Even though the built-in antenna of the Flipper Zero isn’t too bad for capturing and replaying Sub-GHz signals, adding more range to it is pretty easy as well. This can be achieved by using an external module called “CC1101”. The CC1101 is a radio frequency (RF) transceiver designed for low-power wireless applications in the sub-1 GHz range. A CC1101 can be purchased in different stores online, and will cost you less than 10 euros.
What CC1101 should you buy?
Different types of CC1101 modules can be purchased, and the quality really differs not only between manufacturers, but also from module to module made by the same manufacturer. The only CC1101 that has a consistent track record is the one you can buy from Ebyte. This is made in China, so delivery could take a couple of weeks, but it’s definitely worth the wait.
You might be lucky with a CC1101 from another manufacturer, but using a CC1101 from another manufacturer can even shorten the range compared to the Flipper Zero internal antenna. This could be the small antenna that was part of the CC1101, or it could be the chip itself. There’s no easy way to figure out what the problem is, so it’s better to just go for a chip and manufacturer you know just works. And the price difference was minimal between the two, except for shipping costs and delivery time. But that might be different depending on where you live and order from.
Different antenna types
It is important that you use the right type of antenna for your CC1101. You need to purchase an antenna that works on the frequency you want to work on, but the length will also matter:
- The size of a 1/2-wave is one half of the wavelength of the desired frequency, and a 1/4-wave antenna is approximately one-quarter of the wavelength of the desired frequency.
- More energy will be transmitted horizontally in 1/2 wave antenna compared to 1/4 wave antenna.
- A 1/2 wave antenna will be taller in size and would therefore be able to avoid more obstacles than a 1/4 wave antenna.
The antennas I tested are a 1/2 wave whip antenna and a <1.5 wave antenna from Ebyte (TX433-JKD-20P). As you expect, it’s a trade-off between range and portability/usability. So even though the 1/2 wave whip antenna gets you more range than the smaller <1.5 wave, it’s size means it’s less portable.
How to wire the CC1101 to your Flipper Zero
The easiest way to quickly connect the CC1101 to your Flipper Zero is by using jump wires. These can be bought for a couple of euros/dollars from Amazon for example, and will allow you to connect the chip without soldering it to a board. Just make sure you have “male to female” jump wires in the set you order, because you need them to connect it to the Flipper Zero.
How you need to connect your CC1101 to the GPIO ping on your Flipper Zero, depends on the type or manufacturer you buy. The wiring schematics can bee found here, thanks to quen0n. For the CC1101 from Ebyte, it looks like this:
Testing your CC1101
Now that you connected the CC1101 to your Flipper Zero, open the Sub-GHz app. If you scroll down in the Sub-GHz menu, you will find the radio configuration. When you open it, you should see that your Flipper Zero detected an external CC1101, and it changed the antenna from internal to external:
When your Flipper Zero didn’t change the antenna type automatically, you can still change it yourself.
Now you can start testing with receiving and sending Sub-GHz signals to see how much your range extended. The built-in antenna could get you up to 50 meters (or 54 yards in freedom units), and depending on your CC1101 and the antenna you use it could be 100 meters (or 109 yards in freedom units) and more. The best way to test it, is to use a remote you already have and see if you can capture those signals:
If that works, you can start testing the range outside in real life scenarios.
Disclaimer
This post was written with Xtreme firmware version “XFW-0053_02022024” installed, so depending on when you read this things might be working different on your Flipper Zero.
This post is for informational purposes only, and we are not liable for any loss or damage resulting from its use.
Also: don’t be a skiddie, or an a-hole, and stay vigilant!
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