Plantronics Phone Indicator Light Hack




About: depotdevoid is short for The Depot Devoid of Thought, the place where you go when you lo...
Several years ago, when I was first getting into instructables, I was given a phone in use indicator light to go with my Plantronics headset and phone lifter combo at work.  I hate it when people talk to me when I'm already on the phone, and I thought this would help,  Sadly, the out of the box equipment was pretty dim, and not visible to everyone who might decide to strike up a conversation while I'm already having one.

With soldering iron in hand, I set about irrevocably altering company property without permission.  I figured I knew enough about electronics to spice things up a bit.  At the time I didn't think anyone else would find this idea useful, so I didn't take any process photos.  Over the years, I've begun to notice just how many offices use these same headsets--they're everywhere!  I don't think you'll have any problems though, this is a pretty straight forward operation.

Here is what you'll need to build one of your own:

  • A Plantronics wireless headset and indicator light
  • Some sort of IC socket (available at radioshack, online, or in your old and busted electronics)
  • LEDs of various sorts 
  • Perfboard
  • Speaker wire
  • Solder
  • Hot glue
  • Magnets (optional; I needed these to attach the board to the metal part of my divider wall, you may or may not need this)
First, crack open the case.  On the front face of the circuit board are the five surface mount LEDs, sorry but no picture of them in place, you can see where they were in the pictures though.  Carefully desolder and remove each one, making sure to keep the pads intact when you do.  Once they are removed, attach a short (6-8 inch) length of speaker wire to each pad.

On a strip of perfboard, attach five IC sockets.  Solder all the legs on each side of each socket together.  Attach a speaker wire to each socket, the positive end of one side and the negative on the other.  Now you will be able to drop an LED into each socket, the negative leg on one side and the positive on the other.  

Glue some magnets to the bottom of the perfboard strip so it can attach to something metal (in my case, the top edge of the divider separating me from the front of the office).  All done!  At this point I spent a bunch of time collecting LEDs to be used in this device, from my already vast collection, from old electronics, and from LED Christmas lights.

The result was pretty awesome, and changeable to suit my whims.  Most importantly it had 360 degrees of visibility.  Still, it wasn't bright enough for my purposes, so I ended up giving it to my mom.  I built an even grander version recently, and if you'd like to see a full instructable about it, follow/subscribe to me, I'll be posting it in the next couple of days (EDIT 6/20/11  --  full 'ible about my final in use light is live!).

Please take a moment to rate, subscribe, and comment!  If you build your own version of this, make sure to post a picture in the comments below, I'll send you a digital patch and a three month pro membership!



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    6 Discussions


    2 years ago

    It seems that pin1 (what I'll call the connection closest to the cord) is ground, and the tip (pin3 for posterity sake,) is about 8.6VDC when the headset is not in use. When it is in use, it drops to a steady 8.4x (<8.5) VDC. So, if I can rig up something to sense the drop in voltage to trigger a relay to turn on a light, I'll be golden... In fact, that's just what I'll do. I'll post my results, so we won't need the Plantronics equipment. I'll probably spend more money doing this, than just buying the darn thing, but oh well...

    1 reply

    Reply 2 years ago

    This is for the 3 pin 3.5mm standard audio cable plugged into the lifter or in my case the cable that goes from the headset to the phone.


    6 years ago on Introduction

    Have you found a way to actually "hack" it without using the plantronics indicator accessory? Meaning connecting lights straight from the headphone jack. I can't seam to figure out how it gets the signal. I have roughly stable 5v dc between Pin A (left) and Pin B (Right), phone on or off, but nothing (DC, AC or short) between Pin GND and Pin A or Pin GND and Pin B. Any insight?

    1 reply

    Reply 6 years ago on Introduction

    I couldn't figure it out! My first iteration of this plugged directly into the headphone jack, but when it was plugged, for some reason the lifter wouldn't function.

    Eventually I moved on from this idea to my Insanely Bright Phone in Use Light, but that's powered by a wall wart.  Let me know if you can get yours working directly from the jack, I'd love to see an instructable on the subject!


    7 years ago on Introduction

    I remember those red-light-on-phone indicators at an old job I had, they are never any good.

    Way to modify company stuff! It's always easier to beg forgiveness than ask permission! And, who's going to argue with ze terminator?

    1 reply

    My boss gave me a bit of a raised eyebrow when he saw what I'd done, but he never said anything. Seriously, that guy puts up with a lot of crap from me!