More Serial ports!

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.

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


Rob

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).

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


Rob

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?

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

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

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.

CrossRoads: 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.

Geez, how does Maxim expect to sell things? Yeah, those are expensive.

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

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

I won't be holding my breath though.


Rob

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 …

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.

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

Check out the MAX3110.

-j

Nice find - MAX3100 & MAX3232 combined into one package, along with the 10uF caps needed to make +/-10V outputs.

I’ve got a shield built, but never have gotten around to writing any code. :expressionless:

In spite of the partially complete MAX3100 project, I’ve come to the same conclusion as others - using an Atmel chip would be cheaper. The code has to be written on both ends, though. At least on the MAX3100 half the software is written already. Deciphering it may or may not be easier that writing your own; YMMV. :slight_smile:

along with the 10uF caps needed

The MAX232 IC we all know and love is now commonly found in the 232A variant from most manufacturers, and the A only needs 0.1uF caps. Yeah, OK, it still needs 4 caps, but 0.1uF caps are small and cheap. I’ve had good luck with ceramic SMTs.

-j

Good catch. Yes, 0.1uF, not 10uF. I have those shown on my schematic, had 10uF on the brain for some reason.