Part 5: The Build
Ready to commit this to a board. I decided to go with a RadioShack PCB:
I know the community is not fond of RadioShack, but they are getting better and this little board gives me the flexibility and connections I need to fit the project. Plus, it sits nicely in my SparkFun project case — with some slight modifications. I particularly like how the power and ground traces are available all around the board.
A couple of minutes (did I say minutes? I meant HOURS — my soldering skills are rusty) on the project bench and I came up with this:
Critical step here, TEST, TEST, TEST.
First test (and the simplest): make sure that power and ground are not connected. Use a multimeter and test for continuity. You only have to join these together accidentally ONCE to learn your lesson and never do it again. I’m hoping you learn from my mistakes. There are so many ways for this to happen: mistake in the circuit, extra drop of solder rolling somewhere it shouldn’t, a clipped off lead getting wedged between two adjacent leads.
Next test, I plugged it back into my breadboard to give power and make sure the basic connectivity is in place before attaching the socket/regulator.
The eagle-eyed among you will notice that I added two LEDs to the circuit. One is just a power LED — if the circuit has power, this LED is on. The other is an “ad hoc wifi” indicator. Pin 8 gets tied to power to put the WiFly in ad hoc mode. Thought it would be a good idea to make this an external push button (push on/push off) switch instead of having to open the case if I need to activate ad hoc mode.
A few more minutes (did I say minutes?…) and the finished circuit is ready.
The other great thing about the regulator… It acts like a socket so if I need to swap the WiFly, it’s easy.