Arduino code and EAGLE schematics file for an ammo counter for NERF blasters.
- lets you choose between pre-defined mag sizes (12, 30, 6)
- counts down the available darts in the magazine
- resets counter on a reload (magazine change)
Developed for and tested with an Arduino Pro Mini (without header pins) or a clone thereof.
- 5V Arduino Pro Mini (or a clone) with FTDI programmer
- 0.96-inch SSD1306-compatible I2C OLED display
- some small-diameter wire (e.g. 0.14mm²)
- 3 10 kOhm resistors
- 3 push-button switches
- 1 toggle switch (optional)
Image: schematics
EAGLE schematics file: nerf_ammo_counter.sch
The installation is completely up to you and depends on the actual blaster of your choice.
Basics steps:
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Connect the RAW and GND directly to the battery circuit of your blaster
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Place and wire the push-button switches according to their function:
"firing" button has to be pressed when the trigger is depressed all the way
"reload" button has to be depressed when a magazine is taken out of the blaster
"select" button can be placed anywhere you're comfortable with -
Mount the OLED display onto your blaster and wire it (e.g. cut a hole into the shell)
Use a blaster with a decent amount of space, like a Stryfe, Rapidstrike or Hyperfire.
If enough space is available, use a piece of perfboard to share connections to ground and mains.
This project assumes that you have already modded the blaster to use a LiPo Battery (7.4V and 11.1V are both fine). The normal Mignon batteries are to weak to power both the flywheels and the Arduino reliably.