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I have this data logger that we are using for temperature and rotation measurements. Unfortunately it came with an LED, which we need to get rid of for our study.

I really don't know much about circuits, so I was wondering:

  1. Can I just remove that LED by breaking it off, without damaging the other parts in the circuit?
  2. What is there to consider doing it?
  3. Could removing it, in any way, influence the sensors on the board?

Also, I know that those logger can be equipped with light sensors. Is there any way that this Led is in fact one of those sensors? In that case I really don't want to loose it.

Thanks!

Edit: Here are better pictures enter image description here

enter image description here

Unfortunately, I don't have the schematic.

Joris
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  • No, you can't just break the LED off. The rest cannot be answered without documentation. – Matt Young Mar 17 '16 at 17:13
  • 1) You can, but you should replace it with a wire to maintain consistency 2) iron and braid 3) if you don't burn them, no 4) I don't see any other component that could be a light sensor. the exact reference of the board, and its datasheet could help – MaximGi Mar 17 '16 at 17:14
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    If the problem is the light it emits, you could paint it with, say, dark nail polish. – Ricardo Mar 17 '16 at 17:19
  • If you MUST remove the LED, desolder it. That way you can always solder it back in if you need to. It's the safest way to do what you ask, and easy to revert. – DerStrom8 Mar 17 '16 at 17:25
  • @Ricardo You're right, I did consider that. The thing is that the logger will be as hot as 41°C for many days, and I don't know how well the nail polish would hold up.. – Joris Mar 17 '16 at 17:26
  • Why do you need to get rid of the LED? – Matthias W. Mar 17 '16 at 17:27
  • @MaximGi So just in case I brake it off, I definitely have to re-connect the two ports it was soldered to? – Joris Mar 17 '16 at 17:28
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    @MatthiasW. It is being placed in an artificial bird egg for a study, and the bird would never accept it as one of its egg if it glows bright red every few seconds – Joris Mar 17 '16 at 17:29
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    Replacing the LED with a jumper wire may lead to exceeding the current limit of the sinking/sourcing device. I would only recommend this if trying without the jumper doesn't work. – Chad Kennedy Mar 17 '16 at 17:30

2 Answers2

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  1. Yes you could break it off, but that can lead to broken traces. It be smarter to just cut the trace going to or from it. An exacto knife works great. Alternatively you should desolder it, or the resistor going to it.

  2. Without a schematic, it's just an educated guess, but, no it shouldn't. I'm assuming the via on the left of the LED is Ground, and the LED only used as a simple status light.

  3. It's possible, but unlikely. LEDs can detect light too, but there are better ways of doing it. Is the LED lit when the module is powered? Then it likely isn't being used as a sensor.

Community
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Passerby
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  • Yeah, as soon as I connect a LiPo it lights up, and keeps blinking every few seconds. Unfortunately I don't have a schematic.. Thanks a lot! – Joris Mar 17 '16 at 17:16
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One thing to consider is that if you just rip the LED off, the copper pads on the PCB will most likely come off with it. That could be a problem if the pads are used to connect two traces. I can't quite tell from the pic if that's true or not. If you have access to a soldering iron or hot air rework station, I would definitely use that to desolder the LED instead of ripping it off.

The LED here is almost certainly used just for showing some status, so taking it off shouldn't affect the sensors negatively, except as I mentioned above.

While LEDs do exhibit some photoelectric effect, they're not very good light sensors, and hopefully one of the other components (maybe on the other side of the board?) is a proper light sensor.

Also, just FYI, next time you ask something like this you can get MUCH more accurate answers by providing the schematic, and even the Gerber files if you have them.

Chad Kennedy
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