Niftymitter is an open source short range FM transmitter based on the open source hardware design by Tetsuo Kogawa.

Version 0.22 is designed to be housed within a ~1mm card body, with a variety of options for hacking. The transmitter is tiny and handy for small scale radio broadcasts, building a distributed PA system for performances, linking your personal audio player to your car radio, or for general audio experimentation.

The new version solves many of the problems in v0.21 (See project website for v0.21):

• dimensions of net refined for better fit to battery and pcb, and sleeve.
• transmission seems to be fine on the whole.
• spacing and hole sizes fixed for components on PCB

v0.21 solved many of the issues of v0.1:

• a lot less bulky, more friendly on the pocket
• improved component layout, slimmer, more stable
• no nasty cable ties
• more accessible for those without laser cutting facilities - can be hand cut, or plotter cut.
• cardboard more resilient at joints than acrylic.

KNOWN ISSUES IN v0.22:

• circuit box part needs to be restrained within sleeve - fiddly when removing battery tray.
• PP3 power lead needs better access to battery tray.
• separate, powered, mic design required.

The project's home is at openthing.org/products/niftymitter

• PCB Layout v0.22 [.svg]
  • The PCB source is designed for etching onto copperplate, using iron on acetate (such as that described here http://www.instructables.com/id/Mostly-easy-PCB-manufacture/) or using Michael Shorter's laser engraving method described here http://www.instructables.com/id/Printed-Circuit-Boards-PCB-using-the-Laser-Cutte/ [instructables].
• Electronic Schematics [Tetsuo Kogawa's site http://anarchy.translocal.jp/radio/micro/simplestTX01.jpg ]
  • General support for the electronics is on Kogawa's site here http://anarchy.translocal.jp/radio/micro/howtosolder/howtosolder.html.
• Electronic Components List [Tetsuo Kogawa's site http://anarchy.translocal.jp/radio/micro/parts_simplestfm/index.html]
  • Tetsuo Kogawa's site contains all the information needed to source components and assemble the electronics using his particular copperplate method, described here http://anarchy.translocal.jp/radio/micro/howtosolder/howtosolder.html.
• Housing layouts v0.22 [.svg]
  • The layouts are designed to be laser cut and engraved, or cut and scored by hand. They are designed for ~1mm cardboard or polypropylene and can be assembled by folding and gluing with a quick drying adhesive such as UHU.