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I'm working on a board where I will need to mechanically enable/disable some functionality/portions of the hardware. I would like to have the functionality of a DIP switch (see below) but it feels so 1980s.

Use with flux capacitor

It seems out of place next to all my ultra-miniature leadless package parts. Has anyone come across anything more "modern" looking and that won't require me to use a fine-tipped pen to switch?

Additional Info

  • The switches are for an in-house test board (meant only for internal engineers)
  • I (the people paying me) would prefer it to cost as little as possible (so there is no time for me to implement any software solutions)
  • The switches will be infrequently changed from states (some only a few times in their life)
  • Size is a moderate concern. If it is too big it will look awkward next to all my small parts (and possibly make my board top-heavy)
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    \$\begingroup\$ Related: Choosing Configuration Jumpers - Solder bridges, 0-ohm resistors, DIP switches, pin jumpers \$\endgroup\$
    – Kevin Vermeer
    Nov 23, 2011 at 20:12
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    \$\begingroup\$ I take it that you need mechanical changes, not software, that you need low-profile modern packages, not bulky DIPs. Other than that, it's hard to guess what you want. Is this user-visible? Developers only? Frequent changes or set once? Software solutions acceptable? \$\endgroup\$
    – Kevin Vermeer
    Nov 23, 2011 at 20:19
  • \$\begingroup\$ @KevinVermeer - great input.... additional info added to question \$\endgroup\$
    – Joel B
    Nov 23, 2011 at 20:38
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    \$\begingroup\$ Personally, for a fixture I'd stick with the dip switches. Jumpers will get lost between infrequent changes, and stock room won't have any, so someone will go raid them out of something else, and then that won't work the next time it is used... \$\endgroup\$
    – Chris Stratton
    Nov 23, 2011 at 21:12
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    \$\begingroup\$ I think you've got your answer; you just don't like it. Why are you giving so much weight to subjective criteria like "seems so 1980s" and "will look awkward", when a DIP switch seems to meet all of your objective criteria? \$\endgroup\$
    – JRobert
    Nov 23, 2011 at 21:50

2 Answers 2

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Because your board will be used by internal engineers and infrequently changed, I suggest a solder-based or track-cutting solution.

A pair of pads on your PCB make a fine switch, and there's nothing that could be cheaper. Touch it with your soldering iron and some solder, and you've made a connection. Touch it with the iron and some braid and you've disconnected it.

If you want it to default to 'on' and you're using stencil + reflow soldering, just add some paste over the whole area and it will short during reflow.

Sparkfun's library has a few examples, they look like this:

enter image description here

They can be quite small; an 0402 resistor footprint works fine for this purpose and takes up far less space on your PCB than a DIP switch.

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I think the solder bridge will probably work fine if they are not changed that often.

However, I think the DIP switch would be the easiest and most reliable option. Just in case you weren't aware there are SM DIP switches available that are not too "1980's" (IMHO) and don't take up too much room:

SM DIP Switch

The 8-way one shown above is from this page, it's ~11mm long and not too pricy at £0.96 for one.

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    \$\begingroup\$ "won't require me to use a fine-tipped pen to switch?"...Nope! Just a needle instead...technically correct right? \$\endgroup\$
    – Faken
    Nov 25, 2011 at 3:24
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    \$\begingroup\$ Correct - I'm not sure how you get round the fiddly part though if you want a very small non-software solution. I would rather use a small implement than e.g. a soldering iron to make quick changes if possible. \$\endgroup\$
    – Oli Glaser
    Nov 25, 2011 at 4:03

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