Ledmasters has created a chronograph for measuring bullet speed, using a Teensy 4.0 connected to an Adafruit Feather M0 via RFM69 433MHz radio modules.
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Stats are displayed on a 3.2″ TFT display, and can be printed via an integrated thermal printer. Piezos attached to PET film are used to measure the bullet strike and elapsed time over a 12″ span. More information about the project can be found in the original forum thread.
![](/wp-content/uploads/2024/03/bullet-2-770x1024.png)