Over on YouTube CiferTech has uploaded a video showing how to create a low cost 315 MHz jammer using an Arduino and a cheap 315 MHz transmitter circuit. The 315 MHz band is used in some countries by short range wireless devices such as garage door openers, tire pressure sensors, hone security systems and car keyfobs. Some wireless home security systems have been shown to be vulnerable to jamming, as jamming can stop an alarm activation signal being received by the base unit. 

We want to note that building a jammer in most countries is completely illegal and the use of a jammer can result in severe penalties such as jail time.

On a related note, we also wanted to point out this recent tweet by Naomi Wu (@realsexycyborg), a popular Technology YouTuber who is based in China. Her tweet pointed out that some local market scammers in China use rigged weighing scales which can force the scale to display an artificially high value by using a wireless handheld remote. To combat this handheld jammers are sold so that shoppers can prevent the scammer's remote control from communicating with the scale. Although jamming is still most likely illegal in China, this could be considered an ethical use of a jammer.

Guess the product being demonstrated (If you're Chinese, don't tell them😉) pic.twitter.com/TWHYwmUHYg

— Naomi Wu 机械妖姬 (@RealSexyCyborg) March 8, 2023

.@c0un7z3r0 for it first- there are companies that rig popular brands of scales so they can be adjusted with a small remote control. The store sells jammers to use against the remote used by those rigged scales. pic.twitter.com/juHeLLobnD

— Naomi Wu 机械妖姬 (@RealSexyCyborg) March 8, 2023