htu21d: sensor added

Signed-off-by: William Penner <william.penner@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
William Penner 2014-11-21 07:46:12 -08:00 committed by Brendan Le Foll
parent 9ab215b6fd
commit b53881a8d6
8 changed files with 513 additions and 0 deletions

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@ -42,6 +42,7 @@ add_executable (joystick12-example joystick12-example.cxx)
add_executable (lol-example lol-example.cxx)
add_executable (nrf_ble_broadcast-example ble_broadcast.cxx)
add_executable (tsl2561-example tsl2561.cxx)
add_executable (htu21d-example htu21d.cxx)
include_directories (${PROJECT_SOURCE_DIR}/src/hmc5883l)
include_directories (${PROJECT_SOURCE_DIR}/src/grove)
@ -75,6 +76,7 @@ include_directories (${PROJECT_SOURCE_DIR}/src/lsm303)
include_directories (${PROJECT_SOURCE_DIR}/src/joystick12)
include_directories (${PROJECT_SOURCE_DIR}/src/lol)
include_directories (${PROJECT_SOURCE_DIR}/src/tsl2561)
include_directories (${PROJECT_SOURCE_DIR}/src/htu21d)
target_link_libraries (hmc5883l-example hmc5883l ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (groveled-example grove ${CMAKE_THREAD_LIBS_INIT})
@ -120,3 +122,4 @@ target_link_libraries (joystick12-example joystick12 ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (lol-example lol ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (nrf_ble_broadcast-example nrf24l01 ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (tsl2561-example tsl2561 ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (htu21d-example htu21d ${CMAKE_THREAD_LIBS_INIT})

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examples/htu21d.cxx Executable file
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/*
* Author: William Penner <william.penner@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* 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 <unistd.h>
#include <iostream>
#include "htu21d.h"
#include <signal.h>
int doWork = 0;
upm::HTU21D *sensor = NULL;
void
sig_handler(int signo)
{
printf("got signal\n");
if (signo == SIGINT) {
printf("exiting application\n");
doWork = 1;
}
}
int
main(int argc, char **argv)
{
//! [Interesting]
int32_t humidity = 0;
int32_t temperature = 0;
int32_t compRH = 0;
sensor = new upm::HTU21D(0, HTU21D_I2C_ADDRESS);
while (!doWork) {
humidity = sensor->getRHumidity(&temperature);
compRH = sensor->getCompRH();
std::cout << "humidity value = " <<
(float)humidity / 1000.0 <<
", temperature value = " <<
(float)temperature / 1000.0 <<
", compensated RH value = " <<
(float)compRH / 1000.0 << std::endl;
usleep (100000);
}
//! [Interesting]
std::cout << "exiting application" << std::endl;
delete sensor;
return 0;
}

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set (libname "htu21d")
set (libdescription "libupm Humidity Sensor")
set (module_src ${libname}.cpp)
set (module_h ${libname}.h)
upm_module_init()

