I have several circuits which I need to turn on and off wirelessly. The rules are:

  1. They are placed inside a transparent small box (about 50x50x50 cm)
  2. The control unit\transmitter can be placed anywhere outside the box, and has no power\shape\size\cost limitations
  3. I have about 10 circuits which need to be turned on and off individually. Each circuit has it's own set of batteries (3 x 1.5v) and consumes about 1.7mw
  4. It has to be very low weight - less then a gram
  5. Very low power consumption - on the orders of milliwatts

I have two directions, but not a good way to implement any of them. The first is to use IR with modulation, and the second is to use RF.

Any ideas? Thanks.

  • \$\begingroup\$ What is the range? \$\endgroup\$ Sep 23, 2012 at 12:28
  • 2
    \$\begingroup\$ Less than a gram probably eliminates any canned modules with RF protocol, like WiFi or MiWi. IR is probably the best to look into if line and distance is OK. Also milliamps is a unit of current, not power. \$\endgroup\$ Sep 23, 2012 at 12:37
  • \$\begingroup\$ Hi Leon and Olin, I've edited the question after your remarks. The transmitter can be anywhere outside the box. And Olin, sorry for the mix-up. \$\endgroup\$
    – Oren Wolf
    Sep 23, 2012 at 12:44
  • \$\begingroup\$ Haha wireless activation "weight - less than a gram" - how is that even possible? \$\endgroup\$
    – boardbite
    Sep 23, 2012 at 13:20
  • \$\begingroup\$ Boardbite, I didn't say it was easy... For example, I've tried looking at MEMS devices which theoretically can be much lighter. \$\endgroup\$
    – Oren Wolf
    Sep 23, 2012 at 13:33

1 Answer 1


What about a photodetector and transistor as the receiver - the transmitter could then be a torch which have to shine on a device to switch it on. This is the simplest solution I can think of.

If you are thinking higher tech communications the lowest power and I suspect lightest RF solution might be a the Texas instruments CC430 Microcontroller which has integrated RF. You could of course remove the packaging to reduce weight.


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