loggers

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]

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]