Hey I am trying to run power to the O/I through the competition port to give power to the O/I. Does any body know what pins are used for power input to the O/I. I have sen team 537 provide power from there setup through competition so if anyone from 537 or and other team knows how this would be much appreciated information.

You could just ask me… :smiley:

Here is a complete pinout of the competition port:
1 Positive Power In
2 Unknown
3 +5V to bypass P05 countdown and disable radio (put the controller into “tether mode”)
4 Unknown
5 Autonomous Enable
6 Robot Disable
8 Ground
9 N/C
10 Radio serial data in (from radio tower)
11 Radio serial data out (to radio tower)
12 Channel Access Enable
13 Competition Mode Enable
14 SDA
15 Valid RX


If you fry your OI, you’re on your own! :yikes:

Hope this helps!


Just out of curiosity, why are you trying to run power through the competition port rather than just using the AC adapter?
Something else that might be somewhat helpful. One day one of our drivers got sick of always having to get the OI close enough to an outlet to use the AC adapter and he made a battery pack for it. He just bought one of those AA battery holders from radio shack and connected whatever connector the OI uses (the same one as the AC adapter uses, don’t know what it’s called) to it. It only requires 5-7 AA batteries. (I’m not sure how many exactly, I haven’t worked with it for a few months and I forgot what voltage the OI requires)

One reason suggests itself to me immediately: you would need to make only a single connection to the competition port to get power, enable/disable, and autonomous control simultaneously. If you did it that way, you couldn’t accidentally power up the robot without having a disable switch available.

Just a word of caution: powering the OI through the competition port will void the warranty. Pretty much all of the equipment that people have right now is probably out of warranty anyway, but it doesn’t hurt to mention it in case someone decides to try this in January with their brand-new OI.

Check the schematic at: http://www.ifirobotics.com/docs/competition-port-pinout-guide-reva.pdf

Note the text in bold caps (emphasis mine):


I have done this, but it is easier to just use a 9 volt battery. That way it is the right voltage without screwing around with 6 batteries.

On our 2006 OI, we had a spot to hook up a bunch of 9V batteries in parallel. Although we never used it, it would have been very helpful in many situations provided that we actually had 9V batteries.

I made a small portable power supply for this years controller (2 9V batteries in parallel to power the OI) but the OI surges so much that all analog ports mess up. The robot will do very random things if you use the analog ports of the 15pin connectors. We used ours for many things such as our presets, extension and the hold button. The robot would go crazy with the presets, and the extension would work occasionally.

We played around with a portable power supply early this year. Having been part of the First Robotics Competition for so many years, we had a bunch of ancient 12-volt drill battery packs and chargers sitting in a forgotten corner of our shop. I found some that worked and made up a cable that plugged into the OI power input at one end and had connectors that attached to the battery at the other. The voltage was fine, and the operator could wander around the shop controlling our prototype Mecanum 'bot with nothing tying the OI to the wall.

The battery packs were not in the best shape, and only lasted for about 10-20 minutes before they would stop powering the OI reliably, but as a proof of concept it worked very well. I’m thinking we could build an operator console for robot demos that has a slot to plug in a drill battery, like the way the robots themselves were powered in the mid-'90s.

This was perfected after two years and we love it.

Our OI box has a wiring harness that is always connected the the AC adapter port, this goes to a switch; battery power or AC power.

the battery power is supplied by a standard VEX or RC battery (we put a tamiya connector in to mate to the batteris without mods).

When it is in AC power mode, there is a charging circuit similar to what was reccomend to be used on the robot this year that charges that battery.

We also used the power from that battery to power our USB chiclet.

So far, we found this to be much more elegant and easier to use than normal batteries.

Well we are doing a mini robot competition on the off season untill Jan to get the new freshman involved with inventor and the metal shop. So we needed a ‘Arena Controller’ basically that would send the enable. disable, auto, and manual signals to all the O/I’s. So we also needed someway to power all of this so thought why not go through the competition port since we already need to run a ton of cable for tha.

Hey, another question would a computer power supply be able to power and o/i with the 12v out with 4.2 volts? would it be able to power 6 o/i’s?

All O/I’s (and arena controllers) have a 9vdc Input Rating, Using a 12vdc Computer power supply would not by wise to power 1 O/I let alone 6 of them.

I suggest going here and making a cost effective portable battery pack, Simple to create and can be re-used over and over again espicially if the batteries used are rechargable and you design a charging circuit to go with it.

They want to build a field control system, so this isn’t really a suitable option for them.

Why not just buy a 9V power supply that can source enough current for 6 OIs?

Not sure what you are asking with the reference to 12 and 4.2 volts. Let’s not forget that OI is powered from 12 volts through the tether cable. But before attempting anything like this, a prudent thing would be to call IFI tech support for help. In any wiring to multiple devices, steering diodes would be a nice addition to fused lined lines for each device.

Well the O/i’s can handle up to 12vdc. right now we have 3 running at 12vdc at 1500Ma. A computer power source can do 4.2 amps. We need the amp power for running more than 3 and 4.2A should be plenty.

Technically each OI can draw up to 1000mA (1 amp!) at 12 volts.

hmm interesting… Well right now we have 3 running on a 12volt 2000Ma and there not cutting out or anything.

Keep this in the back of your head…Many computer power supplies need a minimum load current to turn on. If your power should fail at some point, it might be there is not enough current in the loads.