160 lines
4.0 KiB
C
160 lines
4.0 KiB
C
#ifndef _EC_H_
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#define _EC_H_
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#include <Arduino.h>
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bool ec_flag_measurement_available=false;
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#define EC_PIN_RELAY_PROBE 27
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//#define EC_PIN_ADC 4
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#define EC_ADS_CHANNEL 0
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#define EC_PIN_FREQ 5
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#define EC_PWM_CH 0
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#define EC_RESOLUTION 8
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#define EC_FREQUENCY 5000
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#define EC_CALIB_ARRAY_SIZE 64
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uint16_t ec_calib_array[EC_CALIB_ARRAY_SIZE];
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uint16_t ec_calib_array_pos=0;
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#define EC_CALIB_READ_INTERVAL 100 //interval of reading adc value inside a measurement
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#define EC_ARRAY_SIZE 64
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uint16_t ec_array[EC_ARRAY_SIZE];
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uint16_t ec_array_pos=EC_ARRAY_SIZE;
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unsigned long last_measurement_ec=0;
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#define EC_MEASUREMENT_INTERVAL 10000 //complete filtered measurement every x ms
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//One filtered measurement takes EC_READ_INTERVAL*EC_ARRAY_SIZE*4
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#define EC_READ_INTERVAL 5 //interval of reading adc value inside a measurement
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#define EC_RELAY_SWITCH_SETTLETIME 500 //time until voltage of ec circuit has settled
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const uint16_t ec_centerADCvalue=1909; //adc value when probe resistance is equal to the range resistor (mean of both)
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unsigned long ec_last_change_relay=0; //millis of last relay change
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enum ECState{IDLE,MEASURE};
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ECState ecstate=IDLE;
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float ec_adc;
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float ec_adc_adjusted; //adjusted for reference resistor
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float ec_calib_adc;
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float ec_reference_adc=5889; //adc reference value for the calibration resistor measurement
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bool ec_measurementReady();
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void ec_startMeasurement();
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void ec_setRange(uint8_t range);
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void ec_connectProbe(bool);
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void ec_releaseRelay();
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void ec_setup() {
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ledcSetup(EC_PWM_CH, EC_FREQUENCY, EC_RESOLUTION);
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ledcAttachPin(EC_PIN_FREQ, EC_PWM_CH);
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ledcWrite(EC_PWM_CH, 127); //50% duty cycle
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pinMode(EC_PIN_RELAY_PROBE,OUTPUT); //LOW=Calibration/idle, HIGH=Probe connected
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ec_releaseRelay();
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}
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void ec_loop(unsigned long loopmillis) {
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static unsigned long last_read_ec=0;
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switch (ecstate) {
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case IDLE:
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if (loopmillis>last_measurement_ec+EC_MEASUREMENT_INTERVAL && ecstate==IDLE) { //start measurement if idle
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last_measurement_ec=loopmillis;
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ec_startMeasurement();
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ec_connectProbe(true);
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Serial.println("Measuring EC");
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ecstate=MEASURE;
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}
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break;
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case MEASURE:
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if (ec_measurementReady()) {
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ec_releaseRelay();
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Serial.println("Finished EC");
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ec_adc=getMean(ec_array,EC_ARRAY_SIZE);
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if (isValueArrayOK(ec_calib_array,EC_CALIB_ARRAY_SIZE,0)){
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ec_calib_adc=getMean(ec_calib_array,EC_CALIB_ARRAY_SIZE);
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ec_adc_adjusted=mapf(ec_adc,0,ec_calib_adc,0,ec_reference_adc);
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}
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ec_flag_measurement_available=true;
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ecstate=IDLE;
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}
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break;
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}
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if (ec_array_pos<EC_ARRAY_SIZE) { //measurement running
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if (loopmillis>last_read_ec+EC_READ_INTERVAL) { //take reading into array
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last_read_ec=loopmillis;
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if (loopmillis>ec_last_change_relay+EC_RELAY_SWITCH_SETTLETIME) { //values have settled
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uint16_t value = ADS.readADC(EC_ADS_CHANNEL);
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ec_array[ec_array_pos]=value;
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ec_array_pos++;
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}
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}
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}else{ //measurement not running, then take calibration readings
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if (loopmillis>last_read_ec+EC_CALIB_READ_INTERVAL) { //take reading into array
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last_read_ec=loopmillis;
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if (loopmillis>ec_last_change_relay+EC_RELAY_SWITCH_SETTLETIME) { //values have settled
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uint16_t value = ADS.readADC(EC_ADS_CHANNEL);
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ec_calib_array[ec_calib_array_pos]=value;
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ec_calib_array_pos++;
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ec_calib_array_pos%=EC_CALIB_ARRAY_SIZE;
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}
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}
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}
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}
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void ec_startMeasurement() {
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ec_array_pos=0;
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}
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bool ec_measurementReady(){
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if (ec_array_pos>=EC_ARRAY_SIZE) { //reached end of both arrays
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return true;
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}else{
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return false;
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}
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}
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void ec_connectProbe(bool relay) {
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bool val=digitalRead(EC_PIN_RELAY_PROBE);
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if (val!=relay) { //write only if different
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digitalWrite(EC_PIN_RELAY_PROBE,relay);
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ec_last_change_relay=millis();
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}
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}
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void ec_releaseRelay() {
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digitalWrite(EC_PIN_RELAY_PROBE,LOW);
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ec_last_change_relay=millis();
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}
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#endif |