The name is a backronym really – ‘mFC’ sounded cool and figured it could mean Madox F@$@!%-up Contraption…or Madox Floating Camera.
Background / History
A work colleague who builds and competes with 1/144 scale model warships in the Australian Battle Group invited me to spectate at one of their nationals. Not having the patience to build a model ship, but not wanting to just turn up there empty handed twiddling my thumbs watching people play I figured maybe I can get something into the water too.
The idea was for a tele-operated floating camera that will film the model warships as they shoot each another to smithereens… only problem was the lack of time with the event looming in less than a month and work/personal commitments.
I usually design custom circuits/PCBs for my projects (one reason why some seem to stall for eternity). This time I figured I’ll learn from all my casual reading of Hack-A-Day and use commercial off the shelf products for this thing!
- Asus WL-520GU Wireless Router
- Denkovi USB 8 Channel Relay Board
- AV-Tech AVI202 IP Camera(aka TP Link TL-SC3000?)
- Johnson L450 Cartridge Bilge Pump
- 12V 7Ah SLA Battery
- 6V 3.2Ah SLA Battery 6AA NiMH Batteries
- $8AUD Waterproof Case from the discount store
- 2 × Stationary Trays
- Cable Ties
- Foam Blocks
- Terminal Strips
- Duct Tape
Concept of Execution
The WL-520GU will host an interface webpage to allow remote control via a laptop/portable device connected via WiFi. A CGI script will feed commands received via the web interface onto the relay board to control the thruster pumps.
The laptop/portable device will also be recording the live MPEG4 stream from the IP Camera from the WiFi.
Build was a bit rushed, it was the 4th June… the AusBG event was only 2 days away and I haven’t really started. Lucky it was all intended to be MacGyver’ed together anyway so 2 days should be plenty.
Too lazy to document properly the MacGyver Floating Cam (Name change?) so here’s an abbreviated process (warning : might not be in any sensible order since there was really almost no thought put into the process) :-
- Buy the stuff…yup…
- Compile/Install OpenWRT with libusb & libftdi onto the router.
- Confirm the relay board works with the router by manually running commands.
- Prepare a simple SSH script and Web GUI interface to drive the relay board.
- Beg someone (Richard K) to drill some holes in the lid of the waterproof case for me.
- Each of the bilge pumps were ‘roughly’ aligned and cable tied to the stationary trays.
- Foam blocks were cut to fit the stationary trays
- Pass through the pump wires through the lid of the water proof case.
- Cut some wire and strip the ends, wire up the contraption using screw terminals and the Wago terminal strips. WTF I have a wiring diagram here…6V SLA is now 6AA NiMH batteries.
- Duct tape, lots of duct tape. Painfully attach the stationary tray with bilge pumps by oneself to the waterproof case… use duct tape…lots of duct tape…even more duct tape…and more duct tape…such that the whole thing turns ‘black’ 🙂
- Try pack everything into the case…and pray that it fits…(it didn’t look like it would at first)…try harder….bend the wires…try harder…it’ll fit…IT FITS.
- Put in water for some testing
Rush build and just simple laziness means I didn’t bother much in terms of software and I probably suffered for it.
In writing this…in hindsight I’m too embarassed to show it 🙂 I’ll post it if anyone asks…but maybe just some photos for now…
I didn’t want this thing to fail spectacularly in front of so many people so its almost compulsory I do some tests…
Bath tub test 1 – http://www.madox.net/blog/2009/05/24/mfc-madox-floating-camera-part-1/
Bath tub test 2 – http://www.madox.net/blog/2009/06/05/mfc-madox-floating-camera-part-2/
Moment(s) of truth
- Moment 1 – Yay it floats
- Moment 2 – Crap it’s not balanced…forward lisps to the right…right lisps backwards….left lisps (forgot)… but backwards works!
- Moment 3 – Well at least the connection and the camera works…lets start recording…
- Works well enough on my laptop
- Works not so good on my friend’s laptop, drops connection every time i kneel down (the laptop is heavy)
- Works horribly on a WinMo phone…can’t seem to press the buttons on Opera and IE just looks horrible.
- Moment 4 – Argh the videos came out horribly 😛
Sample video :-
- The model warships are maneouverable enough to avoid the camera, don’t worry so much about getting in the way.
- Need way more speed to catch up to the action.
- Need speed control for better maneouverability, hard on/off motor control = near impossible to control.
- Need a streamlined hull(s). Moving a square block in water = neart impossible to control.
- Need a better control method… bought some playstation controllers for anything in the future 🙂
- Need a new laptop battery… 😛
Edit :- As requested by some people…