IR signal validation without MCU

Projects General Guidance
1

Greetings.

Recently I've been thinking about making an IR remote controlled wall plug for AC appliances.

One of the ultimate goals would be to try make something that is as cheap and compact as possible, and microcontrollers take money and space.

The algorithm: When the infrared sensor (TSOP34838 38khz) sends its 32bit serial data, the circuit then reads, stores this data, and checks wether it is the correct signal. If the signal is right, the circuit flicks a toggle switch, which powers a relay to power the appliance. If the signal comes in again, the circuit flicks a toggle switch again to power off the relay.

My question:
What would be the best approach to creating a circuit like this without microcontrollers? I have been thinking about shift registers, but instantly I run into the problem of how would I run the clock at same frequency as serial data. How would I create hard-memory for what the right input signal is? How would I be able to adjust this hard memory to learn a different signal?

Of course I don't expect a full answer, but something's better than nothing :slight_smile:

2

Not only the data, but also time between the pulses is important.
That would require a shipload of digital ports and a clock signal from a ceramic resonator or crystal.
Expect a circuit like that to be very complex, and several times the price of a $2 Nano clone.
Leo..

3

You can get a 3mmx3mm microcontroller with a 32bit ARM Cortex-M processor. What kind of electronic do you think you can put in that area?

Microcontrollers are now produced in technologies that are so small, that you cannot build any discrete electronics that are smaller than that.

4

I had imagined validating an IR signal could be simpler than using a microcontroller, seems that it is not.

Thank you both for your insight.