I have a 4 channel RF remote and receiver that I would like to use to remotely operate about 8 functions on my car. The receiver has momentary outputs. I am looking for ideas on a simple circuit that would control different functions by using sequential combinations of the channels. For example: maybe pressing channel 1 followed by another press of channel 1 (within a specific time), would activate a relay to lock the doors, and pressing channel 1 followed by channel 2 would activate a relay to unlock the doors. I would like the relay to remain closed for as long as the second channel is held. Then when released, it would reset the circuit to a stand-by mode. Someone suggested that this should be done with a PIC but I think that might be a bit of an over kill. My thinking is that the first channel press would activate a timer on the release of the button. The timer would then hold 1 input high on 4 AND gates. Something would have to now direct all the channels to the other 4 inputs to the AND gates and prevent them from activating there respective timers. I really don't have any experience in digital circuits to design it although I am trying to learn. Can anyone point me to a few circuits that might get me started? Your help is greatly appreciated.

 

This is called a decoder, with 4 inputs you can get 16 different outputs.

 

OK. How do you build one?

 

Here is one:

http://www.eleinmec.com/datasheets/ds_sgsthompson_4514_decoder.pdf

You can find more by searching 4-bit decoder in google.

 

I understand the 4-bit decoder but the inputs I would like to be sequential not simultaneous. Don't I need something that latches the first input until the second input is received? Also, how do I build it so the second input doesn't latch itself as it would if it was the first input? Am I missing something in the way the decoders work? Bear with me, I really am trying to do this myself but I have very little background in these types of circuits.

 

You will need a quite complicated circuit and thus it is better to use a microcontroller.