCTION__) +
": Invalid chip ID");
return;
}
if (mode > BMP085_ULTRAHIGHRES) {
mode = BMP085_ULTRAHIGHRES;
}
oversampling = mode;
/* read calibration data */
ac1 = i2cReadReg_16 (BMP085_CAL_AC1);
ac2 = i2cReadReg_16 (BMP085_CAL_AC2);
ac3 = i2cReadReg_16 (BMP085_CAL_AC3);
ac4 = i2cReadReg_16 (BMP085_CAL_AC4);
ac5 = i2cReadReg_16 (BMP085_CAL_AC5);
ac6 = i2cReadReg_16 (BMP085_CAL_AC6);
b1 = i2cReadReg_16 (BMP085_CAL_B1);
b2 = i2cReadReg_16 (BMP085_CAL_B2);
mb = i2cReadReg_16 (BMP085_CAL_MB);
mc = i2cReadReg_16 (BMP085_CAL_MC);
md = i2cReadReg_16 (BMP085_CAL_MD);
BMPX8X::BMPX8X (int bus, int addr) :
m_bmpx8x(bmpx8x_init(bus, addr))
{
if (!m_bmpx8x)
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_init() failed");
}
int32_t
BMPX8X::getPressure () {
int32_t UT, UP, B3, B5, B6, X1, X2, X3, p;
uint32_t B4, B7;
UT = getTemperatureRaw();
UP = getPressureRaw();
B5 = computeB5(UT);
// do pressure calcs
B6 = B5 - 4000;
X1 = ((int32_t)b2 * ( (B6 * B6)>>12 )) >> 11;
X2 = ((int32_t)ac2 * B6) >> 11;
X3 = X1 + X2;
B3 = ((((int32_t)ac1*4 + X3) << oversampling) + 2) / 4;
X1 = ((int32_t)ac3 * B6) >> 13;
X2 = ((int32_t)b1 * ((B6 * B6) >> 12)) >> 16;
X3 = ((X1 + X2) + 2) >> 2;
B4 = ((uint32_t)ac4 * (uint32_t)(X3 + 32768)) >> 15;
B7 = ((uint32_t)UP - B3) * (uint32_t)( 50000UL >> oversampling );
if (B7 < 0x80000000) {
p = (B7 * 2) / B4
;
} else {
p = (B7 / B4) * 2;
}
X1 = (p >> 8) * (p >> 8);
X1 = (X1 * 3038) >> 16;
X2 = (-7357 * p) >> 16;
p = p + ((X1 + X2 + (int32_t)3791)>>4);
return p;
BMPX8X::~BMPX8X()
{
bmpx8x_close(m_bmpx8x);
}
int32_t
BMPX8X::getPressureRaw () {
uint32_t raw;
i2cWriteReg (BMP085_CONTROL, BMP085_READPRESSURECMD + (oversampling << 6));
if (oversampling == BMP085_ULTRALOWPOWER) {
usleep(5000);
} else if (oversampling == BMP085_STANDARD) {
usleep(8000);
} else if (oversampling == BMP085_HIGHRES) {
usleep(14000);
} else {
usleep(26000);
}
raw = i2cReadReg_16 (BMP085_PRESSUREDATA);
raw <<= 8;
raw |= i2cReadReg_8 (BMP085_PRESSUREDATA + 2);
raw >>= (8 - oversampling);
return raw;
void BMPX8X::init(BMPX8X_OSS_T oss)
{
if (bmpx8x_devinit(m_bmpx8x, oss))
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_devinit() failed");
}
int16_t
BMPX8X::getTemperatureRaw () {
i2cWriteReg (BMP085_CONTROL, BMP085_READTEMPCMD);
usleep(5000);
return i2cReadReg_16 (BMP085_TEMPDATA);
void BMPX8X::update()
{
if (bmpx8x_update(m_bmpx8x))
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_update() failed");
}
float
BMPX8X::getTemperature () {
int32_t UT, B5; // following ds convention
float temp;
UT = getTemperatureRaw ();
B5 = computeB5 (UT);
temp = (B5 + 8) >> 4;
temp /= 10;
return temp;
void BMPX8X::reset()
{
if (bmpx8x_reset(m_bmpx8x))
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_reset() failed");
}
int32_t
BMPX8X::getSealevelPressure(float altitudeMeters) {
float pressure = getPressure ();
return (int32_t)(pressure / pow(1.0-altitudeMeters/44330, 5.255));
void BMPX8X::setOversampling(BMPX8X_OSS_T oss)
{
bmpx8x_set_oversampling(m_bmpx8x, oss);
}
float
BMPX8X::getAltitude (float sealevelPressure) {
float altitude;
float pressure = getPressure ();
altitude = 44330 * (1.0 - pow(pressure /sealevelPressure,0.1903));
return altitude;
uint8_t BMPX8X::readReg(uint8_t reg)
{
return bmpx8x_read_reg(m_bmpx8x, reg);
}
int BMPX8X::readRegs(uint8_t reg, uint8_t *buffer, int len)
{
int rv = bmpx8x_read_regs(m_bmpx8x, reg, buffer, len);
if (rv < 0)
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_read_regs() failed");
int
BMPX8X::getTemperatureCelsius() {
return static_cast<int>(getTemperature() + 0.5);
return rv;
}
const char*
BMPX8X::getModuleName() {
return m_name.c_str();
void BMPX8X::writeReg(uint8_t reg, uint8_t val)
{
if (bmpx8x_write_reg(m_bmpx8x, reg, val))
throw std::runtime_error(string(__FUNCTION__)
+ ": bmpx8x_write_reg() failed");
}
int32_t
BMPX8X::computeB5(int32_t UT) {
int32_t X1 = (UT - (int32_t)ac6) * ((int32_t)ac5) >> 15;
int32_t X2 = ((int32_t)mc << 11) / (X1+(int32_t)md);
return X1 + X2;
int BMPX8X::getPressure()
{
return bmpx8x_get_pressure(m_bmpx8x);
}
mraa::Result
BMPX8X::i2cWriteReg (uint8_t reg, uint8_t value) {
mraa::Result error = mraa::SUCCESS;
uint8_t data[2] = { reg, value };
error = m_i2ControlCtx.address (m_controlAddr);
error = m_i2ControlCtx.write (data, 2);
return error;
float BMPX8X::getTemperature()
{
return bmpx8x_get_temperature(m_bmpx8x);
}
uint16_t
BMPX8X::i2cReadReg_16 (int reg) {
uint16_t data;
m_i2ControlCtx.address(m_controlAddr);
m_i2ControlCtx.writeByte(reg);
m_i2ControlCtx.address(m_controlAddr);
m_i2ControlCtx.read((uint8_t *)&data, 0x2);
uint8_t high = (data & 0xFF00) >> 8;
data = (data << 8) & 0xFF00;
data |= high;
return data;
int BMPX8X::getSealevelPressure(float altitudeMeters)
{
return bmpx8x_get_sealevel_pressure(m_bmpx8x, altitudeMeters);
}
uint8_t
BMPX8X::i2cReadReg_8 (int reg) {
uint8_t data;
m_i2ControlCtx.address(m_controlAddr);
m_i2ControlCtx.writeByte(reg);
m_i2ControlCtx.address(m_controlAddr);
m_i2ControlCtx.read(&data, 0x1);
return data;
float BMPX8X::getAltitude(int sealevelPressure)
{
return bmpx8x_get_altitude(m_bmpx8x, sealevelPressure);
}