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I've got a HAT board with five status LEDs I'd like to get somehow extended to the front panel of my system, so that I can read its status without opening the enclosure. the five white rectangles you can see on the picture near the bottom edge of the board are the LEDs:

HAT board with 5 SMD LEDs

The almost obvious solution is fiber optic cable: I've got some 20 cm long PVC-coated 2 mm diameter glass fiber. The retailer suggested me to use Loctite to glue the end of the fiber to the transparent LED casing. NO USE: Everything (fiber, coating, and even my fingers, ouch!) got glued, but not the casing of the LED. Unfortunately, there are no holes or other parts I could attach the cable to, so what shall I do?

Neppomuk
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  • What fiber optic cable? Glass or plastic? – Justme Apr 07 '23 at 22:33
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    I have seen commercial products with rigid light pipes instead of fibers. – Mattman944 Apr 07 '23 at 22:44
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    You probably want to make or print a hig to put around the LEDs and hold the fiber in place. You can put glue around that. Otherwise I would remove the LEDs from the board and run wires to wherever you want them. – user1850479 Apr 07 '23 at 23:11
  • these may work ... available at party supply stores ... https://duckduckgo.com/?q=clear+plastic+swizzle+sticks&iar=images – jsotola Apr 08 '23 at 01:03

2 Answers2

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BIVAR makes light pipe adapters that can be placed over through-hole and SMT LEDs: https://www.bivar.com/light-pipe-technology-and-applications/

You can get these from Mouser and other parts distributors.
Below are are few examples:

Bivar
https://www.mouser.com/ProductDetail/Bivar/FLP5-75?qs=RaByzyhmEWjTF%252B2vDo7Faw%3D%3D&mgh=1&gclid=EAIaIQobChMIoaT2jf2Y_gIVZAtlCh1jyAaOEAQYASABEgIPAvD_BwE

Phoenix
https://www.bivar.com/light-pipe-technology-and-applications/

Nedd
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OK, I solved the issue very simply by using contact glue instead of Loctite. First I had to shroud the last millimeters of the optical fibre with shrink sleeve. Then I applied a few droplets of contact glue both on the sleeve (NOT the fibre itself, as the glue is less transparent than Loctite!), and on the PCB (again, NOT on the LED cover). At last, I pressed the end of the fibre on the PCB and LED firmly, and that was it.

Neppomuk
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    Glad to hear that you found a simple solution. In case there is any pressure on the connections (from twists or turns) you may also want to add a layer of epoxy over the whole group of connections. – Nedd Apr 16 '23 at 04:48