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Topic: More Serial ports! (Read 4136 times) previous topic - next topic

CrossRoads

Mar 06, 2011, 06:00 am Last Edit: Mar 06, 2011, 06:03 am by CrossRoads Reason: 1
Just got word of this part from maxim-ic.com:

MAX14830
Quad Serial UART with 128-Word FIFOs and Internal Oscillator

Industry's First Quad UART
Scalable solution for industrial applications that is ideal for high channel count systems with the flexibility of adding channels
Simplified IO-link for master systems with the ability to synchronize the start of selectable UART's transmission by SPI™/I²C global commands
Works with up to four master IO-link PHY layer MAX14824s

I have a sample of single UART chip, MAX3100 in DIP, that I am looking forward to trying out via its SPI interface.
http://www.maxim-ic.com/datasheet/index.mvp/id/1731/t/al

I think I may be waiting on a 3.6864MHz Crystal for it, or it came already and I misplaced it.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Graynomad

That quad sounds nice, I'll have to think of a project that needs one :)

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

CrossRoads

Check the data sheet, they have recommended some parts to go with it for serial port level drivers for lack of a better term.
Not available as samples yet tho, and only in 48 TQFN package.
http://datasheets.maxim-ic.com/en/ds/MAX14830.pdf  1-4MHz crystal. 1.8MHz only specific callout I saw.
The 128 word buffer per UART should make for smooth software operation I would think (vs sucking up a bunch of atmega RAM).
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Graynomad

Very nice, pity about the package, I'm getting better at soldering SMDs but that might be a problem.

_____
Rob
Rob Gray aka the GRAYnomad www.robgray.com

CrossRoads

http://pdfserv.maxim-ic.com/land_patterns/90-0129.PDF

Yes, 0.5mm pad spacing is a little tight.

Could get an adapter like this
http://www.dipmicro.com/store/PCB-LQFP48-DIP48G
even gets you pads for a crystal and caps to make a little unit out of it.

Order a few other items at the same time to get to $10 and get 10% disount too.

Got a friend who could mount it for you?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Graynomad

#5
Mar 06, 2011, 03:44 pm Last Edit: Mar 06, 2011, 03:49 pm by Graynomad Reason: 1
Quote
Got a friend who could mount it for you?

No rush, I think I have enough projects on the go right now.

EDIT:
Actually now that I think about it, I made a plug-in board for a popular Z80-basedcomputer in the 80s. This computer had no real serial ports just bit-banged serial, so my board replaced the processor with a PCB that relocated the Z80 and added an SIO to give two UARTS and an RTC. Maybe an equivelent for a 328-based Arduino wouldn't be a bad idea.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

Alvaro

With ZPUino (http://www.alvie.com/zpuino) you can have as many serial ports as you wish (however you might need to reduce UART receive fifo, if not enough memory on FPGA).

Álvaro

CrossRoads

and zpuino maybe even procurable some day? I don't see any place to order.
Think I will go simpler route for now: max3100 in dip package, add one for each extra serial port needed.
Only 8 word FIFO, need to write some code I guess.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Brad Burleson


Think I will go simpler route for now: max3100 in dip package, add one for each extra serial port needed.
Only 8 word FIFO, need to write some code I guess.


My only problem is how expensive these are.  I know you can get samples, but did you see the price is $8 each (qty 1), and you have to buy over 100 to get the price less than $5 each?

I'm tempted to simply add an ATMEGA168 (price each $3.33 at qty 1) for the ultimate "extra" UART. 

With, as you note, a bit of coding.

Just a thought.

Brad.

CrossRoads

Geez, how does Maxim expect to sell things?
Yeah, those are expensive.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

diego2308

Yes i wonder if it were possible that in a future the cheap versions of arduino wuold have a bit more uarts and PWM

Graynomad

I wish there was a tiny85/84 equivalent with a UART.

I won't be holding my breath though.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

CrossRoads

If MAXIM can offer a whole ATMega328 with a UART for <$6, why can't  a standalone UART be offered for even less? Makes  you wonder ...
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Cynar

Quote
If MAXIM can offer a whole ATMega328 with a UART for <$6, why can't  a standalone UART be offered for even less? Makes  you wonder ...


Economies of scale. They can roll out 328s by the thousand and know they'll sell them. A UART adapter is a more niche item, and so have a more niche price tag.

kg4wsv

Quote
Very nice, pity about the package, I'm getting better at soldering SMDs but that might be a problem.

Check out the MAX3110.

-j

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