BBQ Temp Controller Build
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I'm in the process of building a BBQ temp controller, and was trying to figure out the best way to remotely monitor/control it. After coming across this website a month or so ago, I'm now running OpenHAB on a RPi2 and have a couple temp sensors deployed around my house.
This project is a little more involved, and I'm sure I'm going to run into roadblocks along the way. My goal is to have a sitemap in OpenHAB that will allow me to set and monitor my desired grill temp, which will control a small fan on my BBQ using a PID algorithm, as well as display the temps of the meat probes so I can know how things are going.
I currently have the sitemap setup in OpenHAB, and have had the code working for the thermocouple temp probes that I will be using for the grill and meat temps. Today I will start trying to get the two to work together, based on the MySensors Serial API. I'll be using the NRF24L01+ radio modules for this. I'll post my code periodically, and hopefully will have some chime in on how to make it work or improve it.
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Below is a very rough sketch of what I have so far. This is not working or tested even yet, but it does compile in Arduino IDE. I will breadboard the sensors I have in the next couple of days and get the basics working, then I will have to figure out how to send the temperatures over to my gateway. Next will be configuring for receiving commands from the gateway/controller to allow me to set my target temperature on the Arduino. Any recommendations are welcomed.
This program is my attempt at creating a BBQ controller for my Big Green Egg using an arduino to monitor grill and meat temps as well as control a fan to regulate the grill temperature. Components used: - Arduino UNO - 10CFM Brushless DC Blower - Level Shifter - K-type Thermocouple - K-type Grill Probe - K-type Meat Probe Pin assignments: */ /* Tasks: - Selftest - Fan 0-100-0 - Check for Probes - Set Grill Temp - Setup Display - Grill Temp - Probe 1 - Probe 2 - Fan Status - Elapsed Time - Measure Temperature - Grill - Probe 1 - Probe 2 - Analyze Temperature - PID Contol - Control Fan - PWM Value - On/Off */ //-------------------------------- Classes ------------------------ //-------------------------------- Includes ----------------------- #include <MySensor.h> #include <OneWire.h> #include <DallasTemperature.h> #include <SPI.h> #include <PID_v1.h> //-------------------------------- Defines ------------------------ #define oneWirePin 9 #define TempPrecision 9 #define MAX_ATTACHED_DS18B20 16 OneWire oneWire(oneWirePin); //Setup oneWire instance to communiate with any oneWire devices DallasTemperature sensors(&oneWire); //Pass our oneWire referenceto Dallas Temperature. DeviceAddress Probe0, Probe1, Probe2, Probe3; //Define arrays to hold device addresses. MySensor gw; unsigned long SLEEP_TIME = 15000; float lastTemperature[MAX_ATTACHED_DS18B20]; int numSensors = 3; boolean receivedConfig = false; boolean metric = true; MyMessage msg(0,V_TEMP); void sketchInfo () { gw.begin(); gw.sendSketchInfo("Temperature Sensor","1.0"); } void setupProbes () { sensors.begin(); sensors.getAddress(Probe0, 0); sensors.getAddress(Probe1, 1); sensors.setResolution(Probe0, TempPrecision); sensors.setResolution(Probe1, TempPrecision); } // Cycle fan from 0-100-0% power over 10 seconds. void selftestFan () { } // Verify which probes are connected and report status for 10 seconds void selftestProbes () { } void printTemperature(DeviceAddress deviceAddress) { float tempC = sensors.getTempC(deviceAddress); //Display Temp in °C //Serial.print("Temp C: "); //Serial.print(tempC); //Display Temp in °F Serial.print(DallasTemperature::toFahrenheit(tempC)); Serial.print(" F "); } void printData(DeviceAddress deviceAddress) { //Serial.print("Device Address: "); //printAddress(deviceAddress); //Serial.print(" "); printTemperature(deviceAddress); //Serial.println(); } void sendTemps () { for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) { float temperature = static_cast<float>(static_cast<int>((gw.getConfig().isMetric?sensors.getTempCByIndex(i):sensors.getTempFByIndex(i)) * 10.)) /10.; gw.send(msg.setSensor(i).set(temperature,1)); lastTemperature[i]=temperature; } gw.sleep(SLEEP_TIME); } void setup() { Serial.begin(9600); sketchInfo(); setupProbes(); //selftestFan(); //selftestLCD(); } void loop() { // put your main code here, to run repeatedly: gw.process(); sensors.requestTemperatures(); printTemperature(Probe1); printTemperature(Probe2); sendTemps(); //readTemps(Probe0); //readTemps(Probe1); }
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Cool project! Following.
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I've been watching this one, but will watch this one evolve too.
Waiting to see if they get a web app done.
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@BulldogLowell
That looks like an interesting project as well. This originally started very similar to that one, and I was planning on using a local LCD on it for the display. I quickly realized that the local LCD would not give me the "warm fuzzy" that checking this remotely would give me. When I started going towards a web interface design, I then realized that I really didn't need the local LCD at all.I'm not at all good with the programming piece, but I've gotten by so far. We'll see how this works out.
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@Tango2 Check this link, it is something I built for my Big Green Egg BBQ.
It looks like it could be my sensors material.
http://www.susanminor.org/forums/showthread.php?315-PID-Controller
Maybe this may help.
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@5546dug That's an interesting build. I've come across several using a PID controller similar to that, however they have mostly been on electric smokers. My original intent was to do a PWM fan that could be speed controlled, but it was very hard (impossible) for me to find a blower type fan that was PWM-capable. My very initial testing showed that an on/off model would work as well but I haven't tried this on the Big Green Egg yet.
My main concern is being able to feed a temp from my phone back to the arduino controlling this, and being reliable if for some reason wireless connectivity was lost from the arduino. I don't think this should be too hard, but will probably take some trial and error on my part.
