Geiger to iPhone cable

[gmusser]

I'd like to plug my Geiger counter into my iPhone and use Geiger Bot, but am running into a problem trying to follow the advice at http://mightyohm.com/blog/2012/03/how-t ... r-counter/ and http://anrieff.net/abs/viewpost.php?lang=en&id=65.

Namely, I can't find a cable that assigns a single lead to each conductor on the plug. I cannibalized an Apple cable, but found that, as Jeff noted, the mic and ground are evidently twisted together -- for each, an ohmmeter shows about 100 ohms between the plug and the wire. I bought a third-party cable, and it too had the same problem. I found a 3-conductor to 4-conductor adapter and struck out again. My local Radio Shack doesn't stock a bare 4-conductor plug, and it seems a little silly to spend $10 s&h to order a 49 cent plug online.

Does anyone have any advice?

[mightyohm]

You should be able to carefully separate the mic/gnd twisted pair and make connections to each, but for whatever reason every Apple headset I tried didn't work - when I was done I would have bad continuity. This might have something to do with the 100 ohms you're seeing between the plug and the wire!

I'd keep buying cheap headsets and look for one that separates the conductors in a convenient way. The one I link to in the blog post (Miztech) works well, but there is nothing particularly special about it - it was the cheapest headset I could find at Fry's.

[dogpilot]

The Apple cord is a bit tricky. You get a red and a green wire for left & right speaker. Two copper lines that are both common and a red/green twisted line. This line can be teased apart to reveal a white line inside of it. This white line has the mic conductor inside of it. So careful stripping of the white one will give you the mic line. Then twist the two copper and the red and green wires that you teased off the white one and solder those all together for common.

[gmusser]

Thanks! I bought the cheapest headset I could find and each wire corresponded to a different pin.

[mightyohm]

So you got the cable working? That's great to hear!