[severos]

Wondering how possible is it to insert a transmitter+receiver inside those badges people pin to their bags/shirts?? if you don't know them, here's a pic
Spoiler (Click to View)[img]http://inphotos.org/files/2009/03/knotts-badges.jpg[/img]
I'm not expecting some HQ voice or long range, just something in the range of a single building, probably powered with a watch-battery since it needs to be small.
There should be a way to change the battery, also an on/off switch to save battery time, and another switch for transmit/receive.
Anyone done it before?? or think it's possible to make it that small??

[webdev77]

Probably not into a pin, but you can definitely make an FM transmitter with microphone that could fit into your pocket or inside your shirt with ease. If you google "FM transmitter circuit" you can find plenty of adequate solutions that would work for you.

[severos]

Probably not into a pin, but you can definitely make an FM transmitter with microphone that could fit into your pocket or inside your shirt with ease. If you google "FM transmitter circuit" you can find plenty of adequate solutions that would work for you.

I've seen one on instructables that was mounted on the head of a battery, but the battery it self was a bit large (9V one), so I thought maybe there are even smaller circuits somewhere.

[webdev77]

I've seen one on instructables that was mounted on the head of a battery, but the battery it self was a bit large (9V one), so I thought maybe there are even smaller circuits somewhere.

The circuit itself can be made extremely small, but for practicality of home assembly, the size of a quarter is probably the limit.