I am making a circuit using my RF TX and RX on 315 Mhz, already paired, and I have done the following circuit: powering it with 5V and GND from arduino: enter image description hereenter image description here And the picture of the circuit done: enter image description hereenter image description hereenter image description hereenter image description hereenter image description hereenter image description here

when I power the circuit up, the LED which would be suposed to be on default dont light up.. what may be wrong?

  • 2
    \$\begingroup\$ Did you really need to post that many images (without the full URLS, no less)? \$\endgroup\$ Nov 16, 2012 at 2:43
  • \$\begingroup\$ he's new. truncated www paste works better \$\endgroup\$ Nov 16, 2012 at 2:46
  • \$\begingroup\$ @Richman: I know but, (and I'm going to sound like Olin here) it should be easy to see how inconvenient it is, even for a new user. \$\endgroup\$ Nov 16, 2012 at 3:13
  • \$\begingroup\$ @SimpleCoder Hah! Yah but I agree. \$\endgroup\$
    – NickHalden
    Nov 16, 2012 at 3:20
  • \$\begingroup\$ he's new and cant post images! \$\endgroup\$ Nov 16, 2012 at 3:25

2 Answers 2


I see you do not have jumpers to join each side of the power rails. Note there is a gap on both sides down the middle for the Blue and Red outer rails.

Remember I said check power? That means you need an inexpensive multimeter to do this.

Best practice of using the breadboard is to use short solid wire leads and neatly connect flush to the board without large inductive loops. Keep IC's close toegether and imagine that it is a printed circtuit board layout. Add decoupling caps close to the IC. Avoid long jumper wires at all costs.

enter image description here

For fun here is a free tool to help design, layout and simulate. http://fritzing.org

I've never tried this before but looks ok.. Use staples for power and ground rails. Don't use wire with thick insulation. Try to get thin solid wire 24 AWG I believe. and lay down flat. enter image description here


Thanks for all your awnser, after studying a little bit into the RF module I found out my problem, the left side of both encoder and decoder are the Address PIN, which means they will only communicate if those addresses are the same, that was what I was making wrong, I left them all at 1 and changed the resistors in them both cause the TX need to have 20 times the resistence of the receiver, in other words 50k and 1M resistors.

All is working now, thanks to all.

  • \$\begingroup\$ So, you are saying, when you grounded all the pins on the left of HT12D and 12E, it worked? I'm working on a similar circuit. \$\endgroup\$
    – C--
    Oct 3, 2013 at 14:37

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