Fletchtronics

Hope you like the new design.

On an unrelated note, here's a bunch of Bumble-Bs for you!

A Bunch of Bumble-Bs

Bumble-B version 2.0 is coming soon to fletchtronics.net. There have been several improvements.

• Updated microcontroller: ATMega32U2
• 3 pin power header replaced by a switch
• Improved silkscreen
• USB D+, D- lines now accessible
• 100% RoHS

The new microcontroller ATMega32U2 is pin and firmware compatible with the chip it is replacing, the old AT90USB162. You can flash an image made for the 162 on to the 32u2.

On the train on my way to work yesterday morning I was hit with an inspiration on how to build something like the hotpot and softpot potentiometers that sparkfun.com sells. Only, I wanted something that cost a bit less than $19. See? Commuting really is good for something!

Remembering back to my days as a troublemaking youngster, I recalled that putting 12 volts across the lead of a pencil caused it to glow brightly red (and then stink up the basement). So I knew that it would conduct and that it has resistance.

So I wondered if something as simple as pencil on paper could be used as a resistor. As it turns out, yes, yes it can.

Inside LUFA is a neat project called AVRISP. With this code, your BumbleB becomes a programmer for other AVRs. The project can be found in ./Projects/AVRISP. With a few changes we can use this code and BumbleB to program other AVRs and even other Bumble-Bs.

Bumble-B AVRISP -> ATMega168 Example

When building devices with USB capable microcontrollers, a quick and simple option for communicating with a host PC is to use CDC, a virtual serial port. This handy mechanism is built into all modern PC operating systems. However, the way you open a serial port, set line settings, and start speaking serial are very different between Microsoft Windows and POSIX based platforms. This library and program bridges the differences between the two APIs and supplies a console tool for making communication in scripts much simpler.