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September 14, 2011
News - Your March Caption Contes… |
about a month ago
Seriously… who slept in my dog’s bed?
Product SEN-11744 |
I agree and apologize for any possible disinformation. You can however hook these up directly to any ADC with differential inputs.
I may have been a little too quick to type that.
Since the arduino doesn’t have differential inputs, you’d have to inject a voltage ½ of your ADC reference voltage.
I’d like to see a schematic too. I do have a few of my own personal schematics to interface these types of sensors to ADCs. Can I give my email address on here?
Sure, you can hook it up directly if you want. It will work.
What you suggest about precision op amps and an LPF is exactly how high-end seismic equipment is created.
It is a good quality magnet suspended by springs, surrounded by a coil. So, very similar to a microphone. Also these are similar to an accelerometer as well, just made for lower frequencies. I work with these all the time at my job.
All you need to know is a few things to get started:
Orientation… there are vertical and horizontal orientated versions which allow you to create a true tri-axial configuration using 3 geophones (1 vertical, 2 horizontal).
Sensitivity. Volt/inch per sec.
Frequency response. Most geophones are very linear from about 2-500hz. There will be a higher sensitivity in the geo’s sweet spot or natural frequency. You can also use a dampening resistor to make it much more linear in response but at the cost of sensitivity.
Product COM-09935 |
about 2 years ago
I’ve used the LM3916 with these in the past. It’s very similar to the LM3914/15. They all drive 10 LEDs which is a perfect fit. Plus, no need for a uC interface, they can be completely stand-alone.
Hook up the RSSI PWM output from an xbee module through a low-pass filter, into one of these LM3916 and you have something pretty cool…
Product GPS-10890 |
about 2 years ago
Looks as if it would be possible to solder your own wires to the 6 pads next to the connector…
Product BOB-10160 |
about 3 years ago
I had the same problem and did what you said, used 0021 and it works fine now.
Although, the original sketch worked for me. I had problems when changing the numbers sent with the SetTimeDate function. Sometimes it would output the ReadTimeDate correctly until it got to a certain time and would lock up.
No public wish lists :(