Fish Tank

ignoblegnome · February 15, 2012, 2:25pm

Videos:

Introducing FishTank
FishTank Update
Fish Tank Meets Piranha Tank

Code:

ver 0.3 is the basic code with obstacle avoidance and IR following
ver 0.4 adds some logic to help when stuck in a corner experiening quick repetitive turns, backing up if too close, and general cleanup

Update 2012-09-20: Nemesis!

Fish Tank is pursued by his nemesis, Piranha Tank!

Update 2012-09-06: Fish Tank finally has some fish food.

I made a couple of little IR beacons built into little plastic fish toys. They have a 3V coin cell battery powering a Radio Shack High-Output Infrared LED (part # 276-0143). A small resistor limits current to the LED. The beacon is turned on when it is placed on the floor and the lead of the resistor contacts the battery.

There's a small neodymium magnet hot glued to the top of each fish, and Fish Tank has a slightly larger but less powerful disk magnet glued to the underside of his IR fish finder.

When Fish Tank drives near one of the beacons, it manuvers into postion and runs straight over the little fish. The neodymium magnet is strong enough to pull the little fish right up to Fish Tank's own magnet. Lunch is served.

Update 2012-08-28: It's a whole new ball game... light finding Fish Tank!

I made a very fun modificaiton to Fish Tank's hardware and programming. Now he can follow light and IR.

I added a DIY Infrared sensor, based on this excellent post on making your own IR obstacle detector by OddBot. I used essentailly the same circuit, with slightly different components.

Of course, my circuit does not include the IR LEDs, because those will be located on separate beacons.

I drilled two holes at the front of the tank's upper deck, which allowed me to neatly mount the new IR sensor with a couple of cable ties. The position of the sensor has the unexpected benefit of helping to keep the battery pack from sliding out of place, which is an issue I ran into. Happy accidents are fun!

The code is still in progress, but version 0.3 is attached, which includes the new behavior.

I learned a lot from OddBot's post on making your own IR sensor.

I'm using essentially two copies of the right side of this schematic in my IR sensor for Fish Tank.

In my version I use the bc337 transistor, just like in the SpurtBot circuit. The IR transistor I'm using are the ones from the Radio Shack Infrared Emitter and Detector pair (part # 276-0142).

For Fish Tank's beacons, I wanted a stronger IR emitter than what came in the pair, so I used Radio Shack # 276-0143 High-Output Infrared LEDs.

Update 2012-08-25: Finally added the fish and so this project has been renamed. I'm bringing this guy to Maker Faire.

I'd like to make some little IR beacons that look like tiny fish, and have Fish Tank try to 'eat' them. Maybe also a different IR 'big fish' beacon that someone can wear. Then Fish Tank can run from big fish.

Note: I have posted a review of PropellerHeadGeek's kits on LMR and on my blog.

Good at climbing.

Side view.

Here's lookin' at you, kid.

Drives slowly and nearly unstoppably looking for infrared fish to eat.

Actuators / output devices: Tamiya twin gearbox
CPU: Picaxe 28x1
Power source: 3xAA NiZn 1.6V
Sensors / input devices: Infrared Bowtie
Target environment: indoor

This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/fish-tank

targetdg15 · February 15, 2012, 3:13pm

nice!!

Have any plans in the works for it?

ignoblegnome · February 15, 2012, 3:42pm

I’ll add some more detail

I’ll add some more detail soon.

I was thinking about adding some bright blue LEDs, but other than that I’m looking for inspiration.

Maybe something silly, like this.

targetdg15 · February 15, 2012, 3:46pm

!

That would be beyond epic

pauljd · February 16, 2012, 8:44am

Tracks

Hi IG,

I know you’ve talked before about the ratio’s of track size to distance, etc. and, just visually, it seems like you’ve nailed it on this bot. - they just look right! can you tell us the dimensions and ratio’s you used to get this design?

thanks, Paul

ignoblegnome · February 16, 2012, 9:51am

Firstly, all credit for the

Firstly, all credit for the design goes to propellerheadgeek, not to me!

Here are some of the dimentions.

Wheel base (length of road wheels from axle to axle): 72mm
Track (width from center of tread to center of tread along the axle): 90mm

So you see that even though the robot body is fairly long, the actual track in contact with the ground is shorter front to back than it is side to side.

ignoblegnome · February 16, 2012, 2:19pm

We’re going to do this!

Ridiculously crude mock up of the ‘Fish Tank’.

ignoblegnome · February 16, 2012, 2:55pm

So is the above picture

So is the above picture better, or something like this?

I like the way the color scheme lines up here. The tail is motorized and can be made to swish back and forth. I'd mount the whole fish on a servo and embed the Sharp IR sensor in the fish. So turning the fish allows the tank to look left and right for obstacle avoidance.

ignoblegnome · February 16, 2012, 8:56pm

I am commenting on my own

I am commenting on my own robot, mostly so I don’t forget these ideas. It’s like a blog/robot page thing. Whatever.

The Fish Tank totally needs to be able to play music and dance to it. Like a one fish homage to the Sashimi Tabernacle Choir.

roboticsmaster · August 29, 2012, 5:43pm

exquisite design!

That’s a unique concept using an old toy and turning it into an awesome fish tank! (lol) It would be even more intersting if somehow you could put a water tight coating around the chassis, and then you could put it in shallow water to make it look like its moving on top of the water!

ignoblegnome · August 29, 2012, 8:41pm

Ha ha. That’d be pretty

Ha ha. That’d be pretty cool, but this chassis will never be water proof. The fish toy originally was, but it’ll never be the same since I hacked it. ; j

Thanks for the complements. I’m glad you like it.

jorgen · September 7, 2012, 5:15am

Well it seemed to turn out

Well it seemed to turn out pretty close to design specs!

love it

merser · September 7, 2012, 5:33am

Nice play on words

That is the happiest looking fish I have ever seen. The orange Tamiya wheels are almost colour matched too. Crazy but sweet.

antoniocaciuc · September 7, 2012, 7:49am

How 'bout something like this:

http://www.youtube.com/watch?v=VB1nfDBDMdU

kariloy · September 7, 2012, 10:12am

Awesome

Now… just let me get my own gold fish… and pimp up a nice ride for it

ignoblegnome · September 7, 2012, 11:53am

Thanks, guys!

Thanks, guys!

mikv · September 23, 2012, 6:15am

Fish tank! that is precious,

Fish tank! that is precious, i laughed hard at that one, nice ignoblegnome =D

grimer · December 26, 2013, 8:19pm

Hello, I know this is a

Hello, I know this is a kinda old post but, I dont think it hurts to ask, im makig a robot with the same tamiya tracks configuration, and i plan on using wood to make a wooden platform instead of using the tamiya universal, and im looking for informations about the spacing of the wheel holes in the platform you are using, if that is possible, thank you.