I went through the Arduino Cult Induction on Sunday and had a good time (once I got to the correct address). I was so happy, I went to Surplus Gizmos and bought another Dorkboard to play with. However, the microcontroller (Mega8) I bought didn't have the bootloader installed. So I tried to use my working Dorkboard to burn the bootloader onto the new Dorkboard. It didn't work. I got a verification error on the first byte.

I was adapting the instructions here: http://arduino.cc/en/Tutorial/ArduinoISP

Anybody have some helpful tips or suggestions?

At the last Monday meeting I picked up a gyro/accelerometer kit from Paul. This is a successor to his accelerometer board which several of us have built successfully. This new board is a more complex build, both because it has two LGA packaged sensors and also because it is pretty tightly packed and almost all of the discrete components are 0603 0402 (I thought they looked small....) packages. I used a couple of single package solder paste stencils (LGA 12 and LGA 16) to put paste down for the two sensor chips and put paste on by hand for everything else.

Daniel and I have been experimenting connecting Txtzyme applications up to his newly acquired PlugComputer. Monday we demonstrated a cascade of signaling protocols to implement a beer bottle sensor.

The flow (of information, not beer) is as follows:

• PlugComputer sends Txtzyme program over USB
• Teensy interprets program, sends pulse request to sensor
• Parallax sensor, emits ultrasound, responds with PWM measurement
• Teensy translates pulse width to echo time, an ASCII integer
• PlugComputer relays echo time over SSH to display
• Javascope plots echo history, showing beer movement

Next scheduled induction is 29August !!!!

Build your own Dorkboard!

From Parts...

To Programmed Micro Controller

What:

http://www.dorkbotpdx.org/workshop/arduino/cult_induction_rev8

Next scheduled induction is in 2011.

Parallax's nifty little sonar uses a single signal line to both trigger a measurement and return a result. The result comes back as a variable width pulse from which one can determine the round trip transit time and from that distance to the acoustic reflector.

I used existing Txtzyme tools to study this behavior and then improved Txtzyme to simplify this sort of measurement. I used the Javascope viewer from an earlier project to capture images of the return pulse that looked like this:

Paul told me it was difficult, but not impossible, to make an AVR USB bootloader that fits in 512 256 words of Flash (coincidentally, the size of the smallest configurable boot block on most of the USB-enabled AVR chips). So of course I had to try. But along the way, I needed an AVR serial programmer (to burn the boot block) but I didn't have one. However, I did have the broken Teensy Paul gave me (which had a few spare GPIOs after the Avago Yow! project) and Ward has been showing off his Txtzyme interpreter, so...

Well, I stumbled on this group on a link from Hackaday. There isn't much to say right now, other than "Hi", and do check out my start on a Wiki.

The HDLx-2416 is a neat little four-character ASCII display that just happens to fit, pin-for-pin, on top of a Teensy as if the Teensy were made for it. I snagged one from the DorkbotPDX spare parts bin after Dave showed me now neatly his Yow! project fit together. Of course, while testing the limits of Txtzyme, I had to put a Yow clone together.