Let's Make Robots!

tank robot

line follow
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side_profile_base_platform_stack.jpg164.96 KB
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electronic_stack_connections.jpg134.12 KB
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finished_line_sensors.jpg109.93 KB
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Finished robot, on track.

I started with the same base as the Cocoabot http://letsmakerobots.com/node/36700 - I had not seen his, but great minds think alike. I built this as a demo bot for Roborave.org. I used aa Arduino pro328, with a proto shield jusrt for connections, and a protoboard on the top for my connections and two 2-motor H-bridge chips.

If you look at the track, you can see it is just black electrical tape. The original track - on the other side - has a tight turn the tracked base could not handle because it was too long.

The arm motor is to move an arm to dump ping-pong balls into a box. The front sensor determines the distance to the box. This is a QRD1114 IR LED and optotransistor.

The line followers are a Sharp GP2Y0D810Z0F. Thru a mixup, this sensor was meant to be the distance sensor. It is another IR LED/optotransitor, but with a filter that has a PWM-like output. I had to custom make a little PCB out of copper clad, JB weld the sensors onto them, then cut my own pads to solder the connections to. The "art" piece is my prototype connections to make sure I knew how to connect the thing.

Otherwise, construction was simple. I started with the electronics stack in the middle, but had to move it back to balance with the arm motor (a  kit by the same folks as the base).The same battery pack powered everything.

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Thanks for adding the video. It's always fun to see a robot in action.

I have a set of those treads and gearbox. Seeing your bot has got me wanting to dig out the parts and make a little tracked vehicle.

Is the cable ressy asked about the USB cable to the Arduino?

I hope you keep us updated on any progress like when you get your arm operational.

Thanks for posting.

BTW. I don't know if you noticed or not, you have several repeats in your photographs. "arm_motor_details", "first_placement_of_electronics" and "side_profile_base_platform_stack".

This is the first time posting to this site and first time uploading to youtube.

I know there are a couple of duplicate pictures, but the "delete" button action is obscure at best. I posted on an FAQ list on this site about adding pictures to the HTML - I inserted them, did a preview - looked good - then went back to edit and the pictures were gone.

If the wire you are talking about is a black/red twisted pair, it is probably power from the batteries. There is also a connector that goes to the side of the arm motor.

The arm motor was just for demo - I'm not planning on attaching an arm. The motor turning at the right time was the point.

In the video, I have the serial/USB cable plugged into the pro328 to first start the sequence, then read the various values, ie the line sensors, state machine transitions, etc. You can see me move it out of the way partway thru the sequence.

I hope these answer the various questions. This was a fun little project. I have a different one using servos and a PCB with the electronics (I made an Arduino pro328 clone). The PCB is the robot body.

I like your sturdy construction on top of the Tamiya stuff.  (After the gearbox they don't really leave you much space on the original chassis, do they?)

What's the wire (if it is a wire) coming in from the right?

The long wire is the USB/serial cable to start the sequence, then show the various sensor values and state machine transitions. I have a Command Line Interpreter (CLI) with commands that let me control various things - like read the line sensors in a loop, or set the thresholds, etc.

Hope that answers your question.

That's a good approach to know-- especially for debugging, I'll bet.  USB was one of my guesses... the other guess was a safety line, in case it made a sudden run for the edge of the table :)  Speaking of that, good thinking with the "T" at the end of the route.

I am happy to post the CLI code for Arduino if someone is interested. I do firmware for a living, and I have different ones for my professional work. The first thing I do is get a serial port working and port a CLI.

Please point me to the right FAQ or posting on the process if y'all are interested.

Looks cool but it's not really a robot (to some LMRians) without a video. I'd like to see your robot in action.

I hear black masking tape works better than electrical tape for line following robots. I know Parallax sold black masking tape but their site is down right now so I can't add a link.

Thanks for posting.

I added a video. The link is not showing - but at http://www.youtube.com/watch?v=d687tNFeaoY

I addedpictures in the HTML, but after a preview, they had disappeared. The pictures are in the attached files.