Remote wall switch with lithium button cell

The lack of security of these devices is very comical. Because there is none. You can receive and send these codes with a little bit of software and a USB 433 radio. Every button press in range can be recorded and replayed. Which allows you to have fun with you neighbors lights.

Bas

This may do the trick. https://www.ebay.com/itm/433Mhz-Wireless-RF-4-Channel-Output-Receiver-Modules-and-Transmitter-EV1527-Cof8/393253000789

Jeremy Impson

I'd like to use one of these (actually, one of the battery-less designs) as a digital input to an arduino or raspberry pi controller (for example to control strings of addressable RGB LEDs or to allow concurrent control of an outlet power from both a smart phone and a wall switch). The trouble is the receiving unit's circuit board runs on AC. I've added bodge wires to one so that I can sense the state of the LED, but connecting that to a microcontroller will also connect it to earth ground, defeating the value of its isolated power supply. Before I go at one with a heavy hand to convert it for DC use, have you seen just the DC component of one of the receiver units? Preferably not just the RF receiver, but also the microcontroller that stores and interprets the code signals.

Jeremy Impson

Nono please DO!!

Michael Thompson

I like these little transmitters, good video Clive. L1 is to provide power to the RF amplifier and its value is selected to prevent the RF energy from flowing back up into the power supply.

The pads are part of the matching network. There's extras so that they have flexibility matching the output impedance of the RF chip to the impedance of the antenna. You never know what the actual as manufactured impedance of the antenna will be with the enclosure and other compoenents/board layout. that's my guess at least... :)

Great, worked now. Thanks a lot

Peter Stimpel

I'll try again.... I'm sure I put a link in last time:- https://www.ebay.co.uk/itm/284196262328

Big Clive

Please don't tempt Clive to print something pink and NSFW just to remotely control a light bulb. :-) :-)

Jon Knight

This was the listing for the switch plate. If you search for 433mhz receiver you will find a wide variety of them. They mostly recognise all common code formats. Note that there are versions with easier battery replacement via a drawer. I've got one on order.

Big Clive

Zero RF knowledge here but those extra capacitor points make me wonder what kind of wave form the chip is putting out - would they be for getting rid of harmonics?

Raven Luni

Have you considered designing a 3D printed box and switch tops that is saner? You could also have fun making it not look like a switch.

Mike Bird

Anything that uses those 12v batteries is best avoided, like companies that constantly putting in AAA instead of AA on things that don't warrant it (weight/size) but would benefit greatly from the extra capacity. Ditto with Michael, I dig PCB trace RF design.

Anton

Wonderful! I love radio and these counts! RF rocks! I love seeing the antennas they come up with. (PCB antennas are of interest.) The unused RF antenna tuning circuit is a classic one! Pi-Network I have built them myself on a larger scale for ham radio! Great stuff man thank you!

Michael Thompson

Clive, if you don't mind could you link to the switch and the relay, please?

Peter Stimpel

Interested I am