chip select for 2xUART

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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 10:54 AM
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 A while back was looking for a 8bit Avr having 2xUART, and got some tips; among which a link to a very good chip selection web-page:

chip sel link at microchip

 

I was recommended to buy a 324pb (I think), but I ended up ordering a 328p (somehow I got that that also should have 2xUART),

when I got it I (think) I realized that it wasnt capable of 2xUART after all.

 

Now Im at it again; consulting the above said link; I find to my surprise that it seems that there are NOT 28 DIP chips to dip anymore ?? 28pin not in table.

(that after making a first conclusion that, well; there seem to be no 2xUART in 28 PIN format)

 

while in:

a 28 DIP is seen in chip portraits

 

 

(implicit is that I want pins )

 

should i revert to my 2xMCU setup (SPI com inbetween) to (try) get a 2xUART ? 

suggestions ..

Tags:

AVR Microcontrollers, megaAVR and tinyAVR
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Gold Markclawson
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Posted by clawson: Tue. Oct 22, 2019 - 11:08 AM
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Note that Microchip have TWO parametric searches that include AVR. You can see links to both here:

 

https://www.microchip.com/selection-tools

 

In one of those there are just "selected" AVR and that may also mean a "selected" collection of package types. 

 

The other one is complete, so maybe try this:

 

https://www.microchip.com/maps/Microcontroller.aspx

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Bronze Marktheusch
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Posted by theusch: Tue. Oct 22, 2019 - 11:40 AM
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gechxx wrote:

should i revert to my 2xMCU setup (SPI com inbetween) to (try) get a 2xUART ? 

suggestions ..

Wouldn't that be much more expensive and power-using and board space and complicated, versus just getting a chip with two USARTS?

 

I've lost track, but aren't there pre-made AVR boards for a few bucks with twin USARTS?

 

'328PB has two USARTS.  Is that what was recommended?  But, as you learned, many new models are not made in DIP.

 

 

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 01:05 PM
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Thanks ! That select shows me 384c3 which is a nit overkill in most respects.

Well as to price I think 2xM8 bets many other opts and power is no problem, well electricity bill is actually a nuisace here but most of it fixed subscription, ( and I dont fly (not even to Thailand :) )). So I guess a struggle along fir a while. Its never too late to give up, as a collegue once put it.

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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 01:30 PM
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That said goes with that this is a prototyp and in case it gets so good that considering making a series, I will have to rethink.

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avrcandies
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Posted by avrcandies: Tue. Oct 22, 2019 - 03:08 PM
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Digikey is a pretty good place to search as well.

 

why not use a DIP adapter...many choices!

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

Last Edited: Tue. Oct 22, 2019 - 03:12 PM
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Gold Markclawson
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Posted by clawson: Tue. Oct 22, 2019 - 03:31 PM
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gechxx wrote:
I was recommended to buy a 324pb (I think)
Presumably because 324P (not 324PB) is the most obvious choice in DIP?

 

https://www.digikey.com/products/en/integrated-circuits-ics/embedded-microcontrollers/685?k=atmega324p&k=&pkeyword=atmega324p&sv=0&pv16=6538&sf=0&FV=-8%7C685&quantity=&ColumnSort=0&page=1&pageSize=25

 

I'd just go ahead and get:

 

https://www.digikey.com/product-detail/en/microchip-technology/ATMEGA324PA-PU/ATMEGA324PA-PU-ND/2050988

 

(there is a 324PB but I don't believe you can get it in DIP).

 

Another view of the same thing:

 

https://www.arrow.com/en/categories/microcontrollers-and-processors/avr-microcontrollers?filters=USART:2|3|4|5;UART:2|4|5;Supplier+Package:PDIP%20W|PDIP;&promoGroupLevel=pl

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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 05:42 PM (Reply to #7)
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Wow a LOT of pins!
Nice and yes the recomendation I do think was pb. I think my deviation came from not finding DIP. THANKS again. Will check price and prob buy. ( and try not to step on it :) )

Last Edited: Tue. Oct 22, 2019 - 05:43 PM
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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 05:47 PM (Reply to #6)
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Good thinking unfortunately my hands most days have problem soldering Dip, wont fixit with surfacemount

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gechxx
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Posted by gechxx: Tue. Oct 22, 2019 - 05:50 PM
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But ! All links gave pa at best. Javnt yet verif pa has 2.

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westfw
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Posted by westfw: Tue. Oct 22, 2019 - 06:09 PM
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Atmega4809 has a 40pin dip version, and more than two UARTs...

Alternately, pololu (possibly among others) does an atmega328pb arduino-mini derivative, pretty cheap.

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m.majid
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Posted by m.majid: Tue. Oct 22, 2019 - 06:11 PM
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Recently I have similar requirements 2 UARTs for a master device.
1 Connected to some slave devices (250kbps)
2nd as user interface connected to PC (115200bps)
.
mega324P offers 2x UART with 3x price compared to mega328PB (TQFP32)
.
I hope to implement PC side by software via a free port of mega328P
Otherwise mega328PB seems a good choice.

Majid

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Gold Markclawson
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Posted by clawson: Tue. Oct 22, 2019 - 06:25 PM
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People only care about chip price when buying 100s, 1,000s or even more. If you are only buying one chip what does it matter whether it is $1, $5 or $10?

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