Why is Attiny85 so popular?

Discussions on the software and hardware for Atmel's STK standard.

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Why is Attiny85 so popular?

Post by thankyou » Sun May 17, 2015 11:09 pm

I'm confused about why the Attiny85 is more popular (on hobby electronics sites) than the picoPower microcontrollers like Attiny43U. Why doesn't everyone want the lowest current consumption, as well as an Attiny with a built in booster to 3V? I'm not sure if there's something I'm missing. I have been using the Attiny85 in my project, and I found out that it was responsible for the majority of the 20 mA current draw. Now I regret not using Attiny43U because I could have had much better battery life.

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Re: Why is Attiny85 so popular?

Post by leon_heller » Mon May 18, 2015 2:09 am

The ATtiny85 is available in DIL.
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Re: Why is Attiny85 so popular?

Post by thankyou » Mon May 18, 2015 9:44 am

That's all? It seems easy enough to use a breakout board for a surface mount microcontroller...

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Re: Why is Attiny85 so popular?

Post by leon_heller » Mon May 18, 2015 10:16 am

Why don't you use it?
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Re: Why is Attiny85 so popular?

Post by Ross Robotics » Mon May 18, 2015 10:26 am

The reason is most people buy what is offered. The majority won't search Atmel's site to see what controller would best suit their needs. They just buy what sites have..
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Re: Why is Attiny85 so popular?

Post by thankyou » Mon May 18, 2015 11:10 am

Interesting...I was the same way and I saw it as convenient that there was a Tiny AVR programmer for the Attiny85 that I could use with Arduino. Now I'm going to figure out how to program the Attiny43U...

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Re: Why is Attiny85 so popular?

Post by jremington » Mon May 18, 2015 11:58 am

You can dramatically reduce the power consumption of the ATtiny85 by employing proper power reduction techniques and having the processor sleep whenever possible. Much of the material in the following link to power reduction for the ATmega series also applies to the ATtiny series. http://www.gammon.com.au/power

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Re: Why is Attiny85 so popular?

Post by thankyou » Mon May 18, 2015 4:12 pm

Thanks for the link...Unfortunately I don't think there's much I can do because my program cannot go into sleep mode as I'm constantly reading from the ADC.

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Re: Why is Attiny85 so popular?

Post by skimask » Mon May 18, 2015 7:20 pm

Is it REALLY necessary to read from the ADC constantly? 100:1 says probably not...which also happens to be just about the ratio of current you could save by putting the thing to sleep in between the really necessary readings.
...but then again, as usual, we know nothing about the situation at hand...
I ignore "one post wonders".

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Re: Why is Attiny85 so popular?

Post by thankyou » Tue May 19, 2015 12:13 am

I'm monitoring something with the ADC that can change at any moment, so I do have to read from the ADC constantly...I better read up on programming Attiny43U :)

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Re: Why is Attiny85 so popular?

Post by skimask » Tue May 19, 2015 5:04 am

....something....
I ignore "one post wonders".

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Re: Why is Attiny85 so popular?

Post by jremington » Tue May 19, 2015 8:06 am

I'm monitoring something with the ADC that can change at any moment, so I do have to read from the ADC constantly
If it is so important to know exactly when the ADC input changes, what happens when the batteries fail? Seems like a poor overall approach.

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Re: Why is Attiny85 so popular?

Post by uChip » Tue May 19, 2015 8:23 am

I agree with jremington. Remember that human time and MCU time are different. An MCU can be asleep 90% of the time and still respond in less than a second. Or if timing is that critical then use a micropower circuit to detect the event and wake the MCU when it happens.

In case you didn't get the other hint: If you would tell us more about what you are trying to do, we could be more helpful with our suggestions.

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Re: Why is Attiny85 so popular?

Post by thankyou » Tue May 19, 2015 11:53 am

I'm using the ADC to read an analog distance sensor value, and I want an action to occur at the precise moment the analog reading is above a value (this value can be modified by the user, so I wouldn't want to use a comparator).

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Re: Why is Attiny85 so popular?

Post by jremington » Tue May 19, 2015 12:32 pm

It is impossible to know the "precise moment" that something occurs. An ADC reading can take a couple of hundred microseconds.

A comparator can compare an input to another voltage, set by a standard or digital potentiometer, and is thus adjustable by the end user. Furthermore, the comparator has higher resolution than the ADC and can wake the part up from sleep. So the ADC is neither necessary nor desired.

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