New version of the Chronograph

Latest project update for 2026 here

Yes I continue to find new ways to do the same thing again ..... and again, this time I wanted to learn how to program the ITEAD Nextion display which I got when they were on Kickstarter some time ago.
I have a couple of these 2.4" screens but not really got around to doing much with them so I thought about having a small touch screen chronograph remote connected to my pellet sensor fitted to the end of the rifle.
About the screen
The screens, made by ITEAD, come in various sizes and use resistive touch screens (Capacitive also available) and come with a full editor to allow you to design you whole interface layout including screens, buttons etc. on the PC and then download it to the screen.   The interaction/control can then be done via the serial port by an Arduino or other MCU.

I have a Brocock Compatto air rifle that has a picatinny rail under the front end of the stock and I planned to mount the screen on that rail.

For this project I started on the hardware first rather than my usual approach of starting with the software first.
The Hardware
I designed the hardware in Tinkercad making a front, rear, picatinny mount and the tube to hold the IR LED sensor assembly it looks like this

In the rear half of the case the battery, Nano and power PCB are mounted the front houses the display and also forms the mounting bracket to  secure to the Picatinny rail adapter.