Electronics and Software Development

Kiteboat Logger Power Control

5/2/11

We can now start and stop the kiteboat logger and verify that it is powered on without opening its protective waterproof case or connecting from a remote device. This has involved running the power switch and LED from the internal PC to a waterproof switch on the outside of the case, a job which was made trickier by the miniaturization of the PC. This operation also opens the way to making an external supervisory circuit that can control the PC power and monitor the battery state on longer excursions.

Other recent improvements to the logger include auto-detection of removable media, software to assist with calibration of the wind sensor while we are on the water, and an independent charging port. […more]

KAIView Map Update

5/2/11

KAIView 0.2.6 contains several improvements from the last few weeks, particularly in the mapping component and its integration with the other data displays. The overall goal has been to make the mapping window more useful as a primary interface to the data, instead of just a supplement to the graph display. By default the map window is now larger, the data that it already displayed is easier to read, and a legend shows the geographic scale and the meaning of the color-coded data.

In addition to these visual changes, there is now better correspondence between selections made in the graph window and those made in the map. Right-clicking and dragging in either view will create a selection that is shown […more]

Rokkaku & Android camera setup test – Mar 31

3/31/11

We took the “good” kite from the last two rokkaku tests out to the parking lot to compare its performance to that of the original carbon spar kite in very low wind.

Additionally, Jamie debuted his Android phone camera system by attaching one phone, in a padded cardboard box, to the kite line of the carbon-sparred kite and letting it out about 75m. In his hand he held another Android phone, which displayed the image taken by the lofted camera.

Meanwhile, Don and Dudu discussed weight differences in the two kites and experimented with bridle positions on the inflatable one. We also briefly attached a GoPro to the line of the inflatable kite to get an aerial view of the […more]

New Logger Thermal Test

3/2/11

Jamie put the logger components in a new box (orange, on top) that is even smaller than the old box (silver, on bottom). Right now he is running a program on the Android phone to record the temperature to make sure that the electronics will not overheat in their new closer quarters.

The graph shows the temperature recorded by a Nexus S phone, using software that we wrote to log its battery temperature. (The PC either has no non-CPU temperature sensors or they are not visible to the OS.) The phone battery temperature is typically a few degrees higher than the ambient temperature. While the temperature did not fully stabilize during the 2.5 hour test, it appeared to be leveling […more]

Android + Bluetooth Servo Controller

2/11/11

We are exploring the use of our new Nexus S Android phone as a kite-based programmable wireless camera and pan/tilt controller. The first step in making this happen was to make a bluetooth connection to an RC servo controller and control it from the phone.
For extra fun, we mapped the phone’s orientation to its commands so that the pan/tilt unit tracks the phone’s rotations.

Next we will improve the app so that a user interface on a second phone or a remote computer can control the phone remotely over a socket connection. The final step will be to transmit both low-resolution, low-latency “preview” images and full-resolution images from the phone back to its client.

Cameras on the boat + movie

5/25/10

For each boat test, we mount several cameras on the kite, kite lines, and boat in order to have a visual record of performance. Don is always experimenting with new camera technology, but currently we are using almost entirely GoPro HD HEROs for the video footage. For stills, we use the older GoPro HEROs and Pentax Optio W60s. The HD GoPros are capable of taking very high quality footage and have a nifty wide-angle lens. Unfortunately, that lens means that they aren’t the best kitecams. The W60s are still a good option for the kite, but their video quality is noticeably lower.

As you can see in photos, the GoPros are not waterproof; they are housed in little waterproof cases […more]