Steve Hammond wrote: > > Has anybody incorporated a BasicStamp micro in the > construction of their seismograph, tools, amplifiers, > or A/D? > Regards, Steve Hammond -- PSN Aptos, California About 10 years ago I got tired of re-leveling a garden-gate type seismograph (a one vertical post "Lehman") that was more stable than its base. (A machine adjusted to 20 second period on a house slab needs daily re-leveling in changeable weather.) I used the BasicStamp to: a) send a re-leveling indication to the ADC b) short the sense coil c) turn on 2 infra-red LEDs used to help sense the pendulum position d) sense the relative outputs of two infra-red photo cells using an RC circuit BasicStamp AtoD recommended at the time e) operate a highly geared down stepping motor to move the leveling more toward nominal pendulum position f) undo c) above, then b), then a) g) go back to sleep for a day Results of the experiment. a) BasicStamp ALMOST had the drive to operate the stepping motor reliably - had to go to higher current drive to gain 100% drive reliability b) photo sensing using the old recommended BasicStamp circuit is a bitch !! - temperature sensitivity - sensitivity to ambient light - sensitivity to everything even using differential circuitry did not yield the kind of reliability and stability and demonstratability that I wanted. Then I discovered the Internet, and my interests changed. If I were going to do it again - a) more conventional AtoD than offered by the old BasicStamp - like a real amplifier and a real ADC (or a more modern BasicStamp?) b) pay more attention to the optics so that I can show the thing working to my friends in normal light. or c) tap into the data from a professionally operated machine installed in a quiet location (2000 miles from a sea coast OR install a 0.2 to 0.1 Hertz notch filter). Cheers Ed Thelen - Fremont, CA ethelen@........ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>