john abella | MakerBlock

DrawBot – Halp!!! No – seriously, a little help?

Okay, I’m stuck. I don’ t know what I’m doing wrong or what I need to do next. So, I’m calling upon John Abella, Sandy Noble, and Kongorilla for your help. :)

Here’s where I am:

The burning!

At last attempt, I hooked up some small steppers to the Adafruit motor shield, put the shield on my Arduino Uno, hooked up the USB cable and the 9v power adapter.
I heard a small pop and smelled warm electronics.1

After the burning

I can upload and run the Arduino basic blink sketch. I can alter this to change the blinking pattern.
I can upload and run the Arduino sketches to operate a microservo. I can alter this to change the microservo’s behavior.
I can upload the Adafruit sketches for steppers – but I can’t make the steppers move.
I can upload the Polargraph sketch – but I can’t make the steppers do anything.

I am connecting the steppers to the shield according to the instructions on the Adafruit page: “To connect to our shield, put the wires in this order: Red, Yellow, skip ground, Green, Brown“
When I connect the 9v power to the Arduino, all it does is make the two chips on the Adafruit motor shield very warm.

Now, I’ve got tons of questions for you:

Did I ruin my Arduino? I can still run the blink and microservo sketches.
Did I ruin my motor shield? How can I tell if it is operational? When I connect the power to the Arduino and have the little jumper in place, the green LED is lit up.
What am I doing wrong?
What should I try next?
How should I diagnose a problem?

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Now I’ve got a cold and couldn’t smell anything if I wanted [↩]

DrawBot – The Plan!

What’s next?

Well, once the parts arrive I’ll have my hands full. I’ll need to:

Solder up the Adafruit Motor Shield kit
Solder together some long wires to run between the motors and electronics
Print or recycle some spools1
Print the motor mounts and print-head/gondola
Add some monofilament line2

If the monofilament-spool system doesn’t work, I’ll switch to a ball-chain pulley system

Buy a long 1×1 wood board to which I can bolt all the parts
Put the parts together
Download some code
Hack some code
Upload some code
Draw, ‘bot, draw!

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Printing, for sure! [↩]
I don’t fish, but I have a bunch left over from a prior project [↩]

DrawBot – The Breakdown

The Breakdown:

Overall, this project cost to date is $103.30. That’s less than I would have spent for a single really large framed print. If I had to, I could have done this for less – especially if I were willing to be more patient.

If I had placed my order with just one source and for the cheapest/slowest shipping option possible, I might have saved $5 in shipping. 1 For the extra $5, I’d rather have all the parts arrive this Thursday rather than next Thursday or a month or two when the shields were back in stock.
I probably could have used an old power adapter from some other old scrap electronic device, but at $6.95 it just made sense to get a brand new device from Adafruit so I could dedicate the adapter to this project.
I could have probably done without the micro servo and saved $6.00 since I’m mainly interested in doing single-line drawings – but this small investment will ensure I can do any kind of drawing I want by enabling pen lifts.
I recently pulled two tin can stepper motors from old electronics, which could probably do the job. However, at $14.00/stepper motor the price just seemed right. These are pretty big motors that would be able to handle negotiating beaded cords with weights, if I ultimately have to go that route.
Since I don’t have tons of parts lying around and I’d like to get started on this project before the weekend, it was worth it to me to pay a little extra. However, if you just had to do this project for the cheapest possible amount and didn’t care how long it took, you could shop around to place a single order with one distributor, recycle a power adapter, and probably pull a small servo and two steppers out of some dumpster-score/junk heap.

At just a little over $100, I can use an identical hardware setup to John Abella – which means I can recycle his modifications to the Polargraph code. Since he was using metal beaded cord and printed gears, he had to modify the code to accommodate these changes. I’ll have to make some changes too – but it should be much easier to do so since I can compare John’s and Sandy’s code bases. If the parts ship today, I should be able to get them on or before Friday. The additional benefit of using the US Postal Service is that they’d deliver on Saturday if it comes to that.
For a full list of all parts I ordered, check out my post “DrawBot – Parts Ordered!!!“

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Adafruit was out of their motor shields, so I had to go to a third-party. Admittedly, a third-party I love using. Waiting until they were in stock and then placing a single order would probably have saved me $8, but the shield was already discounted $8 through MakerBot anyhow. I guess that would have been a wash… [↩]