The left side of the shell, has the safety switch, and 2x hall effect sensors for magazine size detection. There is an 8pin connector to disconnect it from the other side, makes it easier to work on.

The right side of the shell. You can see all the various bits and pieces. In hindsight i'd have used a nano extension board and put it in the battery bay, would have made hooking everything up easier. The joystick isnt visible as its under the magazine release mechanism, and the voltage/current sensor is mounted flat on the bottom of the battery bay so cant really be seen. 

The magazine insertion switch, and jam door switch are the existing switches in the blaster, just re-purposed.

The paint needs finishing and detailing (and stripping in the case of the trigger), but here you can see the screen and joystick. The joystick can be reached by the trigger finger.

I'll have a video up later today.

The current monitor isnt currently connected. I double checked the specs after jwasko mentioned the motor current draw, and it wont handle that much. Plus there are warnings about using it for inductive loads like motors that have rapid starts/stops. So for now its just doing the voltage.

I also need to tweak the position of the firing detection switch. When i tested it unassembled i didnt know that part of the jam door stops the plunger. I'm only out by about 1mm though, so easy fix. Might be able to get away with just bending the lever on the switch a bit.

Current working complete circuit diagram.

oh my god the little beep beep, I love it.

hahaha, well i figured it should have something to tell you its out of ammo or locked or whatever in case you're not looking at the screen.

A couple of clips, showing the mag size detection working, the safety switch indicator, and the jam door indicator. The screen is a bit hard to read hence the better pic below. Can see the shooting mode joystick change the mode, and the relative shooting. Regardless of shooting mode it stops at 00. Also buzzes if you pull the trigger with no ammo or if the jam door is open. Note that its not shooting at full speed, it can go faster but i'm trying not to cook the underpowered h-bridge until the new high power one arrives.

A closer view of the screen, sorry bit hard to read on the camera. The flicker is also from the camera, not the screen.

https://youtu.be/8RlWPoPg8PU

The screen layout:

- The mag number at the top shows the size of the loaded magazine regardless of the number of rounds left. Works the same as my others, uses hall effect sensors to detect a small magnet on the magazine

- "LOADED" says "INSERT" when theres no mag, or flashes "RELOAD" when its run out.

- Jam door open, obviously only displays when the jam door is open. It also prevents firing while open so I dont chop my fingers off.

- The round counter, self explanatory

- The battery voltage updates every second. ( i need to tweak the redraw slightly, the 4th digit is a bit messed)

- The current draw as mentioned above has been disabled, but i havent removed it from the screen yet

- The mode 1 3 Auto sets the firing rate. This changes to "Safety" if the safety switch is thrown, and prevents shooting. Controlled by a small joy stick.

- Pulling the trigger when the safety is on, or it has no ammo makes a buzzer sound twice.

(the screen looks better than this IRL, remember its only 1.8" diagonal)

I actually managed to mount it just above the magazine release switch. That way it can be reached by the trigger finger without having to change grip at all.

And, with that, mechanically and electronically its finished!

The software is 95% done, everything works, but i'm just making some tweaks to the screen layout and getting it all working just how i want it.

Yeah i wish mine was still on one board like it was to begin with, before i zapped it. In hindsight i really would have used one of those nano expansion boards, has a 5V regulator onboard too.

Feel free to use my code, might give you some ideas, though i dont claim its perfect!

Here is a parts list. The ebay links are just examples of the types i used. 

Here is a copy of the current arduino sketch

https://drive.google...iew?usp=sharing

You'll also need the following libraries:

Adafruit INA219 voltage/current monitor https://github.com/a...Adafruit_INA219

Adafruit GFX library for LCD's https://github.com/a...uit-GFX-Library

Adafruit ST7735 LCD driver https://github.com/a...-ST7735-Library

I dont like the blaster parts one, too much on the outside, i wanted internal so made my own.

http://nerfhaven.com...nd-rapidstrike/

Design and parts list there, happy to share arduino code if you want it.

You're right in that the 3 resistors on the buttons aren't really necessary. The ATMEGA328 has internal pullup resistors, so when you set the pinmode in software, if you set it as pinMode(pin#, INPUT_PULLUP) to use the internal pullup instead. 

Save a few cents! lol

Typically you're going to have to design most models yourself. I found very models for the parts i wanted to print on mine.

A good set of calipers to measure, and i tend to use Sketchup to draw parts.