upm/src/hx711/hx711.cxx
Jon Trulson 97e7f74a8f hx711: remove custom exception and use a standard one
Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
2015-08-13 14:52:24 -07:00

145 lines
4.1 KiB
C++

/*
* 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 <stdexcept>
#include "hx711.h"
using namespace upm;
using namespace std;
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 std::invalid_argument(std::string(__FUNCTION__) +
": Couldn't initialize DATA pin.");
}
this->m_sckPinCtx = mraa_gpio_init(sck);
if (this->m_sckPinCtx == NULL) {
throw std::invalid_argument(std::string(__FUNCTION__) +
": Couldn't initialize CLOCK pin.");
}
error = mraa_gpio_dir (this->m_dataPinCtx, MRAA_GPIO_IN);
if (error != MRAA_SUCCESS) {
throw std::invalid_argument(std::string(__FUNCTION__) +
": Couldn't set direction for DATA pin.");
}
error = mraa_gpio_dir (this->m_sckPinCtx, MRAA_GPIO_OUT);
if (error != MRAA_SUCCESS) {
throw std::invalid_argument(std::string(__FUNCTION__) +
": 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;
}