Now that the build is over and everyone is competing, let’s please start talking about the Custom Circuits everyone came up with (or wished they had)! 
IMHO, this is by far still a Mech Eng contest, but with the advent of the Custom Circuit rule that’s starting to change. As an Electrical, Computer & Controls Engineer (amongst other things), I’d LOVE to see more flexibility in Custom Circuits design for this contest. IMHO, there’s a lot of room on the robot where other sensors, signal conditioners, or cheap yet smart “bricks” could do a thing or two for you to make both the RC’s job easier, and the entire system simpler or more understandable to students.
IMO, the best way to do that is start pooling our lessons, and ideas for new Custom Circuits.
For example, WildStangs have a GREAT multichannel motor current monitor sensor set and micro that sends data back through the RC Digital Inputs. That helped them keep tabs on motor currents and overloads. (For tech info, see this thread: )
http://64.119.166.94/forums/showthread.php?threadid=3302
My questions to you:
- How’d you like this year’s rules for Custom Circuits?
- What did you make this time?
- Did it work? If not, what went wrong?
- What lessons have you learned for next time?
- What would you have done if the rules would have allowed it?
- What dream CC would you like to see someone invent?
- If you were to write next year’s rules, how would you rewrite (or expand) them to both give flexibility, yet keep it fair for the little guys?
So come on guys, lay your stories on us! What’s in YOUR wallet… er, uh, Custom Circuit??
Keith,
We started with a request from mechanical to monitor motor currents during competition and ran with it. We now have a fully functional and tested in battle current monitor, “StangSense” ™ and a portable version of the same monitor. We are able to monitor currents in eight motors on the robot, send the data to the OI and out the dashboard port to a color palm which shows in real time if we are close to tripping breakers on an individual motor. This gives our drivers some feedback during the match. What has proved more useful is the ability to download the data from the palm after the match and compare motor current demand and battery terminal voltage graphically.
We have used the mini version for two regionals now for analyzing other teams machines. Several teams have come to us with electrical questions about tripping breakers and resetting the interface. With a few jumpers added to their robot we were able to pinpoint an offending motor or potential problem.
We will be in Florida for the nationals so if you are having electrical problems stop by our pit and ask for help.
Good Luck All
Sorry for the confusion, Al. I didn’t mean the questions were for you. You’ve already done a good job explaining StangSense in the other thread. (BTW… StangSense is a {i]great “product”! Keep up the good work!)
When I asked: “My questions to you: [are…]”, I was hoping EVERYONE would come on out of the woodwork (or their shops 
) and talk about THEIR experience with CC’s like you did in the other thread.
Hmmm… maybe I should have used the southern “Y’all” instead of “you”…
So “Y’ALL”, anyone else use a Custom Circuit this year? If so, please come on out and brag about it! Please see my original post for the questions.
Thanks!
We used a very simple design. We are using 4 solid state 12V DC relays for our four drive motors. We connect the power to the relays to the output from the fuse panel to the Victors controlling the motors. When the Victors lose power the relay trips a digital input. We have four LED’s on the operator interface to show when the motors are tripped. The base driver also has special glasses with LED’s in the side to show them the same thing. That way the driver knows when to let off and the arm driver can hit em if he doesn’t slow down. Redundency is good.
Our custom circuit contains a Traction Control System that is designed to prevent slippage of our tank-tread drive system. How this system works will be disclosed after nationals
Making all of these custom circuit boards are great, but where’d you get the circuit boards themselves to begin with? Did you make them yourself with the radioshack-type etchant solution, copper board, etc.? or did you go to something like pcbexpress and have them do it for you?
I looked at pcbexpress.com, and I was thinking of ordering from there, but I didn’t know how to make the picture they require for the drill holes and overall layout.
Well Gui,
Consult your Digikey catalog and you will find a series of proto boards by Vector and others. That is what we are using. It is easy to wire and modify, easy for students to hold and solder. and with little modification fits inside the Budbox.
Good Luck All
*Originally posted by Gui Cavalcanti *
Making all of these custom circuit boards are great, but where’d you get the circuit boards themselves to begin with?
http://www.RadioShack.com/ sells PC boards which already have places to mount components and pads to solder them together. You can use them to build just about anything.
They even sell breadboards and matching PC boards if you want to design and troubleshoot on a breadboard and move everything directly to a PC board.
My problem with this year’s rules is that it doesn’t allow us to use external hall-effect current sensors, so to use them, we would have to run our motor wires through the box. If they allowed external sensors to be added, that would be great.