Let's Make Robots!

Easy Freebie LEDs

A quick tip for all you cheap skates out there. I've always had it in my head that I would like my robot to have no permanent connections, to allow me to experiment and reconfigure. This also has the nice side effect of less soldering for me to mess up. I actually have a cunning plan to pay my flatmate in jelly beans to do the tough bits for me; he's an electrical engineer (rock!).

Freebie electronics on my scabby table

Anyway, I thought the ideal way to attach the various bits and bobs would be to use the jumper like pin connectors like you see on the end of the front panel switches and lights in a PC case. Take one of these and pop an LED or whatever on the end, then assuming you have the right output chip plugged in, you can just shove it on the board and go.

Unfortunately I have no idea what these things are called (anybody?) and so have had a devil of a time trying to find anywhere to buy them. Then it occurred to me that I could just scavenge them from old PC cases. Only later (and this is actually rather embarrassing) did it occur to me that quite a few of these already have LEDs and switches and other interesting things on the end.

I had a word with the sys admin at work and he said I could pick through some old cases that were getting thrown out. Anyway here is the haul from 3 old cases:

  • 7 x LEDs
  • 2 x 8 Ohm speakers
  • 4 x switches
  • 2 x audio jack sockets
  • Lots of little PCB connectors

Not bad eh? And quite a few ready to plug onto a board straight away. I'm sure plenty of you had figured this out already, but if you have a friend chucking out an old case shout: "Stop! My robot needs you!"

So does anyone else have any good ideas of where to pilfer other electronics?


free_electronics_bits_psu.jpg

Update

Following jklug80's suggestion of marmalising an old PSU, I broke out my trusty soldering iron and set about it. You can see my haul on the left there. Some of the stuff is crazy high voltage components that I'll never touch, but there are a few goodies amongst them. Mostly a fat tray of capacitors of varying sizes, ranging from teeny ones to ones you could put in a sock and kill a man with.

One of the interesting bits was a rectifier in a component, which could save some mucking about with diodes, but unfortunately has a minimum operating voltage of 50V. Boo. On the plus side I got to grips with the soldering iron a bit more and learned some lessons. Some burny hand lessons... I guess it has to be done.

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Cool! I like the long speaker! :D 

/ Fritsl

"Skiphoking," or "binhoking" is one of my favourite passtimes. It's a crime the good stuff some folk throw out!

God created the integers; all else is the work of man - Leopold Kronecker

Great! I'll go and scavenge my old pc :)

Btw i've been searching for those connectors for a while, for the same reasons as you (less soldering and easier disassemble). My local electronic shop does not sell them. That sounded strange to me, as i thougth they would be rather useful. I don't know how they're called.. You can see i've used three of them on my robot, two of them are taken from an old mouse cable.

I've got some of those connectors. I bought a big bag of 3-way ones. They're just 0.1in SIL jumper cable housings with crimp sockets. To tell the truth, they're a pain in the ass. Finding the correct crimp tool is next to impossible and the crimps are not very good anyway: I usually end up soldering them on, which would defeat the purpose in your case!!

God created the integers; all else is the work of man - Leopold Kronecker

I tossed a few old PC power supplies that are ripe with wires leading to plastic connectors. You have frayed wires at one end, but the other has a nice connector. IDE cables are awesome too, but are typically much larger than what you need.

Those are the internal audio cables on your bot aren't they Nicola? I've been hoarding them for years, now I know why!

And good idea about the PSUs, I have a few dead ones about, I'll crack them open and see what lurks within.