Week of the 01/23/2023 - #04

Contents

tech

• Hacking garage remote controls

Hacking garage remote controls

I wanted to understand how the garage door openers worked. I want to be able to have severals different garage openers in a single remote and wanted to understand how they worked. It’s pretty straight forward. Here is the summary:

• Most remote controls use a 433 MHz carrier signal
• The controls basically have a number stored in them
• You can program the opener to “learn” the code of the opener by putting it in ‘program mode’ and then sending it the signal of the key control
• There are ‘universal copiers’ that can be used to copy the code from control to control.
• These usually have 4 ‘slots’ where you can store the codes / patterns of other controls.
• You set them into program mode by holding the A and B keys together and then while holding A press B three times. See this YouTube Video
• In all examples I saw you seem to need to reset the device to copy the codes. I’m still not sure how you can save one pattern to A and later save a different one to B. Need to see how this worked.
• The universal control I opened has a PIC12F629 microcontroller and an R433M Saw 433.92MHz resonator.
• Here are the pics:

• This guys shows how you can build a transmitter and receiver
• This is another home-made project - “A 433 Mhz garage door opener was build using a PIC microcontroller. The 433Mhz signal from a garage door opener was received on a 433 Mhz receiver module for data ($3) and connected directly to the sound card of my PC. The signal was analyzed using audio editing software. On the basis of the timings of this signal a microcontroller program was written that similarly replays the signal on a 433Mhz transmitter for data ($3).”