Digest Number 1027
For interfacing with my BasicStamp2
I am in search of a digitally controlled potentiometer with a range of 1
kOhm to 10 mega Ohm most on the web i find have too narrow range (16 steps
in enough for what i need). I think nobody manufacture chip with this wide
range...
So i also search a chip that act as a 5 position digital rotary switch.
My project involve reading a photoresistor interfaced with an
AnalogDigitalConverter, but i want to have
5 different resistors (1k, 10k, 100k, 1M, 10M) in order to autoselect the
best range reading to have the best linearity in my reading.
I want to have the selected fixed resistor << photresistor this give me the
best precision and the best sensivity and the best linearity in ADC reading.
(Voltage divisor)
+5v
/\/\/\/\/\/\/\/\/\/\/\/\/\/\
o
(A)
(B)
/\/\/\ 1k /\/\/\/\/\
Ground
PhotoResistor !
(C)
/\/\/\ 10k /\/\/\/\
Ground
!
(D)
/\/\/\ 100k /\/\/\
Ground
!
(E)
/\/\/\ 1M /\/\/\/\/\
Ground
Input to ADC
(F)
/\/\/\ 10M /\/\/\/\
Ground
!
!
!
To basic stamp
I wish the basic stamp to connect (A) with (B) or (C) or (D) or (E) or (F)
After each connection i read the ADC result, at the end, i have 5 values, i
just choose the best value for me. By the way i have just 5 pins left on my
basicstamp2
I try some klever connection (that's what i think on paper) with diode but
worth nothing.
I am in search of a digitally controlled potentiometer with a range of 1
kOhm to 10 mega Ohm most on the web i find have too narrow range (16 steps
in enough for what i need). I think nobody manufacture chip with this wide
range...
So i also search a chip that act as a 5 position digital rotary switch.
My project involve reading a photoresistor interfaced with an
AnalogDigitalConverter, but i want to have
5 different resistors (1k, 10k, 100k, 1M, 10M) in order to autoselect the
best range reading to have the best linearity in my reading.
I want to have the selected fixed resistor << photresistor this give me the
best precision and the best sensivity and the best linearity in ADC reading.
(Voltage divisor)
+5v
/\/\/\/\/\/\/\/\/\/\/\/\/\/\
o
(A)
(B)
/\/\/\ 1k /\/\/\/\/\
Ground
PhotoResistor !
(C)
/\/\/\ 10k /\/\/\/\
Ground
!
(D)
/\/\/\ 100k /\/\/\
Ground
!
(E)
/\/\/\ 1M /\/\/\/\/\
Ground
Input to ADC
(F)
/\/\/\ 10M /\/\/\/\
Ground
!
!
!
To basic stamp
I wish the basic stamp to connect (A) with (B) or (C) or (D) or (E) or (F)
After each connection i read the ADC result, at the end, i have 5 values, i
just choose the best value for me. By the way i have just 5 pins left on my
basicstamp2
I try some klever connection (that's what i think on paper) with diode but
worth nothing.
Comments
be digitally controlled. apair of them would allow you to select up to 8
separate resistors.
Original Message
From: "Bruno.Dionne" <brudio@g...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, January 08, 2002 7:22 PM
Subject: Re: [noparse][[/noparse]basicstamps] Digest Number 1027
> For interfacing with my BasicStamp2
>
> I am in search of a digitally controlled potentiometer with a range of 1
> kOhm to 10 mega Ohm most on the web i find have too narrow range (16 steps
> in enough for what i need). I think nobody manufacture chip with this wide
> range...
>
> So i also search a chip that act as a 5 position digital rotary switch.
>
>
> My project involve reading a photoresistor interfaced with an
> AnalogDigitalConverter, but i want to have
> 5 different resistors (1k, 10k, 100k, 1M, 10M) in order to autoselect the
> best range reading to have the best linearity in my reading.
>
> I want to have the selected fixed resistor << photresistor this give me
the
> best precision and the best sensivity and the best linearity in ADC
reading.
>
>
> (Voltage divisor)
>
> +5v
/\/\/\/\/\/\/\/\/\/\/\/\/\/\
o
(A)
> (B)
/\/\/\ 1k /\/\/\/\/\
Ground
> PhotoResistor !
> (C)
/\/\/\ 10k /\/\/\/\
Ground
> !
> (D)
/\/\/\ 100k /\/\/\
Ground
> !
> (E)
/\/\/\ 1M /\/\/\/\/\
Ground
> Input to ADC
> (F)
/\/\/\ 10M /\/\/\/\
Ground
> !
> !
> !
> To basic stamp
>
>
>
> I wish the basic stamp to connect (A) with (B) or (C) or (D) or (E) or (F)
> After each connection i read the ADC result, at the end, i have 5 values,
i
> just choose the best value for me. By the way i have just 5 pins left on
my
> basicstamp2
>
> I try some klever connection (that's what i think on paper) with diode but
> worth nothing.
>
>
>
>
>
>
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