How to make a Door Control Unit

Post by **Neo** » Sat Nov 28, 2009 5:25 am

Door Controlling includes roller doors and shutters. The reason I had to build my own door controlling system was that people who fix the roller door requested $300 to replace the unit which was burned due to lightning. Mine is a 12V DC operated motor and control unit that includes a remote control and battery pack.

I spend a few days on studying the 3 wires going from control unit to motor which is integrated inside the roller door. There are two mechanical sensors which touches on top and bottom position of the door. The sensors provide feedback through the same three wires we used to provide power. If you need a detailed explanation on the combination, please request that on the same forum. (But this can be different in you).

I based my system on a Microchip PIC16F877 microcontroller. I used FETs to drive two mechanical relays and transistors to read the feedback on the position. Used micro switches for the 3 buttons, LM338 for battery charging, 5 Volts regulator for the Microcontroller and a few resistors and condensers. If you want to know the wiring, I can provide that by request. The main issues I had to come up according to my memory was to drain the FETs with a resistor and to avoid restarting microcontroller due to mechanical relays.

Fortunately, the radio reception unit wasn't damaged so I was able to connect the unit to my circuit. There were two main buttons UP/DOWN and LOCK on the remote. However if you have to build this one as well, I recommend you to buy the recption unit and the few remote controls from a auto security shop. Those can be easily integrated to the microcontroller.

Finally the source code was written using C and used a PIC programmer built by us with a series of free software to burn it on the flash. If you want a cheep PIC programmer, we can provide a very stable one for a cheep price. I'm also willing to provide the source code by request.

I spent only about $20 for the whole thing with some interesting effort and ultimately a great satisfaction when it is working for real. I must mention the name of Magneto as he has given me a great backing on it (he is a professional electronics engineer who maintains the embedded and mechatronics section of this forum).

If you are going to build your own door control system, we may be able to share our knowledge and experience with you. Please note that, discuss anything related to door control only through this topic.

Tks.