Hey i need to control a heater using time I calculated according to feedback from a thermistor. i already have the equations and codes for the thermistor and to calculate the time. what I would like to know is there anyway i can use the time i calculated to to turn the heater on for that period? any help will do.
Check out the arduino blinkwithoutdelay sketch. It shows a simple example of how you can use the millis() function to keep track of passing time and make decision on when to perform tasks in your sketch.
Another method is to add a real time clock module to your board (around $15-20) and then you have complete time/date/year information at your access.
hey thanks lefty, i'm using a rely to control my heater, i found this configuration but it does not seem to work http://www.arduino.cc/playground/uploads/Main/relays.pdf i figure its mostly with my code though. do i use digitalwrite to send the signal to the relay?