ammunition Counter for LARP Guns

No, no stronger spring, or stronger batteries, but a small electronic gadget. The Mod is built into a purely mechanical NERF sniper rifle. The remaining ammunition is displayed and a LED flash is triggered when the foam cartridge is shot through the barrel. This was done with Great Cow Basic. A compiler that eats Basic and assembles assembler for PIC and AVR. I have already written an article about Great Cow Basic and announced a report on a project realized with it. Well, here comes the report.

The Display used has very small Dimensions  128x32 pixel  (search term I2C SDD1306 0.91 128x32 OLED)

The display is only about 2.31 cm in size, the complete display has about 3.5cm, so it is ideal for installation in the target telescope.

 

FUNCTIONAL DESCRIPTION OF THE SOFTWARE:

The pictures are from an early prototype, the quality of the pictures I apologize.

POWER ON SCREEN

After the initialization, a welcome screen is displayed showing the current voltage of the Li Ion battery used. The basis of the calculation is the operating voltage of 5 V, which is kept constant. Depending on the battery voltage, a different text may be output. Please note.

You can now simply wait until the main display changes, or press the UP key to jump directly to the main display.

 

 

 

MAIN SCREEN

The main display shows in large digits the number of remaining ammunition. To the right is the level indicator for the battery power supply. If the voltage drops below the threshold of approx. 3V, the word "UP-DOWN-> Setup" will change to "charge!". The function is still available for a while, but the battery should be charged soon. If the voltage of the battery drops below 2.5 V, the display changes to "Alert!". Now the system must be switched off and the battery charged, otherwise the battery will be damaged. In the source code, the threshold Values can be individually adjusted so that you can use batteries, or a different type of battery, and still have some capacity.  If the remaining ammunition is only 3 cartridges or less, the number will flash and the display will pulsate in brightness.

FLASHTIME SCREEN

Pressing both buttons at the same time causes the setting menu to appear. The flash timer can be set here, meaning the duration of a light flash. While this setting menu is shown, the trigger can still be actuated, so you are not defenseless! The longer bars from left to right will display the remaining time until the menu is automatically exited.

 

 

ROUNDSCREEN

Press the UP and DOWN buttons simultaneously to enter the ammunition setup menu

Here you can set the number of cartridges which are loaded as "full" when changing the magazine. The longer bars from left to right will display the remaining time until the menu is automatically exited. If you press UP and DOWN simultaneously, the set ammo is stored permanently.

 

 

 

 

Before the modification is complete, let's take a look at the prototype. About the flash LED is a little shrink tube, because the flash during the development can be quite annoying. Incidentally, the display shown is not the 128x32 pixel mentioned in the article, but the big brother with 128x64 pixels. The software I have equipped with an option to use the large display as a replacement without rebuilding the display. Unfortunately, towards the end of the development, the small display broke. The Prototype has only a power supply through a USB cable (blue) the StepUp facial expressions and battery voltage monitoring is only faked here by a potentiometer. This makes sense if you want to test the thresholds of battery monitoring.

Some Pics and  a Video from the real Thing are to come shortly.

Circuit diagram, layout and software will be published under GPL 2.0.

 

 

 

Here is photo taken during a functional test.

Just before screwing together you want to know if everything still works.

 

 

 

 

Just finished: the old rifle, which had been temporarily repaired, wrapped in old rags

 

While still waiting for cool Action Videos, I decided to put the last recent Sourcecode online @github

 

 

This Schematics is some more enhanced than I really build. Some experimantal stuff which is not implemented in Software yet

Please add 10K resistors pullup for I2C, I have them at the display.

Creator: Darkdau also  known as bed in Great Cow Basic Forum