Heating Automation Code and Brew Day Test (7/4/16)

In order to automate the heating during the brew, I modified the existing code for the temperature probe, which I got from an Arduino example (see my post about the temperature probe). Basically, I kept the temperature probe functionality and just added in some conditions for the stages of my next brew, which is a mandarina pale ale.

Automated so far:

• Heating up to 150-165 F
• Maintaining heat in that range for 20 minutes while grains steep
• Bringing to a boil
• Alerts for adding ingredients at certain time points during the boil

However, the alerts only pop up on the serial monitor on my laptop, so I am hoping to buy an LCD screen and piezo buzzer to make noise and display the next step. 

With the code finished, today was brew day!

The ingredients.

The setup.

Boiling wort.

Post-brew ice bath.

The wort is now fermenting, and this time the recipe calls for a two-stage fermentation process, so I will be moving it to a secondary fermenter after 4-6 days.

UPDATE 7/9/16: Here is the code I used, which has now been tested during this run as well as another time to fix a few bugs, and seems to run perfectly now (note: I also bought a piezo buzzer to alert us when the next ingredient should be added and put that in the code):

#include <Time.h> #include <TimeLib.h> #include <OneWire.h> // Adapted from "OneWire DS18S20, DS18B20, DS1822 Temperature Example" by Sonia Holar and Christian Volz - July 2016 // Procedure for Mandarina Pale Ale // // http://www.pjrc.com/teensy/td_libs_OneWire.hTimel // // The DallasTemperature library can do all this work for you! // http://milesburton.com/Dallas_Temperature_Control_Library OneWire ds(2); // probe on pin 2 #define RELAY_PIN 10 //relay pin 10 const int buzzerPin = 9; //piezo buzzer on pin 9 int x = 0; int y = 0; int SteepStart = 50000; int Stage1 = 1; int Stage2 = 0; int reachBoil = 0; int boilStart = 50000; //my added variables void setup(void) { pinMode(RELAY_PIN, OUTPUT); pinMode(buzzerPin, OUTPUT); Serial.begin(9600); tone(buzzerPin,1000,1000); //beep once on startup } void loop(void) { byte i; byte present = 0; byte type_s; byte data[12]; byte addr[8]; float celsius, fahrenheit; if ( !ds.search(addr)) { Serial.println("No more addresses."); 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 unsigned int 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); if (cfg == 0x00) raw = raw << 3; // 9 bit resolution, 93.75 ms else if (cfg == 0x20) raw = raw << 2; // 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; Serial.print(" Temperature = "); Serial.print(celsius); Serial.print(" Celsius, "); Serial.print(fahrenheit); Serial.println(" Fahrenheit"); //MY CODE: if (Stage1 == 1) { //stage1 = heating up and then steeping grains Serial.println(x); Serial.println(y); Serial.println(Stage1); Serial.println(Stage2); Serial.println(now()); //just for our information/to make sure everything works properly if (fahrenheit >= 160){ digitalWrite(RELAY_PIN, LOW); //turn off heat Serial.println("Relay off"); if (x==0){ x=1; } } else if (fahrenheit <= 155){ digitalWrite(RELAY_PIN, HIGH); //turn on heat Serial.println("Relay on stage 1"); } } if (y!=x){ SteepStart = now(); tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) Serial.print("NEW SteepStart: "); Serial.println(SteepStart); y=x; Serial.println("Add grains");//alert us to add grains } if (now() >= (SteepStart+1200) && now() < (SteepStart+1210)){ //at 20 min mark Stage1 = 0; Stage2 = 1; tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) Serial.println("Remove grains");//alert us to remove grains } if (Stage2 == 1){ //stage2 = bring to boil and maintain 60 mins digitalWrite(RELAY_PIN, HIGH); //heat on Serial.println(x); Serial.println(y); Serial.println(Stage1); Serial.println(Stage2); Serial.println(now()); Serial.println("Relay on stage 2"); if (fahrenheit >= 205) if (reachBoil == 0){ tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) reachBoil = 1; boilStart = now(); Serial.print("boilStart set to "); Serial.println(boilStart); Serial.println("Add DME and first hops"); //alert us to add DME } } if (now() >= (boilStart+2700) && now() <= (boilStart+2710)){ tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) Serial.println("45 min have passed, add next hops");//alert us 45 min mark } if (now() >= (boilStart+3300) && now() <= (boilStart+3310)){ tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) Serial.println("10 min have passed, add next hops");//alert us 10 min mark } if (now() >= (boilStart+3600) && now() <= (boilStart+3610)){ digitalWrite(RELAY_PIN, LOW);//heat off tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) Serial.println("5 min passed, Relay off"); //alert us 5 min mark Stage2 = 0; //end stage 2 } //add alert for 70F in ice bath //Heat to 150-165F, maintain for 20 mins (steeping) //Bring to boil (212F) - add DME, then first hops //Maintain boil 45 min, add hops; 10 min, add hops; 5 min, turn off heat //Ice bath - want T to fall to 70F }

UPDATE 8/10/16: I forgot until now that I added a part to the code that turns the heater off during the boiling stage and back on below a certain temperature, instead of having the heater on the full 60 minutes of boiling - this allows for less loss of liquid, which means more wort to turn in to beer at the end! Instead of turning the heat on in stage 2, I inserted the following:

if (Stage2 == 1){ //stage2 = bring to boil and maintain 60 mins if (fahrenheit <= 203){ digitalWrite(RELAY_PIN, HIGH); //heat on Serial.println("Relay on stage 2"); } else if (fahrenheit >= 205){ digitalWrite(RELAY_PIN, LOW); //heat off - want to prevent losing too much water by just leaving heat on during all of boil if (reachBoil == 0){ tone(buzzerPin, 1000, 1000); //(pin,frequency,duration in ms) reachBoil = 1; boilStart = now(); Serial.print("boilStart set to "); Serial.println(boilStart); Serial.println("Add DME and first hops"); //alert us to add DME } }

I chose the temperature cutoffs of 203 and 205 from observing the brewing process with this heater. Generally, it would not go far above 205 F once it started boiling, and would completely stop bubbling around 203 F.