Amazing Mega 0-series

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Just checked on DigiKey.

 

An ATmega808 in a 28-pin SSOP package can be gotten for for $0.89 USD in single quantity. In larger quantity, its $0.75 each.

 

This device has 8K of flash and 1K of ram! And, it has all the great 0-series peripherals shared by the larger members of that group.

 

What a buy!

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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True, they have good value, but always keep in mind the caveat that this series doesn't have the quartz crystal driving circuitry.

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The problem is just that you can get a ARM with 32K Flash and 4KRAM for the same price.

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sparrow2 wrote:

The problem is just that you can get a ARM with 32K Flash and 4KRAM for the same price.

 

Well, actually you can get a Cortex-M3 64K/8K for 50 cents: https://lcsc.com/product-detail/...

The advantage of 8 bit chips IMO is just that they are simpler to configure and support 5V (if you need that) which ARM usually don't at this price range.

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My little "essay" about complexity in the programming forum addresses the issue of ARM vs AVR 0-series, sort of. Sometimes, cost is not the only factor.

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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ka7ehk wrote:

My little "essay" about complexity in the programming forum addresses the issue of ARM vs AVR 0-series, sort of. Sometimes, cost is not the only factor.

 

Jim

Link?

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Sorry, that is indeed the cross-link.

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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sparrow2 wrote:

The problem is just that you can get a ARM with 32K Flash and 4KRAM for the same price.

My question now is: Why it is no possible to get simple 8Bit controller with higher frequencies, much more flash and sram?
Why do I have to accept a higher (32Bit ARM) complexity today in order to get much more from it? Many applications do not require the elaborate flexibility and rich functionality = complex & confusing configuration of these types. Only more performance and memory space.

Last Edited: Wed. Nov 20, 2019 - 10:35 PM
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GermanFranz wrote:
Why it is no possible to get simple 8Bit controller with higher frequencies, much more flash and sram?
CMOS power dissipation is proportional to the frequency and the square of the voltage (affects MOSFET size)

An 8-bit advantage is wide voltage.

GermanFranz wrote:
Only more performance and memory space.
AVR DA-series

What are the AVR28DA128 AVR32DA128 AVR48DA128 AVR64DA128 ?? | AVR Freaks

 

"Dare to be naïve." - Buckminster Fuller

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GermanFranz wrote:
My question now is: Why it is no possible to get simple 8Bit controller with higher frequencies, much more flash and sram?
Why do I have to accept a higher (32Bit ARM) complexity today in order to get much more from it? Many applications do not require the elaborate flexibility and rich functionality = complex & confusing configuration of these types. Only more performance and memory space.
There's a number of new AVRs that now have 16KB of SRAM (previously it was just 12384P). However they are a "new" architecture compared to traditional tiny/mega so you are going to be learning a whole new raft of peripherals anyway and the argument may well go that if you are going to do that anyway you might as well be learning Cortex-M.

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They don't want to make a simple 200MHz AVR...it might scare the ARM chips away (too many developers might go for simplicity).

The Man is holding the designers who want faster AVR's back.

 

Maybe the AVR's can actually run at 100MHz at 5V , but they don't want us to know it...I wonder how fast they've been successfully "overclocked"?

 

Maybe there is a speed cartel, along the lines of the famous light bulb conspiracy, first organized by Osram head William Meinhardt

https://spectrum.ieee.org/tech-history/dawn-of-electronics/the-great-lightbulb-conspiracy

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Thu. Nov 21, 2019 - 10:09 AM
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clawson wrote:

the argument may well go that if you are going to do that anyway you might as well be learning Cortex-M.

 

32 bit MCUs always seem to have much more complex peripherals. It's as if hardware designers, realizing they have 32 bit SFRs instead of 8/16 bit ones, feel some kind of compulsion to keep adding features until most of those 32 bits have some role in the peripheral frown

Last Edited: Thu. Nov 21, 2019 - 10:52 AM
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GermanFranz wrote:
Why it is no possible to get simple 8Bit controller with ... much more flash and sram?

One reason is that you can't address much memory with only 8 bits!

 

So you have to start adding special, extra-wide registers to give you a decent address size.

And you need extra logic to handle those "wide" values.

And the instructions have to get bigger to fit the addresses in.

 

So you end up saying, "why not just make it a 32-bit processor?"

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El Tangas wrote:
32 bit MCUs always seem to have much more complex peripherals

This is true.

 

Most of the "ARM is so complex" whingeing is really not about ARM at all - it's about the peripherals that the chipmakers have chosen to bolt onto the ARM.

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awneil wrote:

One reason is that you can't address much memory with only 8 bits!

 

Many 8 bit mcus can address much more than 256 flash bytes.

That can not be the reason wink

 

awneil wrote:
So you end up saying, "why not just make it a 32-bit processor?"

 

I can not and do not want to understand exactly this conclusion (that means of course including all the consequences of designing today's 32 bit controllers).

 

avrcandies wrote:
They don't want to make a simple 200MHz AVR...it might scare the ARM chips away (too many developers might go for simplicity).
.

 

That seems to me the real motivation.

And simplicity as an attractive feature is still underestimated.

I can only guess frown

I only know what I want and need...

But I'm pretty sure I'm not the only one with this crazy wishes wink

 

Last Edited: Thu. Nov 21, 2019 - 11:40 AM
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GermanFranz wrote:
Many 8 bit mcus can address much more than 256 flash bytes.

Of course they do - and that's what the rest of the post was about!

I further wrote:
So you have to start adding special, extra-wide registers to give you a decent address size ... etc ...

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  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
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Last Edited: Thu. Nov 21, 2019 - 12:07 PM
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Another thing with ARM (or any 32 bit) versus AVR (or any 8 bit) is that memory is generally accessed in 32 bit (4 byte) so RAM tends to be 4 times the size. A 16K flash 8bit might typically have 1K RAM but a 16K flash 32 bit will likely have 4K RAM. So you always tend to find the flash/RAM ratio is larger (x4) with the larger bit width.