Updated PC software for the DIY Chrono (and Combro)

Just a quick update for anyone that has tried the PC software application for my DIY Chrono before, I've re-worked it a bit and changed the layout and moved the settings to a separate screen.

Also now I've fixed the Combro option not working so it should now report the correct values, if not please let me know as I don't own a Combro ..... the whole point in making my own.

Some Screen shots ...

Main screen interface

The main screen shows all the shot details in FPS and M/S along with a min FPS, max FPS and a Delta FPS.

On the right there is a list that adds each shot's data to a row so you can see the history.

At the bottom is a chart section that, if the checkbox is checked, shows the data graphically, there is a tab for FPS and one for energy.

You can also select the option to store the shot data to a file on the PC, the path is set automatically but you can type in your own.  The data is stored as a CSV file and can be opened by excel and used to create a graph.

Settings screen

The settings screen is self explanatory, I hope, change the settings and they are stored for next time, the pellet data etc. is stored in the CSV file as well.  If you have a Combro then tick the checkbox and the software should work for you as well

Here you can set the PC to make a noise

You can set the PC to give you an audible warning every 'n' shots, this is good for knowing when you fired your last shot and you're not looking at the screen, the other check box resets the shot count after the beep.

You can download the file from here unpack the rar file and run the setup to install.

Comments and feedback always welcome and if you like buy me a pint with the donate button.

Chronograph - Another option

After printing the last model I ran out of the white filament and decided to give the black filament a try and was surprised to get a print that looks and feels a better print, I think it's an optical illusion though, black just seems to look better.

Anyway I decided to do another design of the enclosure one without the battery for those that just want to connect to their laptop via the USB cable and us the PC software from elsewhere in my blog.

This design is a bit smaller that the first as there is no battery, switch or charging cable, I did leave in the holder for the Bluetooth module so it can be used with the smartphone app but you will need to power it from one of those portable emergency batteries via a USB cable.

You can get the STL files from Thingiverse

I've also been making some changes to the Arduino sketch to improve the functionality, I've implemented the use of interrupts to trigger the measurements so that some other things can be done via the main loop like checking if the trigger beams are blocked.

Some other options may be possible like adding and SD card to store shot data internally and use you PC later to recover the shot data for analysis, If you use a long enough piece of aluminium you could add a thread to the end to fit you silencer to and just use you gun for the day and download the shot data later.

Chronograph completed - Finally

As anyone who's read this blog before will know, there's a common theme throughout, the DIY Chronograph I made for measuring the speed of an airgun pellet.

Well since getting a 3D printer I've finally managed to finish off the project and put it in a case, it's not often I actually put things in a nice case.

The first case with the Nokia display, it was a bit clunky and easy to break, when I dropped it that is!

Second attempt, this is the one I've been using.  This one uses the Bluetooth module to talk to an app on the phone here

Collection of bits held together with heatshrink

The final one, this one contains all the gubbins from the shot above inside the cover.

The end that screws on with the USB connector below and the front
view with the on/off switch and battery charge connector

Side View

This one uses the Bluetooth adapter and connects to an app on the phone and has an internal lithium Ion battery than can be recharged using an external supply and charging module, you can leave out the battery and use the USB connector of the Nano to power the chronograph from your laptop or a battery pack with a USB power output. (if you do this then the switch doesn't do anything)

The enclosure is essentially two parts, a carrier, that holds all the electronics and a slide on cover.

Both parts are a push fit onto the aluminium tube (16mm Dia. x approx 100m long)

Parts list: -

Item	Source	Approx. cost
3D printed enclosure - Thingiverse	www.3dhubs.com www.shapeways.com	£10 - £20
Arduino Nano (could be mini pro etc.)	Ebay	£2
Slide switch	Ebay	£2
Battery (Turnigy Nano-Tech 600mah 1S 3.7v 35-70C Lipo E-Flite)	Ebay	£5
Aluminium Tube - 16mm OD	Ebay	£5
Bluetooth Module	Ebay	£4
3V to 5V converter (NCP1402-3.3V STEP-UP BREAKOUT)	Proto Pic	£4
JST wired plug connector	Ebay	£3 for 10 off
IR Emitter x 2	Ebay Farnell RS Components	RS= £2.25, 5 off
IR Detector x 2	Ebay Farnell RS components	RS=£5, 5 off
Arduino Sketch	Here	Free
Android App apk file (from Aptoide store)	Here	Free

So around £44 to put together, £24 'ish if you can 3D print your own enclosure.
You could also do away with the battery and 3 to 5V converter if you powered it from you laptop USB or battery with a USB socket on it.

More images

Battery and PCB modules in place with the tube

Barrel end showing the USB connector

Front end showing on/off switch fitted

Inside the cover

The Bluetooth module wired to the Nano

Nano and BT module in the carrier

Everything wired up... nearly. 3 to 5V converter top left under the battery

Tried and tested and working OK, the app works fine and I'm looking to add a graphing function so you can see the performance over a string of shots.

Fritzing schematic

As usual feel free to ask questions and comment below.