Instructions for hardware construction for FishOASIS camera.
Battery Pack
In-Line Connector
Ikelite Housing
Modifications to Electronics
Click here to download the original parts list for FishOASIS camera.
Click here to download an updated parts list (03/11/2021).
Cut the PVC pipe into a 30-inch long tube using a hacksaw or a PVC pipe cutter.
Prime each end of the cut pipe. On one end, glue the PVC cap using the cement. On the other end, glue the union connector. A tutorial on how to prime and glue a PVC pipe can be found here.
Once glued, your PVC tube with end cap and union connector should look like this:
Using a benchtop drill press, drill a 25/64 hole into the center of the acrylic disk. Then, run a 7/16-20 tap through the pre-drilled hole. A tutorial on how to drill and tap a hole using a benchtop drill press can be found here.
Grease the O-ring on the bulkhead connector using a silicone-based grease and screw the bulkhead connector into place as tight as possible. The acrylic disk with bulkhead connector should look like this:
More information about the bulkhead connector can be found here.
Strip the ends of the four wires attached to the bulkhead connector. Crimp a power connector pin (i.e., male end) to each of the four wires.
Insert the crimped wires into the female end of the 6-pin Molex connector using the following pin layout. Note, the wires on the bulkhead connector are labeled with numbers and correspond to the numbering used below.
A tutorial on how to crimp the power connector to the wires and how to install a Molex connector can be found here. A short video can be found here as well.
To build the 720 Wh battery pack, you will need to solder wires together and cover the connections with heat shrink tubing. Here are a few tutorials on how to work with wires (including stripping, splicing, etc.), how to solder and how to use heat shrink tubing. Here is also a brief tutorial on working with batteries.
First, connect 4 battery holders (i.e., 12 D cells) in series by soldering the positive end of one battery holder to the negative end of another (i.e., red to black wire). Cover these connections with heat shrink tubing. Repeat this an additional 3 times. Secure adjacent battery holders with small zip ties.
Stack two lines of 4 battery holders as shown below:
Connect the two lines with small screws and washers through the small openings at the end of each battery holders as shown above.
Place the two stacks (i.e., two lines of 4 battery holders stacked vertically) side-by-side and tape them together as follows:
Your battery pack should now look like this:
On one end of the battery pack, solder and heat shrink together the two negative (i.e., black) wires with a third 20 AWG black wire that is long enough to reach the other end of the battery pack. Repeat this for the positive (i.e., red) wires. This combines two lines of battery holders (i.e., 2 x 12 D cells) in parallel.
At the other end of the battery pack, solder and heat shrink together the two negatives (i.e., black) wires from the battery holders, the third 20 AWG long black wire from the opposite end of the battery pack and two additional 20 AWG black wires at least 12 inches long. This will connect all four lines of battery holders (i.e., 4 x 12 D cells) in parallel and will provide two outputs to be connected to two step-down converters, respectively. Repeat this for the positive (i.e., red) wires.
Pair one of the black wires with one of the red wires. These two pairs of wires will be the input into two step-down converters. Solder the black wire from the battery pack to the IN - input of the step-down converter. Solder the corresponding red wire from the battery pack to the IN + input of the step-down converter.
Solder a red wire to the OUT + output of the step-down converter. Solder a black wire to the OUT - output of the step-down converter. Crimp a power connector sleeve (i.e., female end) to the other end of these wires.
Set the voltage of one step-down converter to 5.2 V. Here is a short video on how to adjust the voltage of the step-down converter. Insert the red crimped wire into position 3 of the male end of the 6-pin Molex connector and the black crimped wire into position 4 using the following pin layout. This is to power the Raspberry Pi single-board computer.
Repeat the last two steps above for the second step-down converter. However, this time, set the voltage of the step-down converter to 7.9 V. Insert the red crimped wire into position 1 and the black crimped wire into position 2 of the male end of the 6-pin Molex connector. This is to power the Sony alpha 7s ii camera.
To test the wiring of the battery pack, fill one line of 4 battery holders with 12 D cells. The lights on both step-down converters should be illuminated as shown below. You can measure the output voltage from each step-down converter with a multimeter to confirm that they are 5.2 V and 7.9 V, respectively. Repeat this for all four lines of battery holders individually.
Cut an 8-inch long clear PETG tube and drill two holes into the tube:
Thread a female locking sleeve onto each micro in-line connector. Thread the cut clear PETG tube onto one of the micro in-line connector.
Solder the four wires of the micro in-line connectors together based on color (i.e., white to white, green to green, etc.) and cover the soldered wires with heat shrink tubing. Move the clear PETG tube over the heat shrink tubing and tape the ends of the clear PETG tube to the micro in-line connector.
Check for electrical continuity between the connections.
Pour the cable insulating resin flame retardant (also known as scotchcast) into the clear PETG tube. Here is a tutorial on how to use resin. The resin will waterproof this connection between the micro in-line connectors. Cover the in-line connector with abrasion-resistant expandable sleeving, covering the ends with electrical tape to keep the sleeving in place.
Check again for electrical continuity between the connections.
One end of the in-line connector will be the connection to the battery pack while the other end will be the connection to the Ikelite housing. Before connecting the female in-line connector to the male bulkhead connector, add Molykote to the female in-line connector.
Using a benchtop drill press, drill a 25/64 hole into the flat top of the Ikelite Housing. Then, run a 7/16-20 tap through the pre-drilled hole. Grease the O-ring on the bulkhead connector using a silicone-based grease and screw the bulkhead connector into place as tight as possible.
Strip the ends of the four wires attached to the bulkhead connector. Crimp a power connector pins (i.e., male end) to wires 1 and 2. Insert the crimped wires into the female end of the 2-pin Molex connector using the following pin layout. Note, the wires on the bulkhead connector are labeled with numbers and correspond to the numbering used below.
Cut and remove the USB end of the USB/micro USB right angle cable. Solder the red wire of the micro USB right angle cable to wire 3 of the bulkhead connector. Solder the black wire of the micro USB right angle cable to wire 4 of the bulkhead connector. Cover these connections with heat shrink tubbing.
Remove the foam backing from the back plate of the Ikelite housing.
Unscrew the camera tray from inside the Ikelite housing. Cut a 1-inch by 0.5-inch rectangle into the first two, thick plastic layers of the camera tray in the bottom, right corner using a hand saw. This creates an opening to allow the wires from the camera battery to be connected to the Molex connector from the bulkhead connector.
To secure the miniature speaker, add a small piece of velcro to the right side of the Ikelite housing. Remember to also put a small piece of velcro on the back of the mini speaker itself.
Cut and remove the end of the dummy battery as shown below:
Crimp a power connector sleeve (i.e., female end) to each wire. Insert the red crimped wire into position 1 of the male end of the 2-pin Molex connector and the black crimped wire into position 2 using the following pin layout.
Remove plastic tab from camera battery door to make room for the battery output wire.
Screw the plastic camera mount from the Ikelite housing onto the bottom of the camera.
Solder one wire of the miniature speaker to GPIO Pin 3 (i.e., 8th pin down on the left) on the underside of the RPi. Solder the other wire of the miniature speaker to the ground pin (i.e., 3rd pin down on the right) on the underside of the RPi.
Here is a guide to the GPIO pins for the Raspberry Pi A+.
Camille Pagniello ([email protected])
Last Modification: 01/07/2020