hx711: Initial implementation HX711 24bit ADC module

Signed-off-by: Rafael Neri <rafael.neri@gmail.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
This commit is contained in:
Rafael Neri 2015-03-21 15:52:03 -03:00 committed by Mihai Tudor Panu
parent bffecdae89
commit df302ff5db
9 changed files with 390 additions and 1 deletions

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@ -103,6 +103,7 @@ add_executable (groveeldriver-example groveeldriver.cxx)
add_executable (adafruitss-example adafruitss.cxx)
add_executable (adafruitms1438-example adafruitms1438.cxx)
add_executable (adafruitms1438-stepper-example adafruitms1438-stepper.cxx)
add_executable (hx711-example hx711.cxx)
include_directories (${PROJECT_SOURCE_DIR}/src/hmc5883l)
include_directories (${PROJECT_SOURCE_DIR}/src/grove)
@ -186,6 +187,7 @@ include_directories (${PROJECT_SOURCE_DIR}/src/pca9685)
include_directories (${PROJECT_SOURCE_DIR}/src/groveeldriver)
include_directories (${PROJECT_SOURCE_DIR}/src/adafruitss)
include_directories (${PROJECT_SOURCE_DIR}/src/adafruitms1438)
include_directories (${PROJECT_SOURCE_DIR}/src/hx711)
target_link_libraries (hmc5883l-example hmc5883l ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (groveled-example grove ${CMAKE_THREAD_LIBS_INIT})
@ -290,4 +292,4 @@ target_link_libraries (groveeldriver-example groveeldriver ${CMAKE_THREAD_LIBS_I
target_link_libraries (adafruitss-example adafruitss ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (adafruitms1438-example adafruitms1438 ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (adafruitms1438-stepper-example adafruitms1438 ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (hx711-example hx711 ${CMAKE_THREAD_LIBS_INIT})

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examples/c++/hx711.cxx Normal file
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/*
*
* Author: Rafael da Mata Neri <rafael.neri@gmail.com>
* Copyright (c) 2015 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 <signal.h>
//! [Interesting]
#include "hx711.h"
int
main(int argc, char **argv)
{
upm::HX711 *scale = new upm::HX711(3, 2);
// 2837: value obtained via calibration
scale->setScale(2837);
scale->tare();
std::cout << scale->getUnits() << std::endl;
return 0;
}
//! [Interesting]

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/*
*
* Author: Rafael da Mata Neri <rafael.neri@gmail.com>
* Copyright (c) 2015 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.
*/
var hx711 = require('jsupm_hx711');
// Instantiate a HX711 data on digital pin D3 and clock on digital pin D2
var scale = new hx711.HX711(3, 2);
setTimeout(function(){
// 2837: value obtained via calibration
scale.setScale(2837);
scale.tare(2);
setInterval(function(){
console.log(scale.getUnits());
}, 1000);
}, 1000);

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src/hx711/CMakeLists.txt Normal file
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set (libname "hx711")
set (libdescription "HX711 24bit ADC")
set (module_src ${libname}.cxx)
set (module_h ${libname}.h)
upm_module_init()

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src/hx711/hx711.cxx Normal file
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/*
*
* Author: Rafael da Mata Neri <rafael.neri@gmail.com>
* Copyright (c) 2015 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 <iostream>
#include <fstream>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "hx711.h"
using namespace upm;
using namespace std;
struct HX711Exception : public std::exception {
std::string message;
HX711Exception (std::string msg) : message (msg) { }
~HX711Exception () throw () { }
const char* what() const throw () { return message.c_str(); }
};
HX711::HX711(uint8_t data, uint8_t sck, uint8_t gain) {
mraa_result_t error = MRAA_SUCCESS;
this->m_dataPinCtx = mraa_gpio_init(data);
if (this->m_dataPinCtx == NULL) {
throw HX711Exception ("Couldn't initilize DATA pin.");
}
this->m_sckPinCtx = mraa_gpio_init(sck);
if (this->m_sckPinCtx == NULL) {
throw HX711Exception ("Couldn't initilize CLOCK pin.");
}
error = mraa_gpio_dir (this->m_dataPinCtx, MRAA_GPIO_IN);
if (error != MRAA_SUCCESS) {
throw HX711Exception ("Couldn't set direction for DATA pin.");
}
error = mraa_gpio_dir (this->m_sckPinCtx, MRAA_GPIO_OUT);
if (error != MRAA_SUCCESS) {
throw HX711Exception ("Couldn't set direction for CLOCK pin.");
}
this->setGain(gain);
}
HX711::~HX711() {
mraa_result_t error = MRAA_SUCCESS;
error = mraa_gpio_close (this->m_dataPinCtx);
if (error != MRAA_SUCCESS) {
mraa_result_print(error);
}
error = mraa_gpio_close (this->m_sckPinCtx);
if (error != MRAA_SUCCESS) {
mraa_result_print(error);
}
}
unsigned long HX711::read() {
unsigned long Count = 0;
while (mraa_gpio_read(this->m_dataPinCtx));
for (int i=0; i<GAIN; i++)
{
mraa_gpio_write(this->m_sckPinCtx, 1);
Count = Count << 1;
mraa_gpio_write(this->m_sckPinCtx, 0);
if(mraa_gpio_read(this->m_dataPinCtx))
{
Count++;
}
}
mraa_gpio_write(this->m_sckPinCtx, 1);
Count = Count ^ 0x800000;
mraa_gpio_write(this->m_sckPinCtx, 0);
return (Count);
}
void HX711::setGain(uint8_t gain){
switch (gain) {
case 128: // channel A, gain factor 128
GAIN = 24;
break;
case 64: // channel A, gain factor 64
GAIN = 26;
break;
case 32: // channel B, gain factor 32
GAIN = 25;
break;
}
mraa_gpio_write(this->m_sckPinCtx, 0);
read();
}
unsigned long HX711::readAverage(uint8_t times){
unsigned long sum = 0;
for (uint8_t i = 0; i < times; i++) {
sum += read();
}
return sum / times;
}
double HX711::getValue(uint8_t times){
return readAverage(times) - OFFSET;
}
float HX711::getUnits(uint8_t times){
return getValue(times) / SCALE;
}
void HX711::tare(uint8_t times){
double sum = readAverage(times);
setOffset(sum);
}
void HX711::setScale(float scale){
SCALE = scale;
}
void HX711::setOffset(long offset){
OFFSET = offset;
}

