I am trying to control a incubator with a LM34 and a relay. I want to be able to turn the heating element on and off when them temp gets to 0.5 of target. My current problem, as i am new to c, is getting arduino to print the LM34 temp to a serial lcd. i can get the LCd to display text, but dont even know where to start, even though it must be simple. Second problem is going to be target temp adjustment. The relay part, i think, should be the easiest. Any help would be great
Thanks
Ryan
I have some simple examples on my website for LCDs and reading a sensor.
The LCD examples use the LCD4bit library. See the apllication hints at Loading...
Also the O'Reilly "Making Things Talk" book has a number of examples.
(* jcl *)
someone used to have a kegarator controller using arduino that i bet i could adapt, but now i can not find it. from what i remember of it it would be perfect with a temp adjustment. Anybody know what happened to that project, cant seem to find it in the search. thanks
Ryan
Getting .5 degrees (C or F ?) control using an on/off relay is going to be pretty difficult. You will most likely cycle above and below the 'setpoint' temperature, overshooting and undershooting by a given amount, often in a wider range then desired.
Good temperature control frequently requires a PID control algorithm. There is good library example in the Arduino playground somewhere. Also where you place the sensor and the accuracy of the sensors also controls how tight a temperature control you will end up with. Many times multiple sensors are used and a average temp is calculated.
I assume you will be using some kind of heat lamp(s) for the heat source. Consider using a state relay instead of electromechanical relay. Often small fans are also used to insure good mixed air temperature.
As far as how to enter the desired 'setpoint' temperature in the Arduino, the simplest method would be to use a resistor pot to input a 0-5vdc voltage into a analog input pin. Your software program could then scale it and display it as well as use it for the control point for your temperature control algorithm.
Good luck
Lefty
i am not sure if this would help, but i was having some similar problems with LM 34 sensors and i am using a free program call stamp plot version 3. it takes your sensor readings from whichever port you specify and plot them for you and has a built in temperature shutoff.
Theoriginalryan-
Here is a link to the kegerator code: