New to Basic Stamp : Occurence Counting and Displaying Voltage

Archiver

Group,

I am interested in using a Basic Stamp to
1) count occurences of Vout > Vthres
2) counting amount of time Vout > Vthres and
3) displaying output to LCD display.

For my Senior Design project I am designing a two-way mirror system
and the intensity of the lights are to be controlled by the
amplitude of Alpha brainwaves.

The EEG I have purchased integrates and averages all the brainwaves
produced in the 8 - 13 Hz range (Alpha) and outputs a variable
voltage ( +-10V)

I am interested in allowing the participant to control the threshold
voltage that is req'd for the lights to be activated. Beating the
threshold will increase the intensity of the lights.

Any guidance towards source / tutorials / insight would be
appreciated.

Brandon Taylor
Louisiana State University

Archiver

I know for a fact that this is possible because I helped a 12-year old
do it about 9 years ago for a Science Fair project using a BS1 (and he
won!). He used a comparator circuit to indicate voltage level
(under-voltage in his case [noparse][[/noparse]he was monitoring battery discharge rates]).

Since he was using a BS1 we kept the code very simple. Like this
(psuedo-code):

IF Battery_OK
Increment Seconds Timer
Update LCD
PAUSE 1 second
Check again

Actually, Dustin was comparing batteries head-to-head, so he was
checking two inputs and displaying the effective use time of different
battery brands given the same load.

You could use an ADC to measure Vout and set your threshold in software.
If you need timing resolution greater that 100 ms or so, I would suggest
using a hardware RTC.

-- Jon Williams
-- Parallax

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Original Message

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From: Brandon [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=a3Bav_iJ0O6ph90Fmtii5NW7zMlUEVZ-r-MOgctJM0tQIX3GJ_bHxivqN8fSyaSmunGlpOUDh3E]btaylo7@l...[/url
Sent: Saturday, February 28, 2004 9:33 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] New to Basic Stamp : Occurence Counting and
Displaying Voltage



Group,

I am interested in using a Basic Stamp to
1) count occurences of Vout > Vthres
2) counting amount of time Vout > Vthres and
3) displaying output to LCD display.

For my Senior Design project I am designing a two-way mirror system
and the intensity of the lights are to be controlled by the
amplitude of Alpha brainwaves.

The EEG I have purchased integrates and averages all the brainwaves
produced in the 8 - 13 Hz range (Alpha) and outputs a variable
voltage ( +-10V)

I am interested in allowing the participant to control the threshold
voltage that is req'd for the lights to be activated. Beating the
threshold will increase the intensity of the lights.

Any guidance towards source / tutorials / insight would be
appreciated.

Brandon Taylor
Louisiana State University





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