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 allows the outputs to be either latched or momentary. I would like 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. It could also be a press followed by a press and hold for a certain period of time. My funds are pretty limited so I can't spend a lot. Thanks for the help.