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src/htu21d/htu21d.cpp Normal file
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/*
* Author: William Penner <william.penner@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* This driver supports the HTU21D digital humidity and temperature
* sensor. The datasheet is available from:
* http://www.meas-spec.com/downloads/HTU21D.pdf
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <iostream>
#include <unistd.h>
#include <stdlib.h>
#include "htu21d.h"
using namespace upm;
HTU21D::HTU21D(int bus, int devAddr) {
m_temperature = 0;
m_humidity = 0;
m_name = HTU21D_NAME;
m_controlAddr = devAddr;
m_bus = bus;
m_i2ControlCtx = mraa_i2c_init(m_bus);
mraa_result_t ret = mraa_i2c_address(m_i2ControlCtx, m_controlAddr);
if (ret != MRAA_SUCCESS) {
fprintf(stderr, "Error accessing i2c bus\n");
}
}
HTU21D::~HTU21D() {
mraa_i2c_stop(m_i2ControlCtx);
}
int32_t
HTU21D::htu21_temp_ticks_to_millicelsius(int ticks)
{
ticks &= ~0x0003; /* clear status bits */
/*
* Formula T = -46.85 + 175.72 * ST / 2^16 from datasheet p14,
* optimized for integer fixed point (3 digits) arithmetic
*/
return ((21965 * (int32_t)ticks) >> 13) - 46850;
}
int32_t
HTU21D::htu21_rh_ticks_to_per_cent_mille(int ticks)
{
ticks &= ~0x0003; /* clear status bits */
/*
* Formula RH = -6 + 125 * SRH / 2^16 from datasheet p14,
* optimized for integer fixed point (3 digits) arithmetic
*/
return ((15625 * (int32_t)ticks) >> 13) - 6000;
}
int
HTU21D::sampleData(void)
{
uint32_t itemp;
itemp = i2cReadReg_16(HTU21D_T_MEASUREMENT_HM);
m_temperature = htu21_temp_ticks_to_millicelsius(itemp);
itemp = i2cReadReg_16(HTU21D_RH_MEASUREMENT_HM);
m_humidity = htu21_rh_ticks_to_per_cent_mille(itemp);
return 0;
}
int32_t
HTU21D::getTemperature(void)
{
return m_temperature;
}
int32_t
HTU21D::getHumidity(void)
{
return m_humidity;
}
/*
* This is the primary function to read the data. It will initiate
* a measurement cycle and will then return both the humidity and
* temperature values. piTemperature can be NULL.
*/
int32_t
HTU21D::getRHumidity(int32_t* piTemperature)
{
sampleData();
if (NULL != piTemperature)
*piTemperature = m_temperature;
return m_humidity;
}
/*
* Use the compensation equation from the datasheet to correct the
* current reading
* RHcomp = RHactualT + (25 - Tactual) * CoeffTemp
* RHcomp is in units of %RH * 1000
*/
int32_t
HTU21D::getCompRH(void)
{
return m_humidity + (25000 - m_temperature) * 3 / 20;
}
/*
* Test function: when reading the HTU21D many times rapidly should
* result in a temperature increase. This test will verify that the
* value is changing from read to read
*/
int
HTU21D::testSensor(void)
{
int iError = 0;
int i, j;
int32_t iTemp, iHum;
int32_t iTempMax, iTempMin;
int32_t iHumMax, iHumMin;
int32_t iHumFirst, iTempFirst;
fprintf(stdout, "Executing Sensor Test.\n Reading registers 100 times to look for operation\n" );
iHum = getRHumidity(&iTemp);
iTempFirst = iTempMax = iTempMin = iTemp;
iHumFirst = iHumMax = iHumMin = iHum;
for (i=0; i < 100; i++) {
iHum = getRHumidity(&iTemp);
if (iHum < iHumMin) iHumMin = iHum;
if (iHum > iHumMax) iHumMax = iHum;
if (iTemp < iTempMin) iTempMin = iTemp;
if (iTemp > iTempMax) iTempMax = iTemp;
// fprintf(stdout, "Temp: %d Humidity: %d\n", iTemp, iHum);
}
if ((iTemp - iTempFirst) <= 0) {
fprintf(stdout, "! Temperature should have increased, but didn't\n" );
iError++;
}
if (iHumMin == iHumMax) {
fprintf(stdout, "! Humidity was unchanged - not working?\n" );
iError++;
}
if (iTempMin == iTempMax) {
fprintf(stdout, "! Temperature was unchanged - not working?\n" );
iError++;
}
if (iError == 0) {
fprintf(stdout, " Device appears functional\n" );
}
fprintf(stdout, " Test complete\n" );
return iError;
}
/*
* Functions to read and write data to the i2c device
*/
mraa_result_t
HTU21D::i2cReadRegValue(int reg, uint32_t* puint32, int ibytes) {
uint32_t data = 0;
if (ibytes > 4)
ibytes = 4;
mraa_i2c_address(m_i2ControlCtx, m_controlAddr);
mraa_i2c_write_byte(m_i2ControlCtx, reg);
mraa_i2c_address(m_i2ControlCtx, m_controlAddr);
mraa_i2c_read(m_i2ControlCtx, (uint8_t *)&data, ibytes);
fprintf(stdout, "reg data = %08x\n", data);
*puint32 = be32toh(data) >> ((4-ibytes) * 8);
fprintf(stdout, "reg return = %08x\n", *puint32);
return MRAA_SUCCESS;
}
mraa_result_t
HTU21D::i2cWriteReg (uint8_t reg, uint8_t value) {
mraa_result_t error = MRAA_SUCCESS;
uint8_t data[2] = { reg, value };
error = mraa_i2c_address (m_i2ControlCtx, m_controlAddr);
error = mraa_i2c_write (m_i2ControlCtx, data, 2);
return error;
}
/*
* Function to read 16 bits starting at reg. This function
* was replaced due to functionality of using read() to
* access i2c data.
*/
uint16_t
HTU21D::i2cReadReg_16 (int reg) {
uint16_t data;
mraa_i2c_address(m_i2ControlCtx, m_controlAddr);
data = (uint16_t)mraa_i2c_read_byte_data(m_i2ControlCtx, reg) << 8;
data |= (uint16_t)mraa_i2c_read_byte_data(m_i2ControlCtx, reg+1);
return data;
}
/*
* Function to read 8 bits starting at reg. This function
* was replaced due to functionality of using read() to
* access i2c data.
*/
uint8_t
HTU21D::i2cReadReg_8 (int reg) {
mraa_i2c_address(m_i2ControlCtx, m_controlAddr);
return mraa_i2c_read_byte_data(m_i2ControlCtx, reg);
}

