At a few competitions I’ve attended, a phone stopwatch and the manual competition switch have been used in lieu of field control for skills runs, resulting in run times off by up to a few seconds due to human reaction time errors. I understand why they decide to do this, it’s not exactly convenient to run skills through the official control software, especially if you want multiple fields running at once. That’s why I’m excited to release a design I’ve been working on off and on for over a year, a battery powered skills timer that can effectively replace the functionality of field control in a portable form factor.
The board has functionality for both regular competition and skills modes, for both VRC and VEXU, and has four controller ports to allow it to run a standard match at scrimmages or anywhere else where full field control is not realistic. A single rechargeable AAA battery should easily be able to power it for an entire tournament.
If anybody in Arizona is hosting a tournament/scrimmage and wants to make use of these, I have two of them I can loan out, so let me know.
The design is based around a Microchip PIC16F18325 microcontrolller and a Newhaven Display NHD-C0216C17 LCD screen. I specifically chose the PIC16F18325 because it’s supported by the MPLAB Code Configurator, which made my life substantially easier when setting up the code for the board. For those of you planning on going into any kind of embedded software, if you’re using a Microchip microcontroller, I highly recommend you make sure it’s supported by MCC, it really does make a huge difference. I had originally planned on using an external oscillator for better accuracy but, after testing, the internal oscillator was accurate to within about 0.2%, which is definitely within the range I would consider to be acceptable.
This design is completely open source, so if anybody wants to make their own, please feel free. It does use some fairly small surface mount components, so this is definitely not a beginner soldering project to assemble.
So that’s actually an interesting question. Since I made this at work, it’s not my intellectual property, but I was also told I could release them as public domain, so theoretically I (or anybody else) could probably sell them? I’m not a lawyer, so I have no idea.
It’s more the fact that it’s automated for stopping. But I think I could build one for well under $50 with an ATMega chip and a little 2 line LCD. The custom board would be the worst part, and even that wouldn’t be too bad. I might toy around with it now.
This switch acts kind of like tournament manager. It does Skills (gives control for 60 seconds, then turns off automatically) and matches (15 seconds of autonomous, 1:45 of driver control). So it is not just a normal competition switch.
Yes, of course. I’m just curious for comparison. I don’t know if the raw materials for the auto switch cost $5 or $100. That is where my true ignorance lies!!! If the cost is less than $20, someone should definately start selling.
I wonder if this could be made into one of those soldering practice kits (buy the PCB and all components; solder it together yourself). Obviously the microcontrollers would have to be resold after being programmed though – not sure how feasible that would be.
Yeah, you could definitely make it for less than $50. The most expensive part is the LCD at $10 in unit quantities, PCBs are actually pretty cheap.
Yeah, I had considered designing this to be easily solderable, but that would require a redesign with through hole components. If there’s interest I’d be happy to do that though. Programming it would definitely be the trickiest part, although if a few local team pooled their resources, buying a programmer isn’t absurdly expensive, the PicKit 3 is only $50 through DigiKey and you can probably find them elsewhere for cheaper.
