attiny core 85 for arduino - analogRead (fix)

[Paul Adams]

was struggling with the analog read last week, for those that are using
the core 85 here is what i've learnt:

you need to set your voltage reference, its not done by default to save
space..

analogReference(0);

-- pick one of these,
http://code.google.com/p/arduino-tiny/source/browse/trunk/hardware/tiny/cores/tiny/wiring.h?r=64


// X 0 0 VCC used as Voltage Reference, disconnected from PB0 (AREF).
#define DEFAULT (0)

// X 0 1 External Voltage Reference at PB0 (AREF) pin, Internal Voltage
Reference turned off.
#define EXTERNAL (1)

// 0 1 0 Internal 1.1V Voltage Reference.
#define INTERNAL (2)
#define INTERNAL1V1 INTERNAL

// 1 1 1 Internal 2.56V Voltage Reference with external bypass capacitor
at PB0 (AREF) pin(1).
#define INTERNAL2V56 (7)

Also the returned values are reversed, high is 0 and low is 1023.. so
just 1023 - value .. but then if you are reading this you already know
it since digital write is backwards, high turns the led off and low
turns it on :)





--
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Writers who use a computer swear to its liberating power in tones that
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conviction results from something deeper than mere gratitude for the
computer's conveniences.
Every new medium of writing brings about new intensities of religious
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In the 20th century this history of tragedy and triumph is repeating
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Those who worship the Apple computer and those who put their faith in
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other. Each thinks that it is itself the one hope for salvation.
-- Edward Mendelson, "The New Republic", February 22, 1988

[sun sunny]

a lot of efforts need to made to use attiny .....

2012/9/10 Paul Adams <niha...@gmail.com>

[Paul Adams]

it's pretty straight forward, just no documentation on the core45_85
which made me struggle with something so simple as voltage reference!!
will be in the space tomorrow evening finishing Mr Octapussy..

Updates:
Edward.. i took a 1.5M LDR from you
Mika.. I took an 8pin DIP socket from you

i love you both!

On Mon Sep 10 00:07:12 2012, sun sunny wrote:
> a lot of efforts need to made to use attiny .....
>

> 2012/9/10 Paul Adams <niha...@gmail.com <mailto:niha...@gmail.com>>

>
> was struggling with the analog read last week, for those that are
> using the core 85 here is what i've learnt:
>
> you need to set your voltage reference, its not done by default to
> save space..
>
> analogReference(0);
>
> -- pick one of these,

> http://code.google.com/p/__arduino-tiny/source/browse/__trunk/hardware/tiny/cores/__tiny/wiring.h?r=64

[Paul Adams]

and for you! http://hackaday.com/tag/hvsp/

On 9/10/12 12:07 AM, sun sunny wrote:
> a lot of efforts need to made to use attiny .....
>

> 2012/9/10 Paul Adams <niha...@gmail.com <mailto:niha...@gmail.com>>

>
> was struggling with the analog read last week, for those that are
> using the core 85 here is what i've learnt:
>
> you need to set your voltage reference, its not done by default to
> save space..
>
> analogReference(0);
>
> -- pick one of these,

> http://code.google.com/p/__arduino-tiny/source/browse/__trunk/hardware/tiny/cores/__tiny/wiring.h?r=64