How does freETarget work?

freETarget has four microphones placed just behind the target. Located at the 2, 4, 8, 10 oclock positions, they listen for the sound of the target paper tears. As the projectile goes past a counter is started, and using the time difference between the microphones the firmware figures out the location of the hit.

The projectile location is transmitted to a PC which puts the score on the display and keeps track of your score.

What are the design goals?

We wanted freETarget to be accessible to a wide variety of users regardless of where they live in the world.

  • Low cost parts
  • No export barriers on components
  • Limited technical expertise
  • Use indoors or out
  • Easy to assemble on site
  • Support both pistol and rifle use

Putting all of this together, freETarget uses a PC laptop as the display device, and connects to the acquisition hardware using a long USB cable.

What targets will it support?

freETarget supports all of the ISSF targets up to 300 meters. Additional national targets are supported. New targets can be added as needed.

Users have shot the targets at ranges from six meter all the way up to 100 meters.

Some work is being done for F-Class at 1000 meters, but the results are not yet in.

How accurate is freETarget?

The accuracy is a function of how precisely assembled the target holder is. Another source of accuracy is the management of the witness paper. With a bit of care, the average error is in the order of 0.2mm per shot or about 0.1 points on an air rifle target

How do I make FreETarget?

There are three ways you can build freETarget

  • Visit Github.com/ten-point-nine/freETarget for the complete design files
  • Buy the circuit and assemble it into your own target housing
  • Buy one of the complete kits and assemble it yourself

Can I buy the circuit?

Yes, the circuit is available for purchase at $200 US plus postage. Visit the Store page to setup purchase and shipping. https://free-e-target.com/store

Can I get 3D printed parts?

Yes, many of the builders have made 3D printed parts available. Look up the 3D parts from the Building freETarget > Community Made Parts. https://free-e-target.com/community-made-piece-parts/

Will you take it back if I can’t get it to work?


freETarget is a community based open source project that relies on the user’s to make it work. This is not a commercial product that you can call customer support for. Ask somebody in your club for technical help, there’s bound to be a computer nerd who can help.