Pdxbot.07 recap and my 3 day drawing arm.

Posted by & filed under Dorkbot.

There is something perverse about creating an event and then winning it.
It seems as thought Thomas, Jason, and I along with a few other dorks put in more hours in meetings, creating art and preparing for pdxbot.07 than pretty much any of our personal projects let alone anything that we could have brought to it.

And what have you done for the revolution today?

Posted by & filed under Dorkbot.

Its one am and though i studied and built circuit diagrams and layed out the parts and I went to work and communicated and wrote and coded but no arms have moved and while joints have been soldered no sound or movement has come out.

In the morning the list of shit I havent gotten done goes on.

Sorry emilliano.
/me sings in my worthless spanish

“Yo dice nada nada nada

manyana en la manyana

nada nada nada hoy!”

But what if it dont work?

Posted by & filed under Dorkbot.

A couple of weeks ago I took one of the projects that came to the meetings last year using the arduino called the bzztbomb. I am trying to take this Arduino project to the next level in two ways.

# to create a board which would cleanly amplify the sound from the arduino board as an above board add on.
# To create a low cost board which could be used to for the finished product.

The schematic for the V-1 in its current form is at http://www.digithink.com/embedded/hardware/arduinosound/rev1/noisinout_reva.pdf
The eagle files are at

http://www.digithink.com/embedded/hardware/arduinosound/rev1/noisinoutdip_a.sch
and
http://www.digithink.com/embedded/hardware/arduinosound/rev1/noisinoutdip_a.brd

http://dorkbotpdx.org/files/images/postapril.preview.jpg

When I finished my prototype I was able to get stereo output by modifying the example sketchbook called play_melody_faded_volume but found that the sound out of the pwm volume control sounded aweful.

I started looking at filtering the output to get smooth outputs. One of the missing pieces of the documentation of the arduino AnalogWrite is the duty cycle of the timer. A web search had the timer running at everything from 400 hz to 10-32khz. Once I finally put the sketch on a scope I found that the pwm duty cycle is 2ms long.

500hz.

The sound being modulated is in the range between 261(c) and 523(C) hz. which makes 500hz a very unuseful value.

In otherwords the model included in the examples doesdnt work with ardueno – 0007.