Since the last post I’ve foxed the boat its trailer, been on holiday with the boat and done some more ROV stuf.
I have been concentrating on the YouTube channel and know wonder how many real people visit the website/ blog?
I would love to know if people were discouraged by by lack of update on the website. Which might make me spend more time on the webblog. Photos, videos etc……………
Finally got round to playing with the OpenROV control board. It looks like it will save lots of time.
Just had to set the fuse bits, upload the atmega 2560 bootloader, plug in the beagle bone black, apply power and connect a power switch and away she went 🙂
Command line string for setting fuse bits and installing the bootloader:
avrdude -c usbasp -p m2560 -P usb -b 115200 -e -u -U lock:w:0x3F:m -U efuse:w:0xFD:m -U lfuse:w:0xFF:m -U hfuse:w:0xDE:m
avrdude -c usbasp -p m2560 -P usb -b 115200 -V -U flash:w:mega2560boot.hex //(I changed the file name)
avrdude -c usbasp -p m2560 -P usb -b 115200 -U lock:w:0x0F:m
from:
http://cisana.net/burning-the-bootloader-onto-the-arduino-mega-2560/
and
https://github.com/OpenROV for the fuse bit settings
I am re inspired and hope to get the rov together in some form and through it in the water soon.
Checkout our youtube channel: mr Fishing Rov
FishingROV # videos 32-26.
I don’t know why I chose “mr fishing rov” as a YouTube channel title?
Lots of progress and learning has happened: plastics, endcaps, sensors, …… And a new workshop/cave for future videos.
Work has been a bit full-on so progress as been a bit slower than i would have liked.
I have ordered an OpenROV 2.7 control board which will hopefully save some time.
The idea behind the YouTube channel is moistly to spread the idea of fishingROV and hopefully generate some more interest. If you like the videos it would help a lot if you SHARE with your circles or like in YouTube.
First proper test of the chamber. And housing pressure test.
The housing will take 300 psi or 20 bar without implosion. Im not sure what the final pressure was because I didn’t have a data logging pressure sensor. But More than 200 metre should be plenty for the ROV.
I would still like to test- the cylindrical camera housing, floats, copper tubing and fittings…
And find a more reliable way of making the through hulls.
Just done the first test on the hyperbaric test chamber. Its looking promising still to: paint, attach high pressure pump and install lights, devise hold down rig for test item….
Assembled the five printprops.They are looking great.
And working on Buck converter for tether power. I am thinking about using the lm2596s with external fets- lots of things to learn. I might even make an Arduino shield to -logic shift for Beaglebone black, current sense, servo outputs and sensor connections…
Could a circuit like this work? Using a Switch Mode DCDC step down converter (48-24v) to 12v. Output from the transformer charge the whole bank, or individual sell groups. Effectively using the load as balancing resistors. FETS on the output of the transformer directly power the load or charge week groups. Low speed switching to maintain battery voltage????
Also laser cut ends for the hyperbaric test chamber arrived- I will try to stick them to the cylinder
this week. And do a few more videos squashing stuff.
Battery testing we have collected and tested 60+ cells. About 2/3 are ok and will store a reasonable amount of power. So we still need a few more to make the 45 cell pack.
Lovely box full of print-prop parts. First experiments with acetone vapour chamber I might have over cooked the first ones. 2 hours in the tub. Some wobbles in the print are still visible and the edges of the props are a bit rounded- I will give them a wee tweak when they have dried. Next ones will get a quick scrape with a knife to remove more wobbles before vapour chamber.
Really nice to see something real and a big part of the ROV. Thanks Andy and Ole.
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.
Planned construction of a hyperbaric test chamber. To test the ROV hull. It will pressurise to 40 bar or 400 metre equivalent depth. It will be interesting to see what happens when the pressure outside the ROV exceeds the gas compensated pressure inside and test the failure pressure of hull components.
The first pictures from inside the ROV. Some blue light noise from the LED on the camera reflecting of the inside of the dome.
The Microsoft lifecam hd 3000 720p worked without changing the openrov code.
I was a bit challenged when trying to write the openrov image to SD card from linux. The windows method worked great. I was also challenged trying to take a screen shot from linux- needed to apply changes to display settings to get one screen shot.
I am still playing with the networking. The first latency test on the camera range from 350-250 miliseconds- might be the screen capture, computer, network?
Pictured is the Arduino and project shield- left and the ACS712s for measuring the current to the ESCs- right. Behind is the new camera housing – 70 5 60mm acrylic tube 4 mm orings and a 8mm stainless connector so the housing can be opened without redoing the thread seal.
The OpenROV software looks great and will save loads of time. This project might turn into an OpenROV in a bigger box. Lots of very clever people have been working on it and that shows. Thank you.
I also made a battery discharger for testing old LIPO 18650s from defunct laptop packs. Inspired by:fixitsan on youtube. With arduino instead of PIC microprocessor.
Ben’s video about battery discharger:
