Building an arena controller

[Alan Anderson]

Originally Posted by miketwalker

As for selecting channels, you can make switches for the competition ports (or interface them to a computer) to select the channels. Teams do it all the time for offseason competitions. It's all in documented resources on the Innovation First website if you look around, it's been done for years.

Are you sure about that? The channel selection is in none of the documentation I have found. In fact, the competition port pinout guide explicitly states that connecting to any pins other than the four called out (ground, disable, autonomous, and practice) will void the OI warranty.

The three offseason competitions I have attended either used the official IFI field controllers, or had the radio channels set manually using the OI switches.

[Mike Hendricks]

Originally Posted by Alan Anderson

Are you sure about that? The channel selection is in none of the documentation I have found. In fact, the competition port pinout guide explicitly states that connecting to any pins other than the four called out (ground, disable, autonomous, and practice) will void the OI warranty.

The practice switch enables you to use that row of 4 switches to change the channel. Check the OI manual for the channel settings.

Edit -

Some channels will go blue, others will go red. Just keep trying different channels on the OI until you get the color you want (it seems like the first 2 or 3 were red and the rest were blue .. or was it the other way around .. )

[cdawzrd]

Originally Posted by PhatMike

The practice switch enables you to use that row of 4 switches to change the channel. Check the OI manual for the channel settings.

Edit -

Some channels will go blue, others will go red. Just keep trying different channels on the OI until you get the color you want (it seems like the first 2 or 3 were red and the rest were blue .. or was it the other way around .. )

The practice switch doesn't do anything with new OI's... you just have to have the team number > 2048 (MSB set). I had also thought that I remembered there being an uneven number of colors, like 4 red and 2 blue or something. I read something on it but I can't find it anymore... does anyone have a link to where IFI said what channels produce what colors?

[Alan Anderson]

Originally Posted by PhatMike

The practice switch enables you to use that row of 4 switches to change the channel. Check the OI manual for the channel settings.

miketwalker was talking about using the competition port pins to set the channel, not the OI dip switches. The 2005 OI doesn't use the practice pin anyway; the documentation I can find says that the channel select switches are always active. (That's not exactly true; you have to set the team number's high bit before you can escape channel 40.)

[Mike Hendricks]

Hmm .. I wonder why they stoped using the practice pin. My fault on spreading wrong info .. I know we used the practice pin last year without any problem .. and since the RC/OI sets are almost the same .. I figured there wouldnt be any problem.

Heres the offical word from IFI

http://www.ifirobotics.com/forum/vie...f3520b b85074

http://ifirobotics.com/docs/oi-ref-guide-2-21-05.pdf - Page 16 lists the channels and the switches you need to set. It doesnt say the colors however.

[CJO]

I built a field controller based on the edu controller. What pin on the competition port is the e-stop? In order to effectivly control the units, i hooked the power supply up to a relay, and used Kevin Watson's ttl interface to control the system from a laptop. It was an arena controller uber ghetto edition, but it worked. I talked to one of the IFI people. They are somewhat touchy about the chanell changing, however, I think that they might be willing to release the e-stop and disable ports, because of the safety issue related to running a scrimage w/o e-stop and using powerdown to disable.

Finally a note on the field controller. Hatch chose to create a system this year in which there was no hardware control panel. As a result the official field had as long as 2 sec latency between a robot disable, and the actual robot disable.

[Mike Hendricks]

Originally Posted by CJO

I think that they might be willing to release the e-stop and disable ports, because of the safety issue related to running a scrimage w/o e-stop and using powerdown to disable.

Finally a note on the field controller. Hatch chose to create a system this year in which there was no hardware control panel. As a result the official field had as long as 2 sec latency between a robot disable, and the actual robot disable.

Intresting. I thought that the e-stop was just a disable button for the drivers. I doubt they would use another pin for the e-stop when they could just use the disable pin. I'm not sure thou. Might be something to ask the IFI people if such a pin even exists.

As for the latency, I recall seeing that. Following the auton, it seems like there was a long delay (well .. a couple of seconds) between the human control sound playing, and the humans actually gaining control. At Sac, I also remember seeing a robot not getting disabled when the human player jumped off the pressure pad. My jaw hit the ground when I watched it happen, I only saw it once thou.

[CJO]

Two thoughts,

The e-stop on blue #3 did not work at SVR. We tried several things, and could not re-enable the e-stop.

As for the latency. I believe that there is ~1.5 sec between the end of autonomous mode and the beginning of driver control designed to allow field attendants to remove the hanging tetras.

Finally, at SVR we observed that the real time scoring frequently increased the field latency. Also, we had some communications problems with the team number displays.

[Billfred]

I am no IFI rep, but in my experience the E-stop buttons have always used a DB9 port setup. Those plug into the controls at the alliance station, which then go on their sweet merry way.

I've always wondered what could be traveling through such a port. I've got a donut* for someone that tells me.

*Delivered off of the arena site, of course.

[CJO]

As far as I know (from an IFI rep comment at sac last year), they only use two pins of the DB9 port, they use that format simply because of the ease of disconnecting and the fact that there is only one DB9 port on each field controller channel.