Measuring Voltage
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Posts: 46,084
Hello,
Im looking for a way to measure voltage with the stamp. The sensor I
need to read has a 5 volt DC input, and it varies the output as the
pressure changes. I need to accurately measure this voltage in a very
timely manner within my circuit.
Does anyone know how this might be done?
Thank you,
Bill
Im looking for a way to measure voltage with the stamp. The sensor I
need to read has a 5 volt DC input, and it varies the output as the
pressure changes. I need to accurately measure this voltage in a very
timely manner within my circuit.
Does anyone know how this might be done?
Thank you,
Bill
Comments
define "accurate" so I'll suggest a couple: the ADC0831, 8-bit ADC
(resolution is 19.6 mV) or the LTC1298, a 12-bit ADC (resolution of 1.2 mV).
Of course, there are many others. These two get used frequently in BASIC
Stamp projects and there is plenty of example code available.
-- Jon Williams
-- Parallax
In a message dated 2/16/2003 9:38:48 AM Central Standard Time,
billak@f... writes:
> Hello,
>
> Im looking for a way to measure voltage with the stamp. The sensor I
> need to read has a 5 volt DC input, and it varies the output as the
> pressure changes. I need to accurately measure this voltage in a very
> timely manner within my circuit.
>
> Does anyone know how this might be done?
>
> Thank you,
>
> Bill
>
[noparse][[/noparse]Non-text portions of this message have been removed]
billak@f... writes:
> Hello,
>
> Im looking for a way to measure voltage with the stamp. The sensor I
> need to read has a 5 volt DC input, and it varies the output as the
> pressure changes. I need to accurately measure this voltage in a very
> timely manner within my circuit.
>
> Does anyone know how this might be done?
>
> Thank you,
>
Bill,
What kind of pressure sensor did you end up getting?
[noparse][[/noparse]Non-text portions of this message have been removed]
have over that 5 volts and what accuracy you want from it.
Lets say you're measuring 0 to 120 PSIG (0=0mV 120=5000mV). And 8 bit ADC
will give you 256 steps across 5 volts or 5000/256= 19.53125mV per step
which corresponds to 120/256=0.46875 PSI/step
If you go with a 12 bit ADC then its 4096 steps
5000/4096=1.220703125 mV/step
120/4096=0.029296875 psi/step
Some 12bit ADCs will also let you choose 10 bit mode if you don't need 12
bits but find 8 bit too coarse.
My 'lectronic Newb site http://members.shaw.ca/pmeloy/
Original Message
From: <billak@f...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, February 16, 2003 7:37 AM
Subject: [noparse][[/noparse]basicstamps] Measuring Voltage
> Hello,
>
> Im looking for a way to measure voltage with the stamp. The sensor I
> need to read has a 5 volt DC input, and it varies the output as the
> pressure changes. I need to accurately measure this voltage in a very
> timely manner within my circuit.
>
> Does anyone know how this might be done?
>
> Thank you,
>
> Bill
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Jon has mentioned a couple.
But before selecting one, you need to know a few things. What is the OUTPUT
from the pressure sensor over the range of pressure you are interested in?
(This will determine whether you need to amplify the output using an op
amp, and by how much) What is the smallest DIFFERENCE in pressures that
you need to be able to resolve? (This will determine the resolution - the
number of bits - needed in an A/D converter). What ACCURACY do you need?
How often do you need to take the readings?
Analog Devices has some sigma-delta converts with built-in amplifiers -
some are designed for pressure sensors specifically. They are relatively
cheap, and could make your life a lot easier.
Larry
At 03:37 PM 2/16/2003 +0000, you wrote:
>Hello,
>
>Im looking for a way to measure voltage with the stamp. The sensor I
>need to read has a 5 volt DC input, and it varies the output as the
>pressure changes. I need to accurately measure this voltage in a very
>timely manner within my circuit.
>
>Does anyone know how this might be done?
>
>Thank you,
>
>Bill
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Larry Bradley
Orleans (Ottawa), Ontario, CANADA
just using a Chevy MAP Sensor from an 88 Celebrity for my EFI
Project.
Bill
--- In basicstamps@yahoogroups.com, smartdim@a... wrote:
> In a message dated 2/16/2003 7:38:47 AM Pacific Standard Time,
> billak@f... writes:
>
> > Hello,
> >
> > Im looking for a way to measure voltage with the stamp. The
sensor I
> > need to read has a 5 volt DC input, and it varies the output as
the
> > pressure changes. I need to accurately measure this voltage in a
very
> > timely manner within my circuit.
> >
> > Does anyone know how this might be done?
> >
> > Thank you,
> >
>
> Bill,
> What kind of pressure sensor did you end up getting?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]