Hackaday Prize Entry: A Mobile Electric Gate

Electric gates can be an excellent labor-saving device, allowing one to remain in a vehicle while the gate opens and closes by remote activation. However, it can become somewhat of a hassle juggling the various remotes and keyfobs required, so [bredman] devised an alternative solution – controlling an electric gate over the mobile network.

20 years ago, this might have been achieved by wiring a series of relays up to the ringer of a carphone. These days, it’s a little more sophisticated – a GSM/GPRS module is connected to an Arduino Nano. When an incoming call is detected, the gate is opened. After a 3 minute wait, the gate is once again closed.

[bredman] suffered some setbacks during the project, due to the vagaries of working with serial on the Arduino Nano and the reset line on the A6 GSM module. However, overall, the gate was a simple device to interface with, as like many such appliances, it has well-labelled and documented pins for sending the gate open and close signals.

[bredman] was careful to design the system to avoid unwanted operation. The system is designed to always automatically close the gate, so no matter how many times the controller is called, the gate will always end up in a closed state. Special attention was also paid to making sure the controller could gracefully handle losing connection to the mobile network. It’s choices like these that can make a project much more satisfying to use – a gate system that constantly requires attention and rebooting will likely not last long with its users.

Overall, it’s a great project that shows how accessible such projects are – with some carefully chosen modules and mastery of serial communications, it’s a cinch to put together a project to connect almost anything to the Internet or mobile networks these days.  For a different take, check out this garage door opener that logs to Google Drive.

SDR Sniffing Electric Gates

Most wireless OEM hardware traditionally use 433MHz OOK modules to exchange information. The encoding and encryption of this data stream is left as a task for the embedded software designer. In most cases, the system can be hacked using a replay attack where an RF packet is recorded and replayed to emulate a valid user. [Gilad Fride] hacked his parking gate using this technique but decided to go the extra mile of connecting it to the internet.

He used an RTL-SDR dongle and ook-decoder by [jimstudt] to sniff out the gate code and this code was tested using an Arduino. The final implementation was done around an Onion Omega which talks directly to the RF transmitter module using the fast-gpio binary. Internet connectivity was achieved using Onion Cloud API which is used to trigger the execution of code thereby sending the gate opening signal.

[Gilad Fride] uses the IFTTT Do button to provide a GUI and he demonstrates this in action using an iPhone in the video below. The project can be extended to open garage doors or turn off the lights of your room over the internet.

If you are looking to hack your home security system, look no further as SDRs have be used to communicate with wireless products effectively in the past. We are hoping manufacturers take a hint and start using better encryption.  Continue reading “SDR Sniffing Electric Gates”

ESP8266 MQTT Remote Gate Entry

Do you live in an area where you (or your car) are locked in by a gate? If so, you may know how [Alexander Else] feels about letting his guests in and out constantly with a remote control — it’s just not convenient. [Alexander] could have just purchased some extra remote controls and passed them out, but they aren’t exactly as cheap as party favors. Not to mention it wouldn’t make sense to hand one out to every single visitor anyway. Because the gate is a community gate, hacking the actual gate system was not an option. There was only one thing he could do — hack the remote control!

Like just about every other hacker, [Alexander] had a spare ESP8266-based board lying around. [Alexander] also had a couple of spare relays which he used to control the two buttons on his designated ‘sacrifice’ remote — one relay per button. After throwing these parts together with a couple of supporting bits of electronics, the hardware was done.  Now [Alexander] can just set up HTTP Request Shortcuts on each trusted visitor’s smartphone. From there on out they can open/close the gates themselves!

Originally, he was using IFTTT to trigger the string of events that make it all happen, but there was a delay of about 8 seconds (from trigger to relay action). [Alexander] was not having this so he turned to the HTTP Request Shortcuts app. When he made this change, the delay disappeared. Continue reading “ESP8266 MQTT Remote Gate Entry”