I'm having trouble with a timer. I'm making a brewing system and I'm heating up water until it gets to a temp and then keeping it there for an amount of time and then heating up to a different temp.
Below is my code. The problem I'm having is that it seems once I hit the target temperature the time that is being recorded is continually looping so it keeps updating the timer.. So when I do the start time minus the time that it hit the correct temperature is the same over and over.
Thanks for any help
#include <OneWire.h>
// OneWire DS18S20, DS18B20, DS1822 Temperature Example
//
// http://www.pjrc.com/teensy/td_libs_OneWire.html
//
// The DallasTemperature library can do all this work for you!
// http://milesburton.com/Dallas_Temperature_Control_Library
//User Inputs:
//MASH TEMP
const int MASHTEMP = 82; // Desired Mash Temp(deg F)
//MASH TIME
const int MASHTIME = 10000; //Desired Mash Time(milli sec.)
//BOIL TIME
const int BOILTIME = 10000; //Desired Boil Time(milli sec.)
boolean MashTimer = false; //used for MASH TIME
long MashStartTime; //used for MASH TIME
boolean BoilTimer = false; //used for BOIL TIME
long BoilStartTime; //used for BOIL TIME
int MASHTANKTEMP;
long startTime;//begins timer
OneWire ds(10); // on pin 10 (a 4.7K resistor is necessary)
const int heater = 12;
void setup(void) {
Serial.begin(9600);
pinMode(heater,OUTPUT);
}
void loop(void) {
startTime = millis();
byte i;
byte present = 0;
byte type_s;
byte data[12];
byte addr[8];
float celsius, fahrenheit, currentMashTemp;
if ( !ds.search(addr)) {
Serial.println(" ");
Serial.println();
ds.reset_search();
delay(250);
return;
}
Serial.print("ROM =");
for( i = 0; i < 8; i++) {
Serial.write(' ');
Serial.print(addr[i], HEX);
}
if (OneWire::crc8(addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return;
}
Serial.println();
// the first ROM byte indicates which chip
switch (addr[0]) {
case 0x10:
Serial.println(" Chip = DS18S20"); // or old DS1820
type_s = 1;
break;
case 0x28:
Serial.println(" Chip = DS18B20");
type_s = 0;
break;
case 0x22:
Serial.println(" Chip = DS1822");
type_s = 0;
break;
default:
Serial.println("Device is not a DS18x20 family device.");
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44, 1); // start conversion, with parasite power on at the end
delay(1000); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
Serial.print(" Data = ");
Serial.print(present, HEX);
Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
Serial.print(data[i], HEX);
Serial.print(" ");
}
Serial.print(" CRC=");
Serial.print(OneWire::crc8(data, 8), HEX);
Serial.println();
// Convert the data to actual temperature
// because the result is a 16 bit signed integer, it should
// be stored to an "int16_t" type, which is always 16 bits
// even when compiled on a 32 bit processor.
int16_t raw = (data[1] << 8) | data[0];
if (type_s) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
// "count remain" gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
}
} else {
byte cfg = (data[4] & 0x60);
// at lower res, the low bits are undefined, so let's zero them
if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
//// default is 12 bit resolution, 750 ms conversion time
}
celsius = (float)raw / 16.0;
fahrenheit = celsius * 1.8 + 32.0;
MASHTANKTEMP = fahrenheit;
Serial.print(" MASHTANKTEMP ");
Serial.print( MASHTANKTEMP );
Serial.print(" startTime" );
Serial.print(startTime);
;
if (MASHTANKTEMP < MASHTEMP && MashTimer < MASHTIME) { // Heat on before and during mash
digitalWrite (heater,HIGH);
}
if (MASHTANKTEMP > MASHTEMP && MashTimer < MASHTIME) { // heat off during mashing
digitalWrite (heater,LOW);
}
if(MASHTANKTEMP >= (MASHTEMP - 2.0) && MASHTANKTEMP <= (MASHTEMP + 2.0) && MashTimer < MASHTIME){ // starts timer for mash
MashTimer = true;
}
if (MashTimer){
MashStartTime = millis(); // starts mash timer
//Test to see if timer is working correctly:
Serial.print(" MashStartTime ");
Serial.print(MashStartTime);
Serial.print("time elapsed");
Serial.print(startTime - MashStartTime);
}
if ((startTime-MashStartTime) >= MASHTIME && BoilTimer == false){ //mash is complete and before boil timer starts turns on heat
digitalWrite(heater,HIGH);
}
// THE FOLLOWING CONTINUES AND CONTROLS THE BOIL PROCESS (PROCESS #3)
if ((startTime-MashStartTime) > MASHTIME && MASHTANKTEMP >= 85 && MASHTANKTEMP <= 95){
// Triggers after mash time is complete and once temp range is reached.
BoilTimer == true; //SHOULD only trigger the FIRST time this condition is met, not each time
}
if (BoilTimer){ ////Starts the Boil Timer if condition above is met (Boil Temp is reached, boolean Boil Timer = true)
BoilStartTime = millis();
}
if ((startTime-BoilStartTime) >= BOILTIME && BoilTimer == true){ //Greater than or equal to ensures that you will hit and trigger this function
digitalWrite(heater,LOW);
}
}
Here is what I'm getting when I'm receiving the temps and times from my arduino.
ROM = 28 D1 5E B6 6 0 0 93
Chip = DS18B20
Data = 1 67 2 4B 46 7F FF 9 10 7C CRC=7C
MASHTANKTEMP 101 startTime49548 MashStartTime 50592time elapsed-1044
ROM = 28 D1 5E B6 6 0 0 93
Chip = DS18B20
Data = 1 5F 2 4B 46 7F FF 1 10 DC CRC=DC
MASHTANKTEMP 100 startTime50887 MashStartTime 51932time elapsed-1045
ROM = 28 D1 5E B6 6 0 0 93
Chip = DS18B20
Data = 1 56 2 4B 46 7F FF A 10 96 CRC=96
MASHTANKTEMP 99 startTime52228 MashStartTime 53271time elapsed-1043
ROM = 28 D1 5E B6 6 0 0 93
Chip = DS18B20
Data = 1 4E 2 4B 46 7F FF 2 10 9E CRC=9E
MASHTANKTEMP 98 startTime53567 MashStartTime 54610time elapsed-1043