Wired Components
Let's take a moment to review the wiring in our components. We have three main components that required some soldering. The potentiometer switch will be wired in-line with the voltage wires from the DC jack and plug.
- Voltage from DC plug connects to DC jack
- Wire from DC jack connects to pot switch
- Wire from pot switch connects to DC jack
Install Crickit
The Circkit board has to be orientated in this specific way in order for all the components to properly fit inside the case. There's four standoffs built into the bottom cover that are designed for securing the Crickit PCB. Reference the photo and position the PCB over the standoffs. They're designed to fit M3 sized machine screws. Insert and fasten 4x M3 x 4mm screws to secure the PCB.
Install Motor Wires
The DC motor comes with pre-soldered male jumper wires and connect directly into the screw block terminals. It becomes difficult to install the motor wires once the case is installed so we can do it now. The positive wire goes to the far side of channel 1, while ground goes near the middle. Stick with channel 1 for this project but optionally can choose either. Use a small Phillips screwdriver to tighten the screw block terminals.
Installed Motor
Using screw block terminals in this build is nice and saves us the extra step of soldering. The CRICKIT uses a lot of screw block terminals because it makes swapping out components much easier. If we wanted to use a different motor, no need to unsolder/solder wires.
Install Potentiometer
Our first component to install into the case is the potentiometer. It's panel mounted to the side of the case, near the left corner. It's center with the height of the case and mounted to the far left using a washer and hex nut – these are included with the potentiometer.
Installed Potentiometer
Insert the shaft of the potentiometer through the hole and push it up against the wall until it's mounted. The threaded shaft should fit through the hole, use a filling tool if it's too tight. Install the washer and hex nut and fasten until fully tightened. I used the tip of my wire strippers to get a secure hold on the hex nut.
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Install DC Jack
Next up is the DC jack. Mounting this one is similar to the potentiometer, just insert from the outside, in. So the jumper wires will need to be threaded through the hole. The mounting hole for the DC jack is on the opposite side of the potentiometer.
Installing DC Jack
The body of the jack is threaded a hex nut can be fastened onto it. Press the jack so the flange is flush with the surface of the case. Insert the hex nut through the wires and twist to fasten it onto the body of the jack. I used my needle nose pliers to grib onto the hex nut and tighten. You may want to adjust the orientation of the jack to your liking.
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Install USB Panel Mount Cable
With the Crickit PCB embedded inside the case, the micro USB port isn't easily accessible. This USB cable is used to extend the microUSB connection so it's accessible on the side of the case. This is really handy for programming the Circuit Playground Express. It's just short enough to fit inside the case, along side the rest of the components.
Installing the USB Cable
The cable comes with two long machine screws used for panel mounting. Insert and fasten these into the two mounting holes on the side of the case – It's the two holes with the small rectangle between them. Install the screws so the tip just barely protrudes through the case. Then, fit the USB cable into the rectangle cutout. Line up the screws with the mounting holes and fasten until fully tightened.
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Install DC Plug
The right angled DC plug connects directly into the female DC barrel jack on the Crickit. The connector can be adjust by rotating the plug. It'll fit best inside the case when it's orientated like in the photo.
Install Bottom Cover
OK, now that we have all of the components installed in the case and bottom cover, it's time to bring them together. The case needs to be oriented correctly in order to properly install onto the bottom cover. Start by passing the motor through the case. Then pick up the case and orient it with the bottom cover referencing the photo. Slowly place the case over the bottom cover, moving wires out of the way. The two parts will "click" when pressed together. Be cautious of the wiring and make sure they don't get kinked or damaged while installing.
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Making Connections
With the two main assemblies now installed, we can make our connections and hook everything up. Since we employed jumper wires for most of the connections, it'll be easy to plug them up!
Wiring Power
I started with hooking up the DC jack to the DC plug and pot switch. These components provide power from the power supply to the Crickit. The voltage wire from the DC jack plugs into one of the jumper wires connected to the pot switch. The ground wire from the DC jack plugs into the ground wire connected to the DC plug. The voltage wire from the DC jack plugs into the remaining jumper wire connected to the pot switch. The pot switch is wired in-line with the voltage connection.
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Wired Power
Our circuit is now capable of receiving power. The connections here were a bit tricky to capture all in one photo because the depths of the wires vary. At this point, wire inspection ought to be conducted. A quick power on test also to see if the connections are solid.
Connect Potentiometer
The three jumper wires on the potentiometer will need to connect to the signal i/o pins on the Crickit. Use channel 1 and plug in the jumper wires in this order, going from left to right. Signal, voltage and ground. The connections are labeled PCB as well.
Connect USB
Let's get the microUSB stuff hooked up. The microUSB connector on the panel mount cable plugs into the Circuit Playground Express board, NOT the Crickit (thats one's for seesaw debugging).
Wired Connections
Just about finished with making the wired connections we can start to organize the wiring. Rearranging the wires so they can be tucked down into the case. This photo attempts to show all of the connections, before any organization. The extra slack in the wiring is intentional and should be able to be stuffed into the case without too much hassle.
