The 2.1mm panel mount barrel jack is used for power - solder power wires on prior to installation (large lug is positive). Drill a 1/2 inch hole just past the cover hole. The plastic dimple was chisled to fit it in that location. Thread the jack in securing with the included plastic screw ring. A large cable gland is used to run sensor/signal wires through the enclosure keeping things weathertight. Drill a 5/8 inch hole between the power jack and the other case cover hole. There is a small lip on the case - I dremeled it down a bit to have the gland fit snug.
Best to make mounting holes in the back of the case if needed to screw the case into the wall. This would probably be harder later in the build given the amount of items we are putting in.
The 1/4 Perma Proto is nearly perfect. The corners should be cut just a bit and the left hole expanded slightly to allow it to fit snug screwed on the left brass mounting hole. A small 8-32 screw is fitted on the left and I used an optional standoff through the right hole.
You can refer to the Fritzing diagram on the Overview Page for the parts placement.
I used two pieces of female header, 5 pins each, to mount the Trinket to the board. Single male pins are placed on the - line, the Trinket BAT+, and Trinket Pin 0 for connecting Bluefruit later although you can use hook-up wire if you like.
Four resistors provide the analog divider to multiplex three sensors. The 1500 ohm resistor (the large one in the pictures, your size is probably smaller, I used what was on hand) goes between the trinket 3.3 volt regulated pin to the common resistor junction. Each of the other resistors is connected to this common area and connected to Trinket Pin 3 (Analog pin 3). Four wires are run off-board to connect the sensors.
The black and red wires connect the power ground. The board is powered via a JST connector with attached wires that comes with the Adafruit LiPo charger board (near the top of the photos). The red wire goes to the Trinket BAT+ pin, the other to the pin labeled Gnd. Other parts of the circuit draw regulated power from the pin marked 3V (which is regulated by the Trinket to 3.3 volts and provides up to 150 milliamps).
The connector for the PIR (infrared sensor) is connected to regulated power also (bottom of pictures).
Double check your connections.
At this point it may be best to plug in the 5 volt power supply and charge the LiPo battery.
Wire the three sensor wires to a terminal strip for ease of connection. Below shows the bottom common (ground) connection, then the PIR switch wire (yellow), then magnetic sensor #2 and magnetic sensor #3 towards the top of the picture. You can solder wires instead or use a spring terminal block on the board itself although some of the wires may not fit well as the magnetic contacts have large stranded wires.
Insert the Trinket into the pins.
The PIR can be placed outside the enclosure but the nice clear case begged to inside mounting. There is enough clearance, but just. For best sensitivity, a round hole for the lens to come out (with some sealant) may be better.
The Bluefruit is connected to the circuit board as follows:
- BAT+ (line into Trinket) goes to Bluefruit Vin
- Ground (-) goes to Bluefruit GND
- Trinket Pin 0 goes to Bluefruit RX
Do a final test of the sensor function.
It is now ready to take the magnetic sensors off and perform the final install.