Earl, you may want to try the BaroMod, same cost, but provides a linearized output, 0.25mV per foot, so you
don't have to do nasty math to get a real alt. In hardware, an anti-log amp, the correct voltage is output to your
a/d input. The atmosphere has a log pressure function, a bit hard to straighten out with bit banging in PICs , for sure.
* The BaroMod allows easy altitude measurement using any 0-5V analog electronics or embedded processor, with at least a 10 bit a/d converter.
* An anti-log amp is used to create a linear response. No complex software math is required to process sensor signal, freeing up computer for logging or telemetry tasks.
* Typical usage with 10 bit a/d will yield 20' measurement steps, good for general purpose application. Higher res is ok.
Size: 2.05" x 1.15" x 0.65"
Weight: 17 grams
DC Supply: 5V
Range: -500' below sea level to 20,000'
Output: 0-5V linear, proportional response, 0.25mV/ft.
Modes: absolute,differential (subtract ground reading)
Temperature Range: -40 to 200 deg. F
Typ. usage: Feeding to 10 bit a/d results in 20' increments
Replies
don't have to do nasty math to get a real alt. In hardware, an anti-log amp, the correct voltage is output to your
a/d input. The atmosphere has a log pressure function, a bit hard to straighten out with bit banging in PICs , for sure.
I have resolved a couple feet with this unit.
Under products at:
http://www.transolve.com/Transolve/index.html
* The BaroMod allows easy altitude measurement using any 0-5V analog electronics or embedded processor, with at least a 10 bit a/d converter.
* An anti-log amp is used to create a linear response. No complex software math is required to process sensor signal, freeing up computer for logging or telemetry tasks.
* Typical usage with 10 bit a/d will yield 20' measurement steps, good for general purpose application. Higher res is ok.
Size: 2.05" x 1.15" x 0.65"
Weight: 17 grams
DC Supply: 5V
Range: -500' below sea level to 20,000'
Output: 0-5V linear, proportional response, 0.25mV/ft.
Modes: absolute,differential (subtract ground reading)
Temperature Range: -40 to 200 deg. F
Typ. usage: Feeding to 10 bit a/d results in 20' increments
Price - US$38 + $5 ship