Step 1: What Do You Need?
-GSM activated relay. This device will contain a SIM chip that can connect to the GSM cell phone network. It's relays must be able to be activated by phone call or text message. In my first build I used a GSM-AUTO, but found a cheaper alternative on eBay HERE for the Quad Band version (North America) or HERE for the Dual Band (Europe, Asia, etc.). it costs around $150 which has 7 relays. Another alternative is Relay Supply or you can go directly to the 7 switch device HERE. One relay is controlled by phone call and the rest are activated by text message. The relays can be set as either momentary or latched.
-Car Starter Key Fob (the remote control thing on your keychain).
-12V DC cigarette power cord
-Small plastic bag or ESD bag.
-A few wires.
-A few screw drivers
Step 2: Canabalize the Key Fob
You will have to sync your remote with your car starter. As all car starters and car starter installations are different, I won't go into detail on how to do this. Whoever installed your car starter can usually do it for a fee but I strongly recommend you google for the models manual as its a rather simple process. It usually involves either depressing the hood pin in a particular fashion (a pin that detects if your hood is popped), or pressing a button on the side of the remote starters brain under your dash.
Now remove any screws from the case and pry it apart. The circuit inside and battery are not secured in any way and came out easily.
Step 3: Solder the Contacts
The contact in the center of this picture is already powered. When a user pushes the button, the connection is made between the interlocking contacts (they look like interlocking letter E's) and the starter signal is sent. We will be soldering one wire to each corner of the contact. This takes a great deal of precision to ensure that you do not join the two contacts.
Step 4: Solder the Power Wires
Step 5: Connect Power Cable to GSM Device
I would recommend wiring the power cables into the device first. Take the 12V DC cigarette power cord and strip the ends of the cables and slide the cable through one of the ports on the side of the device. These ports can be tightened to ensure the device is weather proof. I fed the wire through the port closest to the power connector, but if your wires are higher gauge this can be difficult. Consider running the wire through the far port. The remote key fob will remain inside the device and its wires will not be run through on of the ports.
GND (ground) is clearly marked as the top most connector. Wrap the negative (black) wire from your remote key fob around the negative cigarette power connector wire and feed it into the GND connector. Screw it down tightly to ensure a solid connection.
Wrap the positive (red) wire from your remote key fob around the positive cigarette power connector wire and insert it into the +12V connector on the GSM device. Screw it down tightly and test both wires for looseness.
Step 6: Connect Key Fob Start Button Wires to GSM Device
Once this is done, consider sliding a small plastic bag or ESD bag over the remote key fob to prevent any shorts.
Step 7: Insert SIM Chip & Power Up!
The GSM device has 3 LED's on it:
-One for network connectivity. This LED won't turn on for the first 10 seconds, and then will blink quite fast when the device initializes. The rapid blinking means its searching for a network to connect to. Once it establishes a connection (this will only occur if the SIM chip is a valid one and the device is in GSM range), the light will blink much slower, indicating that the connection has been made.
-One for indicating power status (blinks regularly to indicate it is powered).
-One for indicating TX or RX. Whenever the device receives or sends a text message/phone call, this light will flash.
Connect the device to your vehicles cigarette lighter! The power LED should be flashing, as should the network LED. Once the device achieves network connectivity, the flashing of the network LED should slow down.
Step 8: Program the GSM Device
PWD is the password (which can be changed), and WHL01 is the first position in the white list. If you wanted to add a second number you would use WHL02, etc. and so forth.
The phone number to be entered should contain the area code and regular phone number with no dashes. Occasionally the international country code must be prepended to the start of the number, but try without this first.
Call the device and the first relay should loudly clack open and closed for 300 milliseconds (default length of time). The device will never pick up the phone call; rather it merely checks whether that phone number is in its white list, and then either ignores it or acknowledges it. It usually activates itself on the second ring and causes you to hear two rings to occur quickly one after another when it activates.
To update the length of time to one second, use this command:
Figure out how long you normally have to press the start button for to start your vehicle and then program the relay to open for the proper amount of time.