RE: TI-H: pressure sensor

To: ti-hardware@lists.ticalc.org
Subject: RE: TI-H: pressure sensor
From: gussie@alaska.net (Grant Stockly)
Date: Sat, 31 Jan 1998 20:31:38 -0700
Reply-To: ti-hardware@lists.ticalc.org

We know the drill and how to interface things with our calculators.

>        I just signed up to this list, but I'd just like to warn you all
>that I think the TI's input protocol is a lot more complicated than
>that. Yes, you convert the voltage into a digital signal, but you also
>have to frame that data with a whole bunch of control characters to tell
>the TI that you have real data, and not just random noise. A project
>similar to this-- ie, designing a voltage meter on a TI-- is my senior
>year research. I'll be glad to help you out in any way, but it is quite
>a bit harder than you might think.... Sorry for the news...
>
>matt zimmerman
>biochemist extraordinare
>
>> ----------
>> From:         ryan pogge[SMTP:ryanpogge@hotmail.com]
>> Reply To:     ti-hardware@lists.ticalc.org
>> Sent:         Saturday, January 31, 1998 9:12 PM
>> To:   ti-hardware@lists.ticalc.org
>> Subject:      Re: TI-H: pressure sensor
>>
>>
>> sounds cool to me anyone want to help me out, i can build it but i
>> cant
>> write a driver.
>> and i would realy like to build it :)
>>
>>
>> >Use an I2C A/D converter!
>> >
>> >
>> >>    ____
>> >>   /    \          pin 1 is VCC 5 volts
>> >>  |  o   |         pin 2 is ground
>> >>   \____/          pin 3 is Vout (betwean 0-5 volts)
>> >>   /||||\          pins 4-6 are not used
>> >>  | |||| |
>> >>  1 2345 6  _____
>> >   | ||_____| I2C |____________SCL
>> >   |_|______| A/D |____/\/\
>> >   | |______|     |________|___SD   I'm not sure about the
>> >   | |      |_____|                 Interface side of the I2C chip
>> >   + -
>> >
>> >I'm not exactly sure if this is right, but I'm sure it will work in
>> it's
>> >most basic form. There may be things like a reference voltage or
>> >something like that. If anyone knows anything about an I2C A/D
>> >converter, fix this schematic.
>> >
>> >Richard Piotter
>> >richfiles1@hotmail.com
>> >
>> >>
>> >>I was wondering if we could make a pressure sensor for the 85(or any
>>
>> >>other calc for that matter.
>> >>
>> >>I have a motorola mpx4100a presure sensor.
>> >>it looks like this.
>> >>
>> >>    ____
>> >>   /    \          pin 1 is VCC 5 volts
>> >>  |  o   |         pin 2 is ground
>> >>   \____/          pin 3 is Vout (betwean 0-5 volts)
>> >>   /||||\          pins 4-6 are not used
>> >>  | |||| |
>> >>  1 2345 6
>> >>
>> >>is it possible to have a assembly program sense the voltage  comeing
>>
>> >>into the link port? i dont know assembly so i would need some one to
>>
>> >>write the driver..but the pressure is related to Vout by an equation
>>
>> >>which you can find at along with the data sheet here:
>> >>http://mot2.indirect.com/cgi-bin/get?/books/dl200/pdf/mpx4100rev*.pd
>> f
>> >>
>> >>if anyone thinks this is a possible project or would like to help.
>> >>please let me know.
>> >>the hardware is easy i just need someone to help with drivers.
>> >>
>> >>
>> >>
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>> >>
>> >
>> >
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>>
>>
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---
Grant Stockly
AppleCyber - http://www.alaska.net/~gussie