294 Proto Board and Battery Cart

We have had some teams over to our shop and one of the items that gets rave reviews is what we have done with some of our old control systems from the mid 2000’s. We call them proto boards as we use them for prototyping as well as a quick way to power a mechanism. The proto boards have a main breaker, breaker panel, control board, 2 motor controllers and a joystick. This allows us to connect motors to the motor controllers and control them with the joystick. We have multiple boards and are our most used piece of equipment during prototyping. If you have some old control systems laying around maybe you can have some students make something like this and put those old components to good use.

Also I couldn’t remember what thread I posted in a while ago but someone asked me about our battery cart and I said I would post pictures of it. The cart has the battery charger mounted in the middle and we can charge 6 batteries at once with storage for an additional 4. The shelf on the top right is where we velcro out battery tester so that there are no excuses not to check the battery level before each match.

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If you don’t have any old control systems laying around, VEX Cortexes or an Arduino set up for PWM output works as a simple a replacement. If you’re more electronically inclined, there are a few ways to just wire up a potentiometer and a 555 timer chip as a PWM generator. We use one or two test boards for pretty much all of our prototypes and it makes wearing in gearboxes much more convenient.

If the goal is to generate a PWM signal for a motor controller and you don’t just have stuff lying around, the Thrifty Throttle is hard to improve on for a single-channel setup. If more channels are desirable, the Cheap and Dirty controller or a similar basic R/C system fits the bill too–you just need to provide power to the receiver through a power supply or UBEC (which is simply a DC-DC converter designed with this particular application in mind).

(Full disclosure, I used to work at AndyMark.)

Those batteries being out of order bothers me unnecessarily.

There’s often a mix of 2017 batteries, and during outreach events, even 2016 and 2015 batteries charging on it, so keeping them in order isn’t really worth it, since they’re always moving slots.

Servo tester. $1.25 shipped from China.](https://www.ebay.com/itm/Multi-RC-Digital-ESC-Servo-Tester-3CH-ECS-Consistency-Speed-Controler-Power-FU/153099581403?epid=2148788103&hash=item23a57237db%3Ag%3ARY4AAOSwLIhZg2dU&_udhi=2&_sacat=0&_nkw=servo+tester&_from=R40&rt=nc) It’s a 556 (ie twin 555s), a potentiometer, and a couple other components wrapped in a piece of cardboard.
If you want nice PWM, buy AM’s product or set up your own microcontroller, but Ether’s bought five or six of these from different vendors and they’ve all worked fine as motor controllers.
Search for his posts for details

EDIT: Can 294’s setup use the joystick to do turning/etc on a tank drive or similar mechanism? That would definitely tip the scales towards this kind of a thing. I’m working on a test board for our team that will just use the servo testers though :slight_smile:

I weep for your batteries.

294’s Batteries: OUTWORK US

Cool solution from AndyMark. The idea is less about signal generation and more about an easy way for students who are prototyping hook up a motor and battery quickly for testing. Our team uses powerpole connections which means that all of our motors have these on their pig tails making it an easy connection to this board with an extension cable.

The idea of sharing it is for teams that might have some old electronics laying around and put them to good use. It also is nice as it has multiple motor controllers so it allows for connection to gearboxes with multiple motors.

One thing we (used to) have is the Gunn gun - it’s a 12v drill with a switch and a set of powerpoles tacked onto it. Turn the switch, and instead of turning the drill when you pull the trigger, it powers the powerpoles. We quite liked it, however the batteries seem to have all died at this point, so now it’s a a member of the “formerly useful piece of scrap that could be made useful again, but nobody has found the time to do so” pile.

If you’re wondering why we call it the Gunn gun, that’s because we originally got the idea from team 192 (Gunn Robotics).

I pulled some old electronics and might try it. Did you re-program the controller or just aim for drive motor outputs from the old code?

Also, I am considering whether to downsize some of the old joysticks and electronics (more operator interfaces than RCs on account of some of them still on old robots), and if anyone is considering this without the parts, send me a PM to inquire.

We had some mentors a long time ago build these boards and they programmed them. I am not sure we have someone that would be able to program them currently, or a computer with a serial port to connect it to… However you wouldnt need to change it if you knew which PWM outputs were for your drive train and hook up the motor controllers to those outputs.

B Thanks for a trip in the way back machine. The IFI hardware was reliable and easy to use. Not very fast or as versatile as current hardware. The electrical breaker has a fatal flaw and that is why it was retired long ago. The breaker was sensitive to vibration (as occurs in robot interaction) and would cause it to open. If you merely tap the side with a screwdriver handle you will see what I mean.

As to the battery cart, I am familiar with your charger. It is meant to be mounted horizontal so that cooling air moves from bottom to top. when mounter vertical as shown the heat will rise from one channel to another, causing heat stress in the charge units at the top of the case. This will lead to early failure of those units. The heatsinks (visible through the slots in the case) are not oriented for optimum air flow when mounted as you show.

Thanks Al for the tips.

For the battery cart its been pretty much rock solid for us since 2011. Other than new fuses in the charger (power surge in 2013 wiped out several) it has been performing superbly well. but I guess YMMV. Maybe a fan to blow some air would help. After seeing our teammates 67 and 177 just roll up with a cart and plugged in back in 2010 Einstein we had to have one. The cart has been such a great help for us that we use it everywhere. The cart was fully student designed and built(with some powder coat and welding help from a sponsor). We can dig up old CAD for anyone who wants it.

For the protoboard, It also was student build after seeing how much of pain prototyping with drills were. The programming was updated just to be a simple motor control using the first couple PWM pins. Old Drive code would work as well, provided that you didn’t do anything funny. We haven’t reprogrammed them in forever, so here is hoping that we remember the next time we do it. Sounds like a good whitepaper for the team to write. We have been trying to figure out good things to do with the old cRios… but being paperweights seem to be our current solution…