Ammo Counter Mk3 – Collaboration with

I have partnered with Nathaniel of to develop the ultimate ammo counter solution.  The circuit is a derivative of my MK3 design.  I am calling it MK3 SMD.  The new circuit is exactly as tiny as my MK3, but has modifications to allow the outsourcing of manufacturing.    In addition, with Nathan’s feedback I was able to put the finishing touches on some never before seen software features.  This is so awesome!

Here is an official announcement from  Nathan will be selling the MK3 SMD with my firmware, along with some fantastic accessories this year.  Check it out ~!

The previous feature set of the MK3 was the ability to have 10 programmable clip slots.  Two buttons below the display are used to change clip slots.  Holding the button accesses a menu where you can modify the size of the clip in memory.  This was a huge feature for me.  Allowing me to assemble a batch of ammo counters and ship them fast.  My designs prior to MK3 required me to wait to assemble the ammo counter until after a customer had purchased, so I could hardcode the clip sizes on the chip.  No longer.  The MK3 Ammo Counter can be assembled in large batches, pre-programmed with a default set of clip sizes.  Then the customer can change the clip sizes to whatever they want.  No special programming hardware required.  Just press the buttons to access the menu!

I have been working hard since announcing the MK3 Ammo Counter and am now ready to unveil the next revision of firmware improvements.  The setup menu system has been completely rewritten, the code structures made lean, and the display driver now supports dimming, and more!!  The menu system is super simple to access.

  • Faster selection of Clip Slots You can now select the next or previous slot instead of cycling through all slots.  The front buttons are used for both resetting the displayed count and changing the clip slot.
  • Same great selection of Fire Modes  Count Down, Count Up, Burst Fire.  From Nerf, to Paintball, to a Prop weapon build, this counter will do it all.
  • Display Brightness  is adjustable!  I never received a complaint that my Ammo Counters were too dim.  The opposite actually.  Especially indoors, the white displays I used were too bright!  Well, I kept the same super bright white displays.  Instead adding built-in dimming feature to the firmware to allow you to select how bright you want the display to be.  Works fantastic!
  • Low Ammo Flashing When enabled, the display will blink when a low ammo count is reached. Using the menu, low ammo flashing can be set to OFF or 1-9 ammo remaining.
  • Auto-Reset When enabled, the counter will auto reset a few seconds after reaching zero ammo. You no longer have to press an extra button while changing clips! If you like the button or like the counter reset synced to when you remove your clip, you can easily disable the auto-reset. Using the menu, auto-reset can be set to OFF or 1-9 seconds.
  • Compatible with Multiple Light Break Sensors. Using the menu, the fire input can be changed between Active High or Active Low input.  Allowing compatibility with any sensor with a TTL friendly voltage output.  My personal favorite is the OPB100Z as a complete sensor solution.  However, I have also heard reports of success using Adafruit’s IR Break Beam Sensor.  Nathan will be selling his own Light Break Sensor kit.
  • Faster Scan Rates  This is a no brainer feature, but the new scan rates allow for faster detection speeds for the IR Sensors.  The scan rate is so fast now, that detecting fast paintballs is no problem at all.

Lastly, I will be selling my owm MK3 kits on Etsy for a limited time, check it out~!