BUILDING THE JN3
Make sure that you have all the parts needed, see the JN3 Specs and this overview:
Here is a step-by-step overview of putting all the components on the JN3 board:
http://news.jeelabs.org/2009/07/15/building-the-jeenode-v3/
Connect a 1/4-wavelength wire antenna to pin 1 of the radio module:
for 433 MHz, use a 165 mm wire
for 868 MHz, use a 82 mm wire
for 915 MHz, use a 78 mm wire
That's it - you're done, but keep the following in mind before moving on to JN3 Tips !
IMPORTANT ISSUES FOR JN3
Be sure to mount the MCP1702 voltage regulator the right way around:
Double-check using the schematic and board design files on the JN3 page.
The following choice is now the preferred way to solder the header pins on:
http://news.jeelabs.org/2009/07/08/plug-pinout/