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Question

I'm looking to build a custom circuit for my living room The circuit I want is to control a sliding panel via a remote control

-- Thus I would have two sensors (SW1/SW2), to detect when the panel is completely open or shut, a bi-directional motor (M) to move the pannel, an infra red reciever, which could key off of at least two seperate signals, and a manual button. The behaviour would be as follows:

if IrSignal1, then set State(dir)=0 if IrSignal2, then set State(dir)=1 if State(dir)=0 && SW1=1, spin motor forwards if State(dir)=1 && SW2=1, spin motor backwards if button released (key off edge), then set State(dir)=not State(dir) (potential safety feature): if motor has been spinning for more than

10s, disengage motor.

Now, here's my big delema -- I've never done any circuit design before! So my first question is, where would I start? Where would I learn how to build the above circuit? I'm pretty good with mechanics, and can solder wires. I also know to put the above in a metal box in case of overheating. If required, I can even do embedded programming (but I'm thinking the above shouldn't require a processor right?).

If anyone can point me to a place to start, I'd really appreciate it.

Thanks, John

(Another solution is to get someone to build it for me, but I have no clue who, or how much something like this would cost. And I really don't mind learning...).

Hal Murray · Accepted Answer

It's probably simpler to do it in software. I was going to suggest that even before I got the the part where you said you could do it that way.

You can get single chip CPUs. PIC and AVR are popular. Some people prefer 8501 and/or 68xx. Use whatever you like best.

The software can be pretty simple. You don't need any interrups.

You need a power supply. I suggest a wall wart.

Inputs from the switches are a resistor from power to switch, with the other side of the switch grounded. The R-SW junction goes to an input pin. You have to debounce it in software.

The IR input is a bit tricky. You can get magic do-everything receiver modules for use with things like TV remotes. The output will be a series of pulses. It's not RS-232 but a messier encoding. There are a handful of "standards" to pick from. There are several carrier frequencies in use. You need to get a receiver module that matches the remote you are going to use.

For controlling the motor, I'd probably use a solid state relay.

Joerg · Answer

Be careful with this stuff. Mind little kids, cats, and others being on the track who could get hurt when the door closes.-- Regards, Joerg

Dave · Answer

You could monitor the motor current and when it starts to rise this can indicate that either the panel has reached fully open or fully closed or that someone/something is in the way and cut the motor.

bg · Answer

switches, current limits and optics for safety. All you would have to do isrepackage it as you see fit, and do the mechanical  mightalso be something off the shelf in an X10 product.bg

Robert · Answer

You can look up "State Machines" and implement it with discrete electronics or a simple programmable logic device or you can use a small microcontroller and do it that way.

Have you seen this site for products and tutorials?

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Robert H.

Jim Thompson · Answer

Or buy it ready-made for drapes/vertical-blinds ?:-)                                        ...Jim Thompson-- |  James E.Thompson, P.E.                           |    mens     ||  Analog Innovations, Inc.                         |     et      ||  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    ||  Phoenix, Arizona            Voice:(480)460-2350  |             ||  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  ||                  |    1962     |                      America: Land of the Free, Because of the Brave

ehsjr · Answer

Simplify it a bit - use only 1 signal. The function you want to initiate is either open or close, and in both cases you want to go to the switch limit, then turn off. So, let the limit switches control direction - no need for two different signals. Add "tie-breaker" logic so that, when powering up after the thing has forgotten where it is due to power failure in the middle of a cycle where neither limit switch is operated, it will assume that it must close (or open - you decide).

I do the open-close thing you describe with 2 relays and the two limit switches you mention.

Ed

Rich Grise · Answer

Cheers!Rich

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