62 lines
1.3 KiB
C++
62 lines
1.3 KiB
C++
/*
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* PressureWrapper.cpp
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*
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* Created on: 5 Oct 2022
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* Author: evgenymeshcheryakov
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*/
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#include "PressureWrapper.h"
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#include <cstdio>
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static uint8_t crc8(uint8_t *data, size_t size) {
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uint8_t crc = 0x00;
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uint8_t byteCtr;
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//calculates 8-Bit checksum with given polynomial
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for (byteCtr = 0; byteCtr < size; ++byteCtr) {
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crc ^= (data[byteCtr]);
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for (uint8_t bit = 8; bit > 0; --bit) {
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if (crc & 0x80) crc = (crc << 1) ^ 0x131; //P(x)=x^8+x^5+x^4+1 = 0001 0011 0001
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else crc = (crc << 1);
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}
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}
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return crc;
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}
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PressureWrapper::PressureWrapper ()
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{
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NVIC_DisableIRQ(I2C0_IRQn);
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I2C_config config;
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I2C i2c_c(config);
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i2c = &i2c_c;
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}
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PressureWrapper::~PressureWrapper ()
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{
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// TODO Auto-generated destructor stub
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}
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int PressureWrapper::getPressure() {
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int16_t pressure = 0;
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if(!getRawPressure ()) {
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unsigned int i = 0;
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while(i<7200) i++;
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getRawPressure ();
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i = 0;
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}
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if(crc8(data.rBuffer, 2) == data.crc){
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pressure = data.rBuffer[0];
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pressure = pressure << 8;
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pressure |= data.rBuffer[1];
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float result = (float) pressure * 0.95 / 240;
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return (int) result;
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}
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return -255;
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}
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bool PressureWrapper::getRawPressure () {
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uint8_t getMeasurementComm = 0xF1;
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return (i2c->transaction(ADDRESS, &getMeasurementComm, 1, data.rBuffer, 3));
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}
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