I am having some trouble defining an anlog pin in a project.
I am using a 10k pot to simulate PH from a probe so I can work through testing outputs. I have everything working ok with the PH robe, Temp probe and LCD in one sketch. I also have the 10k pot input and simulated PH figure working fine in another sketch.
I am unable setup an anolog pin in the setch that has the PH probe and LCD code and libraries included. I definately have the correct board selected. Code pasted below. Board is a Mega 2560 r3 using IDE version 1.8.12
If I comment out the reference A0 the code will compile. The code for that analog input compiles fine in a sketch on its on. Am I missing something simple?
Appreciate your help.
[code]
// PH Sim & Test code
int sensorPin = A0;
int sensorValue = 0;
int sensorPH = 1;
float decPH = 1.1;
float phLow = 6.5;
float phHi = 8.5;
//----------------------------------------------------------
// LCD Code
#include <Arduino.h>
#include <U8g2lib.h>
#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif
U8G2_ST7920_128X64_F_SW_SPI u8g2(U8G2_R2, /* clock=*/ 21, /* data=*/ 20, /* CS=*/ 53, /* reset=*/ 8);
// End LCD Code
// TEMP SENSOR CODE
#include <OneWire.h>
int DS18S20_Pin = 2; //DS18S20 Signal pin on digital 2
OneWire ds(DS18S20_Pin); // on digital pin 2
//TEMP SENSOR CODE END
#include "DFRobot_PH.h"
#include <EEPROM.h>
#define PH_PIN A1
float voltage, phValue, temperature = 25;
DFRobot_PH ph;
void setup()
{
Serial.begin(115200);
ph.begin();
u8g2.begin(); //Start LCD Screen
}
void loop()
{
static unsigned long timepoint = millis();
if (millis() - timepoint > 1000U) { //time interval: 1s
timepoint = millis();
temperature = readTemperature(); // readtemperature sensor to execute temperature compensation
voltage = analogRead(PH_PIN) / 1024.0 * 5000; // read the voltage
phValue = ph.readPH(voltage, temperature); // convert voltage to pH with temperature compensation
Serial.print("temperature:");
Serial.print(temperature, 1);
Serial.print("^C pH:");
Serial.println(phValue, 2);
}
ph.calibration(voltage, temperature); // calibration
// LCD COde
u8g2.clearBuffer();
u8g2.setFont(u8g2_font_glasstown_nbp_tf);
u8g2.drawStr(0, 10, "Caloundra PH Treatment Tank");
u8g2.drawStr(0, 25, "R PH:");
u8g2.setCursor(28, 25);
u8g2.print(phValue, 2);
u8g2.drawStr(60, 25, "Sim PH:");
u8g2.setCursor(100, 25);
u8g2.print(decPH);
u8g2.drawStr(0, 40, "Temp:");
u8g2.setCursor(38, 40);
u8g2.print(temperature, 1);
u8g2.drawStr(0, 55, "Status:");
u8g2.drawStr(38, 55, "Ciculating");
u8g2.sendBuffer(); // transfer internal memory to the display
//delay(1000); //Commented out delay
//End LCD Code--------------------------------------------------------------------------
// Simulated PH code
sensorPH = map(sensorValue, 0, 1023, 5, 18);
decPH = sensorPH / 10;
sensorValue = analogRead(sensorPin);
// End of Simulated PH Code------------------------------------------------------------
}
float readTemperature()
{
byte data[12];
byte addr[8];
if ( !ds.search(addr)) {
//no more sensors on chain, reset search
ds.reset_search();
return -1000;
}
if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return -1000;
}
if ( addr[0] != 0x10 && addr[0] != 0x28) {
Serial.print("Device is not recognized");
return -1000;
}
ds.reset();
ds.select(addr);
ds.write(0x44, 1); // start conversion, with parasite power on at the end
byte present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
for (int i = 0; i < 9; i++) { // need 9 bytes
data[i] = ds.read();
}
ds.reset_search();
byte MSB = data[1];
byte LSB = data[0];
float tempRead = ((MSB << 8) | LSB); //using two's compliment
float TemperatureSum = tempRead / 16;
return TemperatureSum;
}
[/code]
Error message included below
```
PH___Temp_LCD:4:17: error: 'A0' was not declared in this scope
int sensorPin = A0;
^~
C:\Users\mrobe\OneDrive\Documents\Arduino\PH Meter\PH___Temp_LCD\PH___Temp_LCD.ino:4:17: note: suggested alternative: 'PA0'
int sensorPin = A0;
^~
PA0
exit status 1
'A0' was not declared in this scope
```