Problems with IR Board

[Mark McLeod]

The logic of the board appears to have it step through the learning sequence even if it isn't really learning anything, as evidenced by the learning sequence continuing even with the error LED blinking. It seems to have to recognize a valid carrier signal and will flash the error light on special protocols it cannot handle.

Anyone else learn anything interesting about their IR board?

I'm pretty sure we received a defective board, but until my sack full of remotes can be tested with another board and we find at least one to be effective can we prove it. I've tried it with remotes from more than a dozen manufacturers, and tried it with and without cycling the power after completing a learning sequence. The LEDs flash during learning, but afterwards not even the error light blinks. Ben from Diversified Systems has been helping and said they'd found a bunch of remotes that wouldn't work. e.g., wrong frequency, cable protocol.

Responses vary from:
--Immediately getting an error light (JVC--tv, Toshiba--dvd, Viewsonic--projector, Infocus--cameras, JQA--projector, Tascam--dvd, Tandberg)

--Uneventful stepping through the learning sequence, but no acknowledgment afterwards (Panasonic universal--vcr/dvd/tv,Pioneer--plasma,Barco--projector, Samsung--dvd/vcr/tv, Sharp universal--hdtv)

--No response whatsoever (old Sherwood--stereo)

[Gdeaver]

Sony IR codes where popular with the hobby robotics crowd several years ago. You might want to try several of them.

[ChuckDickerson]

We received ours today and hooked it up tonight but it seems totally dead. We tried a benchtop power supply set to ~13 VDC and a standard 9V battery. No LEDs did anything at all no matter what we did. We checked the power at the board and even connected power directly to the 1&2 (Vin) and 3&4 (GND) input pins on the 10 pin header directly via micro clips to eliminate any issues with the ribbon cable. Is it possible we just got a bad board? Anyone else have this problem? Any ideas how to fix or further test it? Anyone know how we would go about getting a replacement?

[Kevin Sevcik]

DeepWater,

It's entirely likely you've gotten a bad board, but have you checked the voltage out of the voltage regulator while the board has power? If you measure across C4 with negative on the pad closest to the ribbon cable, you should get 5V. You could measure across pins 2 and 3 of the big whit connector with negative on 3 to check as well. Beyond that, I'm not sure what it could be.

[ChuckDickerson]

Originally Posted by Kevin Sevcik

DeepWater,

It's entirely likely you've gotten a bad board, but have you checked the voltage out of the voltage regulator while the board has power? If you measure across C4 with negative on the pad closest to the ribbon cable, you should get 5V. You could measure across pins 2 and 3 of the big whit connector with negative on 3 to check as well. Beyond that, I'm not sure what it could be.

Good idea Kevin! The board is up at the shop tonight but I will check the 5V output ASAP tomorrow.

[T3_1565]

We haven't tried ours yet, but perhaps your broke in shippment?? Also, what if they were meant to work (ok so its a long shot) does anyone have their's working perfectly???

I'm going to try ours tomorrow!

[keen101]

"I broke" our board today.

It was working fine, and then all of a sudden.... nothing worked. It suddenly got quiet.



I suspected the 5V 78LO5 was bad, so I asked my dad to help me diagnose the problem. Sure enough the regulator was bad. So my dad helped me find a suitable and more robust replacement. We put in a new regulator, and now it works great again!

...My advice to anyone with a quiet board, is to check the regulator.

[MrForbes]

What voltage were you sending to the board when it fried the regulator?

[keen101]

If your question was directed at me, then here's my answer...



I was using a 7.2v back-up battery.

Doesn't seem very likely that that would fry it.

Static electricity? I was being careful in regards of using it in a static free environment.

My dad said maybe it was half (over) heated when they assembled the board. But, he even had doubts about that. He seems about as bewildered as I am.

[ChuckDickerson]

Yep, that's the problem. The voltage regulator is dead. 9V battery in, nothing out. So, should I:

a) Try to repair it? Implications: We may make it worse!, Is it even legal to do this before build season or even at all?, What voltage regulator should I replace it with and where to get it?

or

b) Get it replaced? Implications: Where do we get a new board?

[Bharat Nain]

It looks like there are a few issues with this. I would HIGHLY recommend letting FIRST know about this ASAP. This way they can hopefully figure out a solution and check to see if there is a pattern with the problems. We are yet to get ours...

[MrForbes]

Originally Posted by keen101

I was using a 7.2v back-up battery.

Doesn't seem very likely that that would fry it.

Not from overvoltage, at least!

Thanks for the reply....I wonder what's going on....

[T3_1565]

my thoughts IT'S PART OF THE HINT!!!!!! Quick somebody find something out on 5v regulators!!! ()

In all seriousiness though We are going to try this

[keen101]

Yes, it does seem strange that almost everyone who has a problem with the board is an issue with the 5v regulator.

Perhaps a design flaw. I shall e-mail someone from FIRST teams, to take a look at this page.

...as for options... I say try and fix it. Mostly because It could be cheaper than shipping it off to FIRST to get fixed. and also because I have no idea where you can get a new one at this time. Maybe try e-mailing IFIROBOTICS.com. Besides, you'll probably have access to order a new one from ifirobotics later.

We used something like a L809h. Maybe not a perfect match, but it fixed the board, so I'm not complaining. So, you should probably try and get an L805, otherwise improvise.

Usually I would not recommend trying to fix electronics from FIRST (ie. camera board), but in this case... I have no idea if there any kind of warranty that could be void. I would assume there is no warranty. That's the problem with releasing cool electronics as a game hint. You virtually have no knowledge about the device.

[Kevin Sevcik]

EDIT: Disregard the next paragraph...

I'm thinking this might be an oversight in the circuit design. The 78L05 series of regulators are rated for 100mA max output current. And the IR manual claims the circuit draws 100mA when an LED is on. Granted, that's a transient draw and the things are rated for occasional current peaks above that, but if it's been derated from overheating during the soldering process, then it could be marginal.

Of course, something could have just been shorted while you were testing it or something. At any rate, you should be able to find a 78L05 regulator of some brand at a local electronics shop that actualy carries things like resistors and caps and such. If you can find a 7805 or 78M05 regulator in a TO-220 package it'd probably be hardier, but you'd have to really try to jam it in to the same footprint, and heaven knows if any of this will be legal come kickoff.

EDIT: Whoops! I must have misread the IR manual, current draw is certainly not close to 100mA....