3V test
Archiver
Posts: 46,084
Often someone's posting brings up a related, but different thought......
I want to test a 3V output device with a Stamp 2 or 2p's shiftout
instruction, before advancing the project to a PIC or AVR.
Before re-inventing the wheel, I thought I might poll the group to see if
anyone has a canned method for doing such a thing?
(because, after all...there is nothing new under the sun...)
Chris
I want to test a 3V output device with a Stamp 2 or 2p's shiftout
instruction, before advancing the project to a PIC or AVR.
Before re-inventing the wheel, I thought I might poll the group to see if
anyone has a canned method for doing such a thing?
(because, after all...there is nothing new under the sun...)
Chris
Comments
precision.
A cheap way would be to use a voltage comparator LM339 (Radio Shack has em
too), set it's reference to 3v and you get a high or low on the output. With
four comparators to a chip you could set all four at slightly different
levels around 3v and have four differnt outputs.
Some of the AVR chips have a 8 channel comparator built in, so you could use
them directly, in that manner.
Using a comparator, sort of eliminates using the shift in or out method,
unless you throw in a 1wire digital potentiometer to adjust the reference
voltage on the comparators.
Original Message
From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=eNDjkBWcj6G8bzUv-vk8HovXQ_UHpJwAuD99uRNSBIrvsEqRa_kHuTsAc2i-wpRIPkk2NO4zPoUokQ]chris@m...[/urlOn Behalf Of Chris
Loiacono (E-mail)
Sent: Monday, January 14, 2002 10:46 AM
To: Basicstamps Group (E-mail)
Subject: [noparse][[/noparse]basicstamps] 3V test
Often someone's posting brings up a related, but different thought......
I want to test a 3V output device with a Stamp 2 or 2p's shiftout
instruction, before advancing the project to a PIC or AVR.
Before re-inventing the wheel, I thought I might poll the group to see if
anyone has a canned method for doing such a thing?
(because, after all...there is nothing new under the sun...)
Chris
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/
My 3V output device is a graphical LCD driver/controller. I want to send
serial data to it with a Stamp - as a test, or trial before writing a PIC18
program that will also run on a 3V supply.
Sorry if I wasn't too clear...
Chris
>
> If your fancy, you would use a ADC and measure the voltage.
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=q_8BcnDSnJQiBikk_djDEXyDMGujL4lfPSWAaivmNSshTmS3-gvvhgTFimg2qei-jRsB-pe2I8QhJK4]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, January 14, 2002 10:46 AM
> To: Basicstamps Group (E-mail)
> Subject: [noparse][[/noparse]basicstamps] 3V test
>
>
> Often someone's posting brings up a related, but different
> thought......
> I want to test a 3V output device with a Stamp 2 or 2p's shiftout
> instruction, before advancing the project to a PIC or AVR.
> Before re-inventing the wheel, I thought I might poll the
> group to see if
> anyone has a canned method for doing such a thing?
> 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/
>
>
How about a simple resistor divider for stamp outputs like
Stamp pin
[noparse][[/noparse]4k7]--+
3V device input
output | max. 2.72V (assuming threshold 70% of 3V =
2.1V)
[noparse][[/noparse]5k6]
|
|
V
The only problem here may be bidirectional lines, but if you use the above
circuit also
for stamp inputs, it may even work as the 4k7 resistor should have no effect
and 3V is well above the stamp input treshold.
Regards peter
Oorspronkelijk bericht
Van: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=-g6fMcEcHKSboHNro2riq6WTHixhuJfWUwj0CRRbWwGtn_-DRo7g99Y6hAscM08m-CvinzYLZKh7]chris@m...[/urlNamens Chris Loiacono
(E-mail)
Verzonden: dinsdag 15 januari 2002 14:05
Aan: basicstamps@yahoogroups.com
Onderwerp: RE: [noparse][[/noparse]basicstamps] 3V test
Thanks Earl, but....
My 3V output device is a graphical LCD driver/controller. I want to send
serial data to it with a Stamp - as a test, or trial before writing a PIC18
program that will also run on a 3V supply.
Sorry if I wasn't too clear...
Chris
>
> If your fancy, you would use a ADC and measure the voltage.
>
Original Message
> From: Chris Loiacono [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=-g6fMcEcHKSboHNro2riq6WTHixhuJfWUwj0CRRbWwGtn_-DRo7g99Y6hAscM08m-CvinzYLZKh7]chris@m...[/urlOn Behalf Of Chris
> Loiacono (E-mail)
> Sent: Monday, January 14, 2002 10:46 AM
> To: Basicstamps Group (E-mail)
> Subject: [noparse][[/noparse]basicstamps] 3V test
>
>
> Often someone's posting brings up a related, but different
> thought......
> I want to test a 3V output device with a Stamp 2 or 2p's shiftout
> instruction, before advancing the project to a PIC or AVR.
> Before re-inventing the wheel, I thought I might poll the
> group to see if
> anyone has a canned method for doing such a thing?
> 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/
>
>
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/