The logic level converter arrived to connect the BeagleBone black to Arduino 3.3v – 5v 8 channel. OpenROV cockpit still not uploading firmware to arduino. Even Arduino IDE isn’t able to upload openrov.ino to the arduino mega. – avrdude: stk500v2_ timeout and getsync errors. I’m trying to upload from Linux so am struggling a bit with the learning curve.

Batteries are coming along. The discharger is working but we might need to add more cells to the pack as significant heat is generated while discharging at 2C or 4 amps.- 18650 from defunct laptop packs. I am thinking 45 cells- (15-15-15) 3S 15P which would mean discharging closer to 1C or 2.5 amps per cell when driving 2 thrusters on full power(480W or 40 amps at 12v) The £1 1A lithium charger modules from china have been setup with a desktop PSU and are charging 5 cells at a time for testing.

DCDC converters are a bit of the target of delivering 240w to ROV.

I just noticed the boos DCDC i got has a 8amp fuse on the input- so at 12v it will blow at 200w. Might use 2 of them is that’s possible. And the 18AWG wire that I got from China looks like its got about half the amount of copper it should- need to test to calculate what the final voltage drop will be.

I am also thinking about an array of 3 DCDC buck modules to be used as a charge controller individually charging each of the parallel cell groups from the teather input- This would  balance charge the pack and reduce the current output required from each buck module. Whether or not this is possible will become apparent. Much to learn.

 24v dc–>DCDC -48v———-teather———->DCDC—–>4.2v

                                                                                      DCDC—–>4.2v

                                                                                      DCDC—–>4.2v

I’m starting to think I might have had to learn less if I had just bought the OpenROV control board for $120. 

I would like to share the idea that fishingROV isn’t designed to replace trawling boats just replace the heavy gear that interfaces with the seabed. Could 10 mass produced fishingROVs directly replace heavy nets and be towed behind a fishing boat and catch a similar amount of fish? Obviously they would need to be autonomously catching the fish/scallops.

Given  the relative complexity of blowing an acrylic dome and the impact it has on the housing I am thinking about a separate main camera tube. Modeled on the openROV etube- clear acrylic tube with oring sealed HDPE-endcaps.

Floats are good- glass bubbles with hot glue- has the consistency of Plasticine when hot. It dosn’t sand very well but can be cut with a knife- and presumably could be melted with a heat gun/ blowtorch and resurfaced/shaped.

The tube with the orings in the tube seems to seal reliably at 150psi or 100m depth in water.

The endcaps could be made with a lath but i would like to keep it kitchen table tech if possible.

There is not much room on the endcap for the 1/4″ plumbing fitting so I will try 1/8″ fitting and maybe a 70mm tube?

Left trying the oring in a groove in the outside piece of endcap- the oring keped popping out while under pressure. Right oring in a groove in the internal piece of endcap- tested to 230psi then the pump started to leak. A washer on top of the endcap and tightening the rod stopped the endcap leaking. I was expecting the acrylic to fail.

I will also try the dome as camera housing to see if the additional work is justified by the greater viewing angles and less lateral distortion on the image.