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src/hx711/hx711.h Normal file
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/*
*
* Author: Rafael da Mata Neri <rafael.neri@gmail.com>
* Copyright (c) 2015 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.
*/
#pragma once
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <mraa/gpio.h>
namespace upm {
/**
* @brief HX711 24bit ADC library
* @defgroup hx711 libupm-hx711
*/
/**
* @brief C++ API for HX711
*
* [HX711](http://www.dfrobot.com/image/data/SEN0160/hx711_english.pdf) is
* a precision 24-bit analog- to-digital converter (ADC) designed for weigh
* scales and industrial control applications to interface directly with a
* bridge sensor. This module was tested on the Intel Galileo Gen2.
*
* @ingroup hx711 hx711
* @snippet hx711.cxx Interesting
* @image html hx711.jpeg
*/
class HX711 {
public:
/**
* HX711 module constructor
*
* @param data define the data pin
* @param sck define the clock pin
* @param gain define the gain factor
* Valid values are 128 or 64 for channel A; channel B works with 32 gain factor only
*/
HX711(uint8_t data, uint8_t sck, uint8_t gain = 128);
/**
* HX711 module Destructor
*/
~HX711();
/**
* Waits for the chip to be ready and returns a reading
*
* @return raw adc read
*/
unsigned long read();
/**
* Set the gain factor; takes effect only after a call to read()
* channel A can be set for a 128 or 64 gain; channel B has a fixed 32 gain
* depending on the parameter, the channel is also set to either A or B
* @param gain define the gain factor
*/
void setGain(uint8_t gain = 128);
/**
* Returns an average reading
* @param times define how many times to read
* @return the avarage reading
*/
unsigned long readAverage(uint8_t times = 10);
/**
* Returns (readAverage() - OFFSET)
* @param times define how many readings to do
* @return the current value without the tare weight
*/
double getValue(uint8_t times = 10);
/**
* Returns getValue() divided by SCALE
* @param times define how many readings to do
* @return the raw value divided by a value obtained via calibration
*/
float getUnits(uint8_t times = 1);
/**
* Set the OFFSET value for tare weight
* @param times define how many times to read the tare value
*/
void tare(uint8_t times = 10);
/**
* Set the SCALE value
* This value is used to convert the raw data to "human readable" data (measure units)
* @param scale value obtained via calibration
*/
void setScale(float scale = 1.f);
private:
mraa_gpio_context m_sckPinCtx; // Power Down and Serial Clock Input Pin
mraa_gpio_context m_dataPinCtx; // Serial Data Output Pin
uint8_t GAIN; // amplification factor
unsigned long OFFSET; // used for tare weight
float SCALE; // used to return weight in grams, kg, ounces, whatever
/**
* Set the OFFSET value
* The value that's subtracted from the actual reading (tare weight)
* @param scale value obtained via calibration
*/
void setOffset(long offset = 0);
};
}

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src/hx711/jsupm_hx711.i Normal file
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//! [Interesting]
%module jsupm_hx711
%include "../upm.i"
%{
#include "hx711.h"
%}
%include "hx711.h"
//! [Interesting]

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src/hx711/pyupm_hx711.i Normal file
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%module pyupm_hx711
%include "../upm.i"
%include "stdint.i"
%feature("autodoc", "3");
%include "hx711.h"
%{
#include "hx711.h"
%}