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9 years, 11 months ago.
NEED URGENT HELP, DHT 22 FREEZING BEETLES! need help for timer function, DHT22.
Hi guys
Using an LPC1768 i am programming a freezer to freeze insects in intervals of x time, and x degrees celcius.
My idea is to start at 16 degrees C
after 20 min. it should be 5-6 degrees less
stay at that temperature for 10 min.
repeat step 2 and 3 until max freeze around -10- -13 degrees C
Up for a challenge? Beer for the one who cracks it ;)
1 Answer
9 years, 11 months ago.
This is quite straight forward, but need to know about the rest of the hardware you want to use.
In a practical project for something like this you will need a display to monitor what's going on, that's no problem a 1602 type (2 line x 16 characters will do here) , user input to adjust settings by way of some key switches (again no problem a 2 key 'select' and 'set' menu type input will do), and output device to control switching on/off the freezer, relay or solid state switch. You will also need to have some idea of the freezer parameters, mainly overshoot. Refrigeration and heating systems will over shoot the required temperature if you switch off at the measured, desired temperature. So how long does it take from switch on to reduce the temperature by 1 degree c is a start. Also how 'flat' does the temperature need to be, if it needs to be within 1 or 2 degree c of the required temperature then periodic switch on will be needed to maintain this.
Once you know this and probably a few other things, then you can consider the code for the controler.