Dead in the Water

Our engine failed this afternoon coming out of Manchester harbor; good practice anchoring in a hurry. After some diagnostic work we discovered these parts inside the fuel bladder had popped out of place and blocked the gas flow.

Signal Generator Circuit with Volume Control

This is the prototype circuit using the XR-2206 signal generation IC. D3 extracted a Toshiba TC9235P volume control IC out of a small Cambridge SoundWorks desktop radio found at a yard sale; the up/down control (silver knob) is out of a CD player. The XR-2206 has a pin dedicated as an amplitude modulation input and early testing shows it works very well. For use testing our amplifiers, filters and enclosure designs, we plan to build this into a portable instrument box.

Mayapple Flower in our Shade Garden

A photo of a Mayapple flower growing in our shade garden. These plants were transplanted from my grandfather's house; this was the topic of his last research project. The article published in the American Journal of Botany can be found by clicking on the title of this post.

Push Button Circuit Schematic

This is the circuit D3 designed for the new push button shown in the earlier post. It provides logic and timing for the blue blinking sequence (earlier video) and control lines for indicating charging (red solid) and errors (blinking red).

Push Button Switch

This is a new switch with blue and red led lighting that just arrived. D3 built a circuit to blink with a slow-on slow-off pulsing mode as seen in this video. This will be used to turn our speaker systems on/off. Working today on new functionality, the circuit design now has a start-up sequence that blinks 5 times when the button is pressed and then stays on. It also has a control line that turns the color to red and blinking that will be used as an error or out-of-range condition indicator.

Power Supply Failure

Not every supply works as we would like.....

Air Deflection Fin Design

Improved fin design for seagull whacker.

Seagull Whacker

One end of the frame to support a dual seagull-whacker.

Mother's Day Kite Surfing

A real treat to see an Olympic caliber kite surfer fly by just a few feet away. A full sequence of photos from this run can be found by clicking on the title of this post (then click on slide show button upper right).

BS2P

We recently upgraded to a BS2P Stamp microcontroller with support for I2C and seven segment displays. In this photo, D3 wrote code to write and read-back from an I2C eprom on the breadboard and display the results on a LCD display scavenged from a printer. He also successfully connected a larger 4 line display with back-light from a first generation hand-held GPS.

New Table Lamp

View of the base of a lamp D3 made from an interesting insulator rescued after the local electric company replaced it. Likely out in the weather for many years, the porcelain is still in fine shape.

120 Watts with Excellent Specs

Just arrived today from the UK: only $25 for a completely integrated 120 watt amplifier with very good performance characteristics. We had this up and running in short order with as much volume as we dared to push through our test speaker! Perfect for the signal chain feeding the larger speakers in our prototype design.

Synchronous Chorusing of two Peepers

Females have a perceptual bias towards the first call of a sequence. The males have evolved to
make call-timing adjustments to their own free-running call period in response to competitors in their immediate environment. This is a short segment of a recording of the advertisement calls of two males. The frogs were approximately four feet apart; the microphone was held equidistant between the two. In this trace, one frog delays his call until he becomes the leading caller. As this calling bout continued, the other frog subsequently adjusted his timing to become the first caller; this pattern repeates througout the recording. The original audio can be found by clicking on the title of this post. Our next step is a stereo recording with two microphones as the live effect is striking.