Due to the needlessly complex nature of my case, soldering and case mounting are somewhat intertwined, but I'll try to break it down so it makes sense.



I recommend that after each step you plug in and test the circuit to make sure you didn't make a mistake, moving each bit from the breadboard one at a time. Having to desolder components is no fun.



Tip: Use wires in as many colors as you can get so you can keep things straight. I also usually put labeled bits of tape on the ends of the wires to help me remember.



Tip: If you're using stranded core wire, be sure to tin the ends. It will help with your joints and make it easier to stick them into the breadboard for testing.



#1 Solder leads to the LEDs. (Hey, that almost rhymes!)

About 10" or so should work.



Okay, so much for the easy steps. After this it gets more complex because most of the components need to be threaded through various holes in our case before they're soldered. Of course if you made a different case then you don't need to worry about most of the tedium and can get right to soldering the components to the perfboard.



Tip: Mount the components as closely as possible to the perfboard. There isn't much clearance inside the pipe.



#2 Prepare the perfboard.

We're using a perfboard with 0.10" spacing where each hole has an individual copper pad. Cut the perf board to size (5x15 holes) and then sand/file/grind off some of the edges so it fits easily into the 1/2" PCV pipe.



For future reference we're calling the side with the copper "back" and the side with the components the "front".



#3: The ground line

Since the ground is the most common terminal in the project we're going to run a ground line across the back for the components to connect to. To make this I too a 9 inch piece of solid core wire that I'm using as my ground wire and stripped about an inch off one end. The soldered between hole 1 and hole 10 (see the attached diagram). Then I'll tack the other gronded components to it as the come through the board. (You can also just bridge the connections with solder, but I hate doing that because it can get messy. My soldering is messy enough.)



The other end of this wire will go to a Ground pin on the Arduino. (This is a good time to label the other end with a piece of tape.)



#4: The +5v line.

There are also a couple points where we want to supply +5v. This is the same idea as the ground line but we only need about half an inch stripped.



The other end of this will connect to the +5v pin on the Arduino.



#5: The LEDs.

Solder the LED's resistors (560 ohm by default) in place as shown.



You have two choices of how to deal with the LED's. You can mount them on top (the easy way) or you can mount them from the bottom, which looks better, but is a pain because 1/2" PVC doesn't give you much room to work. If you mount them from the top, be sure to thread the leads through the holes before soldering.



Thread all 4 leads from the leds out through the near end of the 'long arm' through the 5-way and through the 'board arm".



Solder the cathode (-) lead (the short one) from each LED as indicated. The anode will connect to digital pin 4 (red) and 5 (green) on the Arduino. (Thread the Ardunio leads through the "short arm" of the 5-way.)



#7: The knock sensor.

Solder the speaker's 1M ohm resistor in place on the board.



Make sure you have the speaker mounted firmly at the end of the spring and the wire is wound a few times around it to keep it out of the way. Thread the wire through the long leg, through the 5-way and into the short arm that we're keeping the circuit board.



Solder one end of these leads to each side of the 1M resistor. Then solder a 8" lead from the ungrounded end of the resistor. This will go to Analog pin 0.



#6: The button.

Solder the 10K ohm resistor in place as shown.



Fasten the button through the hole on the end plug, then put the plug on the 5-way connector and thread both wires through to the 'board arm' hole.



Solder one lead from the switch to the resistor. The other end to the +5v wire.



Solder a length of wire from the resistor according to the diagram and label it "Digital 2".



#8: The motor.

Nearly done.



Solder the diode, transistor and resistor in place. (Make sure you get the direction right on the diode. And the transistor for that matter.)



To the free end of the 2.2k ohm resistor solder a 8" lead that will go to digital pin 3.



Put the motor in place in the bottom hole of the 5-way connector, thread the leads trough and solder them in place on either side of the diode, making sure you've got the motor wires in the right order so when it runs it will turn to unlock.



#9: The Arduino pins

Connect the labeled wires to their appropriate places on the Arduino.



Test:

Wait, you don't need to do this, right? You've been testing as we go, haven't you?



Plug some power into the Arduino and make everything works. Especially make sure that the motor spins in the right direction to unlock your lock.