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/*
* Author: William Penner <william.penner@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* Based on code adapted from the kernel HTU21 driver and
* code by: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#pragma once
#include <string>
#include <mraa/i2c.h>
#include <math.h>
#define HTU21D_NAME "htu21d"
#define HTU21D_I2C_ADDRESS 0x40
/* HTU21 Commands */
#define HTU21D_T_MEASUREMENT_HM 0xE3
#define HTU21D_RH_MEASUREMENT_HM 0xE5
namespace upm {
/**
* @brief HTU21D humidity sensor library
* @defgroup htu21d libupm-htu21
*/
/**
* @brief C++ API for HTU21D chip (Atmospheric Pressure Sensor)
*
* Measurement Specialties [HTU21D]
* (http://www.meas-spec.com/downloads/HTU21D.pdf)
* is a digital humidity sensor with temperature output.
* RH will report between 0 and 100% and temperature range is
* -40 to +125 degC
*
* @ingroup htu21d i2c
* @snippet htu21d.cxx Interesting
* @image html htu21d.jpeg
*/
class HTU21D {
public:
/**
* Instanciates a HTU21D object
*
* @param bus number of used bus
* @param devAddr address of used i2c device
* @param mode HTU21D oversampling
*/
HTU21D (int bus=0, int devAddr=HTU21D_I2C_ADDRESS);
/**
* HTU21D object destructor, basicaly it close i2c connection.
*/
~HTU21D ();
/**
* Initiate a temp/pressure mesasurement and wait for function
* to complete. The humidity and temp registers can be read
* after this call.
*/
int sampleData(void);
/**
* Get the current measured humidity [RH * 1000]
* To convert to Relative Humidity, divide by 1000
*
*/
int32_t getHumidity(void);
/**
* Get the humidity cell temperature [degC * 1000]
* To convert to Temperature, divide by 1000
*/
int32_t getTemperature(void);
/**
* Reads both temperature and humidity together
* To convert to Relative Humidity, divide by 1000
* To convert to Temperature, divide by 1000
*
* @param pointer to int32_t buffer for temp
*/
int32_t getRHumidity(int32_t* iTemperature);
/**
* Using the current humidity and temperature the function
* will calculate the compensated RH using the equation from
* the datasheet.
*/
int32_t getCompRH(void);
/**
* Function intended to test the device and verify it
* is correctly operating.
*
*/
int testSensor(void);
/**
* Read 1 to 4 bytes from i2c registers
*
* @param reg address of a register
* @param puint32 pointer to buffer for register data
* @param ibytes number of bytes to be returned
*/
mraa_result_t i2cReadRegValue (int reg, uint32_t* puint32, int ibytes);
/**
* Read two bytes register
*
* @param reg address of a register
*/
uint16_t i2cReadReg_16 (int reg);
/**
* Write to one byte register
*
* @param reg address of a register
* @param value byte to be written
*/
mraa_result_t i2cWriteReg (uint8_t reg, uint8_t value);
/**
* Read one byte register
*
* @param reg address of a register
*/
uint8_t i2cReadReg_8 (int reg);
private:
/**
* Convert temp register to value * 1000
*/
int32_t htu21_temp_ticks_to_millicelsius(int ticks);
/**
* Convert temp register to value * 1000
*/
int32_t htu21_rh_ticks_to_per_cent_mille(int ticks);
std::string m_name;
int m_controlAddr;
int m_bus;
mraa_i2c_context m_i2ControlCtx;
int32_t m_temperature;
int32_t m_humidity;
};
}

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%module jsupm_htu21d
%include "../upm.i"
%{
#include "htu21d.h"
%}
%include "htu21d.h"

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src/htu21d/pyupm_htu21d.i Normal file
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%module pyupm_htu21d
%include "../upm.i"
%feature("autodoc", "3");
#ifdef DOXYGEN
%include "htu21d_doc.i"
#endif
%include "htu21d.h"
%{
#include "htu21d.h"
%}