I wanted a garage door opener that wouldn't need to change batteries and could stay hidden, not making rattle noise while driving.
While searching for an idea, I found a capacitive sensor on ebay that could work pretty nice behind the car dash. This instructable needs basic knowledge in electronics, if you need any help feel free to ask, or you can use www.google.com.
Bill of Materials
1 - Garage door opener remote (Already programed)
2 - Capacitive sensor, that you can hide wherever you want and it has the sensitivity necessary. I had luck finding an Omron E2K-F10MC2 on ebay for $17.
3 - Perfboard or similar
4 - Eletronic components
- 1x L7812C - Positive voltage regulator
- 1x CMOS 4011 - Quad 2-input NAND gate
- 2x 1uF 50v capacitor
- 1x 10K ohm resistor (Observation at schematic)
- 1x 0.5A fuse
- Optional - 2x2 male Header Pin, 1x Jumper
- Connectors, fuse holder and wires
5 - Electrical tape and double sided tape
Step 1: Schematics
The circuit is very simple, it uses the car battery as input power (you can use the 12v line from cigarette lighter). The energy goes through a fuse just in case of something wrong, then I used a voltage regulator to hold the energy spikes from engine start (If you ignore this part you will burn the remote control).
The sensor and remote control are connected to the filtered 12v line, the signal from sensor goes by CMOS inverter, it can be cascaded depends on NO/NC sensor, the CMOS output should be able to drive almost any remote control that uses 12v battery. For a remote control that uses lower voltage, you can use an voltage drop circuit.
Step 2: The Mess Is Made - Soldering the Components
Plan the schematic on perfboard and connect everything with solder, another technique is to use "Wire wrap".
The remote that I used is very simple, it has a push button that closes with +V from the circuit, the purple line on pin 2 of the CI is the same line from the output of the switch (When pressed, the switch drops the voltage to 0v at pin 2 of the CI).
Step 3: Hooking Up Everything
I chose to instal the sensor next to the sound. Next step is to apply double tape to the sensor head and hook the wires.
Step 4: Connect to the 12v and Isolate the Electrical Parts
It's good to use duct tape on everything to avoid noises and short circuit.
Better to do this step with the key off, you could easily burn a fuse here.
Step 5: Test Time!
Video of the hidden remote control working.
I hope you enjoy the instructable and feel free to comment or ask questions!