|Chrono Mark II Assembled|
- The fact that it was not a round tube but a teardrop and therefore may not always line up with the rifle and look a bit odd.
- An external charger circuit was required to charge the internal battery.
- The switch was mounted at the other end of the tube from the electronics and was a bit of a pain to wire up and assemble.
The main reason for the teardrop design was to fit in the electronic modules with the central tube so I needed to come up with a design where I could place the modules and battery around the perimeter of the tube whilst keeping the overall diameter as small as possible.
I also wanted to add a charging circuit inside the tube so there was only one part to worry about so you could just plug it into a phone charger to charge it. If I could get all this inside the tube, along with a switch located at the same end as the electronics then it would be a big improvement IMO.
First test was putting the modules around the tube .... using Tinkercad I messed around with all the modules trying to fit them in.
Having got them to all fit in a round base I set about figuring out the charging the battery and powering the Nano from the 3.6V battery as the IR receivers were specified to use 5V.
After a good Googling around for some modules I finally found some modules that fit the bill, one to convert 3.6V to 5V and another to charge a single lithium cell from 5V. These module need to be pretty small and I wanted them to be on a single PCB to make wiring up the modules easy so I designed a PCB to mount them on and had the idea to attach the PCB to the switch which would be securely screwed in to the base.
|Power PCB Circuit|
Some More Images
|Pololu 5V Step-Up Voltage Regulator U3V12F5||Link||£3.32|
|DD08CRMA Mini 5V 1A Lithium LiPo Charger Module||eBay Link||£1.97|
|Mini Miniature On/On 6 Pin Slide Switch DPDT||eBay Search Link||~£0.40 ea.|
|Power PCB gerber files||Link||£0.00|
|3D Print files for carrier and tube||Link||£0.00|