Archive for the ‘electronics’ Category

Focused workshop: Artbots 30 May 10 — PNCA ($35)

Saturday, May 22nd, 2010

In this workshop we will be taking our dorkboards and using them to create a simple machine that draws. The focus will be on hands on problem solving.

What you will get.

  • A servo and a geared motor with paper feed.
  • A motor driver board.
  • Misc parts.

What to bring:

  • A dorkboard, teensy or other arduino capable board.
  • A soldering iron.
  • Some basic tools (esp wire cutters, x-acto knife)
  • superglue
  • A hot glue gun.
  • foamcore or cardboard.
  • $35 or a copy of your rsvp / paypal reciept.


PNCA — 1432 NW Johnson St, Room 205

Sunday May 30nd from 1 to 5pm

How do I rsvp?

Making Pigs Fly — Object Space, Spokane 07-11 June 2010 ($105)

Sunday, May 16th, 2010

An introduction to physical computing for artists and musicians.


This workshop is an opportunity for 15 to 25 people to spend a week working on the fundamentals of integrating micro-controllers into the arts. At the end of the week participants should be able to build and program their own Arduino compatible micro-controller system and use it to interact with the physical world using motors servos lights relays and switches.

The workshop will be structured with a hands on approach. The theory being that we learn best by doing. The first two days will be devoted to building and programming the base platform and using it to control various devices. The remaining 3 days will be a lab devoted to incorporating the new tools into actual pieces. The cost of the course is $105 and includes the materials listed below as well as 5 days of hands on instruction.

What you will get.

  • A Benito usb to serial programmer
  • A Dorkboard! (an Arduino clone) Kit
  • An introduction to the Arduino and microcontrollers in an artists setting
  • A servo and a geared motor with paper feed.
  • A motor driver board.
  • Misc parts.
  • Help when you need it
  • To know that what you built worked at least once
  • Ideas

What to bring:

  • A laptop (there will be some (not many) loaner systems available)
  • A soldering iron (20-30W Pencil type)
  • A standard usb cable (A->B)
  • Some basic tools (esp wire cutters, x-acto knife)
  • superglue
  • A hot glue gun.
  • foamcore or cardboard.
  • A copy of your rsvp / paypal reciept.
  • Ideas.


June 7th through June 11th from 1-5pm.


Object Space Gallery:

1818 1/2 E Sprague, Spokane WA

How do I rsvp?

My Sample Design for Fabrication Workshop.

Tuesday, December 1st, 2009

At the eagle for fabrication workshop on sunday I started with a design that Thomas Lockney threatened to build about 2 years ago called the Low Fi Arduino Guitar Pedal.


It was simple enough to get through the necessary parts of eagle that I was teaching and while it wasn’t perfect It beat the hell out of Craig Anderton’s circuits in terms of clarity and probability of actually working. To discuss from an over view perspective creating parts I decided to add the 1/4″ jacks from another great dorkbotpdx project from Hans Lindauer.

Once I got the library part together for the 1/4″ jack I had to rearrange things quite a bit but there was still pleanty of room. The next step was to add a power connector and a regulator. The idea is to be able to mount the resulting board in one of the cheapo danelectro pedels that I have around like this

In order to get the board to work out I had to create a new package for the potentiometers but I managed to get it all to fit on the board without resorting to surface mount components.

I will post the library example latere this evening.

3 ways to 3 volts

Wednesday, January 21st, 2009

I have a few devices that I need to interface to either the benito or another avr board that run at 3.3v. one is an ethernet interface, one is a bluetooth modem and then there are the x-bees.

One Way: Simple Voltage Divider.

When looking for interface examples for the xbee I found a site that started out with a circuit from maxstream and then once everything was working tried a resistor based voltage divider. This is how I got my first set of x-bees running via the ftdi chips.

One thing that this circuit didn’t do for me was to provide a decent pull-down for the reset. The 2 transistors on the right of this circuit are an attempt to do just that.

Another Way: Run everything at 3.3v

If you look at the datasheet for the atmega168 you will find the following diagram.

Looking at this you can see that 16mhz may or may not be in the operating range at 3.3v. But if you drop the crystal down to 8mhz you are good for sure. You may have to change a few things but it is doable.

The Ever Illusive Third: Buffers.

The idea of adding another layer at each interface between boards can have you asking for some Tzatziki and falafel to go with the PITA. There are buffers which are designed specifically for this. Many of the odd, many of them expensive. But there are also many families of buffer which are “tolerant” of a range of voltages outside of their supply. One of the buffers I checked out was the 74abt126 which is a tri state buffer. (I was looking at that because with the tristate buffers you can actually do a two way buffer by selecting the direction). I am not entirely certain that the 5v receive side is kosher with these.

The other buffers I am looking at with 5v tolerant i/o are the 74lvc125 and 74lvc126. These are 3.6v native parts with 5v “tolerant” io.

Since I ordered the wrong series of parts last group order I will have to wait a week to check this out.

See Also.

Practice 1, Theory 1

Tuesday, December 30th, 2008

As part of getting the new workspace space I moved the toxins related to casting and circuit board fabrication out of my apartment. The theory being that the space is semi industrial.

So as a test of the new space I took one of Alex Normans board designs and etched it.

Since the last time I worked with Alex on his designs he has picked up quite a bit and I only spent about 10 minutes getting his eagle files layed out and printed before going to the office. When I got there I realized that I had forgotten the green trf and bon ami but we were still able to get a reasonable etch and the new space has been broken in on the practice side.

One Step Beyond ! Taking your boards to the shop.

Wednesday, August 15th, 2007

Two months ago fellow PARTs person and DorkbotPDXer Mark Gross gave me a $100 gift certificate from Sunstone Circuits from last years PDXBot. Sunstone circuits is a local (oregon) board fabrication company who makes a windows based design to board solution called pcb123.  Since i am Mac based I had been putting off the board design until the last possible minute. I had several ideas which I have been laying out and fabbing by hand and a lot of other things on my plate. I had planned to select a design and work on the boards the week of after the arduno cult indoctrination but after spending the weekend frantically building 27 ftdi based boards and then finding that the design in process needed to be simplified if it was to be unleased on the general public. I instead focused on learning cocoa and leaving any new hardware design on the backburner.  I did spend a few hours redesigning my ftdi based boards and then used that work to make a single purpose board based on the benito 5 programmer that I built and have been developing with monty goodson of bittybot.