[kmcclary]

Originally posted by Joseph F
The conditions of the match shouldn't be far enough outside the realm of normal capabilities that it would cause the program to crash.

I've never seen the robot program actually CRASH before. Stuck in infinite loops maybe, run out of time and miss a packet maybe, but have you actually had the computer CRASH on you?

What I'm talking protecting against in a program are LOGICAL errors. For example, if a timer variable is not checked correctly, it wraps around (overflow/underflow) forever and therefore never switches things to the next state.

Given the specifics of the competition odds are a wire will be ripped off long before the program gets confused enough to crash.

Hmmm... Well, that may or may not be true, because boy oh boy, have I seen some real doozies that passes for "software" in my day... ... But, you've got a very good point that this IS a physical event and wiring COULD get ripped out. That's why we tried to run things where any Battle Bots present couldn't get at them. You'd have to break the chassis apart (or go at it with diagonal cutters in the cranny of some L-channel from the INSIDE of the robot) to get at some of our wiring.

Plus we dont have anyone who actually 'knows' how to sodder propperly, so our joints are probably sub-standard.

Have your Electronics teacher check your work. If HE (or SHE) can't tell a good from a bad soldering joint, you've got OTHER problems at your school...

(BTW... it is "soldering", not "soddering"... )

Here are a few links for you on soldering to get you started:
http://www.circuittechctr.com/guides/7-1-1.htm
http://www.epemag.wimborne.co.uk/solderfaq.htm
http://www.aaroncake.net/electronics/solder.htm
There are lots more good references on the web. BTW, for practice, I'd recommend simply taking an old PCB and some wire out of some dead home electronics appliance or toy, and solder wires onto it anywhere until you're comfortable that you can attach and detach a wire cleanly to a board or a connector.

I did program in an ovverride that turns the pump on whenever the pneumatics are fired.

What turns it off? Only time, or does it go back across the high pressure setting then run the clock again? BTW, watch out for the logical possibility of the pump trying to switch on from your override, then off because the high pressure switch has not responded yet due to lags and thinks it is still "at pressure now", then back on again once the pressure switch responds a fraction of a second later. That quick "ON/OFF/ON" cycling COULD stall the compressor if the back pressure is too great from the first short "on" burst.

As for a manual on/off/auto switch its a good idea I hadn't concidered. I'll probably set up as much of it as I can until I actually get the robot back.

If we're allowed to do it NOW (are we?), I'd just recommend making a switch with a connector on it to plug in to an unused OI port (or if you don't have an unused one make a male & female "feed through" connector to stick in series with one of the current joystick connectors to tap off the AUX1 and AUX2 pins you need for the switch). I'm not sure if that is legal now that the six weeks is over. Someone please comment on that.

BTW, we planned ahead JUST for THIS kind of problem. Our auxilary control box brought out a LOT of extra signals "just in case". We're only using three of the ports, so we fanned out an ENTIRE port connector (4 pots and 5 bits) onto a terminal strip in our Aux box, so in case of emergencies like this one we already have extra controls available and wired at our panel, ready to instrument program fixes. If we need a new control at the contest site, we drop another pot or switch of the right type with short wires hanging off the back into the box panel, connect the wires to some unused bits on the terminal strip, label it in magic marker, and just USE it... NO soldering required. All of the rest of the current controls (other than Flightsticks) are also taken to lugs and a terminal strip inside the Aux box, with spare wire length, so we can move things around to reassign them to ANY aux channel, if necessary, in only seconds. Theoretically, other than punching the new hole for the control in the box, ANY control mods OR ADDITIONS should only take minutes on site.

A good idea, unfortunately our control board has all but 1 switch in use currently. I programmed in a turn corrector controlled by our last availible wheel (our robot turns right for some odd reason).

You've used up ALL FOUR PORTS??? WOW! You must be controlling an OCTOPUS!

Does that include fanning out the extra pot and the two aux bits for the CH Flightsticks as well??? (A port has four pots and four digital bits, but a CH Flightstick only uses three pots and two of the bits). If so, that's a LOT of controls!!! (SIXTEEN pots and SIXTEEN bits!) If not though, you've got two extra bits and an extra pot available on EACH joystick that you can tap. Add an "inline feedthrough" connector (male/female pair) to a port which just brings each wire across to its counterpart for the original device plugged into it, and tap off whatever signal you need. FRCtech2002 ruled we can secure wiring with hot melt glue, so encase the entire thing in hot melt to form an insulator and make a "brick" out of it. Now you can tap into ANY unused signal pin without disturbing the thing orignally plugged into it.

wow. um. I am going through robot withdrawal currently but I havn't achieved that level of desperation just yet....

<chuckle>...

Actually its probably not as bad as it sounds, but of course this would assume I put in and soddered up the second switch. I might write the program for this eventually anyway, just for future refrence.

As I said, the program is already written for you in Team Update #5. It is only a TWO LINE program! (Plus a couple of aliases...) Just drop it in now, assign the right input bits for it, and comment it out for the time being so it's ready to roll if other things don't work out.

Thanks for all the help. I'll be printing out this thread eventually to keep all this usefull information.

Hey, no problem! Although this is our team's first FIRST contest, I've been a professional programmer and a robotics hobbyist for a LOT of years. If there is anything else I can do to help, please feel free to drop me a line.

Later!

- Keith McClary, Advisor Huron High 830 Rat Pack