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Topic: Beginner's queriesss on I2C Serial Connection (Read 12892 times) previous topic - next topic

nickgammon


I could see a part  like this being handy here, and inexpensive too.

http://www.nkcelectronics.com/logic-level-converter.html


Sigh. Only $1 each. I was about to order 20 of them for future use, until I saw the $60 shipping bill.
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

CrossRoads

$60!  Whooaaa!

Check back with them - USPS has $14 flat rate postage to any country (Canada/Mexico less). See If they'll ship that way.
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.

nickgammon

That was for USPS.

http://ircalc.usps.gov/?country=10013

If you click on "Priority Mail International Large Flat Rate Box" it quotes "Post Office Price $58.50".

But if I go back and choose "Priority MailĀ® International Small Flat Rate Box" it quotes $13.95, which is more reasonable.

I'll try to negotiate with NKC Electronics. They don't offer the smaller package on their automated system.
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

CrossRoads

Yeah, press them on it.
I asked UPS about a shipment to Belgium - they wanted $83!
$14 a lot more reasonable.
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.

wayneft

This should solve your problem.... http://www.dsscircuits.com/i2c-multiplexer.html

It multiplexes the I2C signal and takes care of the logic level conversion at the same time.

CrossRoads

#20
Aug 09, 2011, 12:35 am Last Edit: Aug 09, 2011, 12:40 am by CrossRoads Reason: 1
Yes, that will help out the OP.

PCA9544AD SO20 plastic small outline package; 20 leads; body width 7.5 mm SOT163-1  << this one would be workable for hobbyists.
PCA9544APW TSSOP20 plastic thin shrink small outline package; 20 leads; body width 4.4 mm SOT360-1            <<  0.65mm spacing is hard
PCA9544ABS HVQFN20 plastic thermal enhanced very thin quad flat package; no leads; 20 terminals; body 5 x 5 x 0.85 mm SOT662-1  << 0.65mm spacing is hard

No easy to use DIP package tho. Too bad, drives up the cost. 74LS138 looks pretty good by comparison.

The problem for Nick is that he is in Australia - and shipping costs there are out of control.
Overseas anywhere seems expensive - UPS wanted $83 to send a USPS Small Flat Box to Belgium. USPS Flat Rate to any Country is $14.
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.

wayneft

That's why I also offer First Class International shipping with USPS and it's only $2.72 USD.

CrossRoads

What would it cost to get FT232RL with the 6 programming pins & 2 LEDs & USB-B Mini on a card?
I like the chip, think I'd prefer a module I could glue down then trying to solder that chip for projects. Want it small, will 'tack' on 6 wires to go to pads on a board, so 0.1" pitch pins not needed.
Have been browsing e-bay, I see modules from HK/China for $5-7, but 2-3 weeks for shipping, and not necessarily trace/component free on the bottom.
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.

nickgammon

How about the Foca (FT232RL Tiny Breakout) from Iteadstudio? Costs $8.90 assembled, but you can get the board for $1.50.

Might be a bit large for what you want. Has some traces on the bottom but no components. If you soldered it yourself you wouldn't need the through-board stuff like the connecting pins.
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

nickgammon


That's why I also offer First Class International shipping with USPS and it's only $2.72 USD.


Oh is that you? Just ordered some stuff from you. :)
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

CrossRoads

No, that's too big.
like this
http://cgi.ebay.com/ft232rl-breakout-/260831532714?pt=LH_DefaultDomain_0&hash=item3cbac556aa
but smaller (no pins down the sides, maybe 2x3 header to connect wires to, or just the holes so its flat on the bottom.
Or leave off the components, just add a mini connector with
+5
+3.3
Gnd
Reset
D+
D-
Rx
Tx
DTR
TxLED
RxLED
Gnd

Maybe space at the end for a 2x6, 2mm connecter like this
http://www.nkcelectronics.com/2mm-2x12-pins-female-so2212.html
or a 1x6 at each end.
The kind of connector this thing could plug onto.
http://www.sparkfun.com/products/8732
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.

nickgammon

I suppose you thought of this already, but the dead-bug approach?

http://www.eevblog.com/2011/06/21/eevblog-181-dead-bug-prototype-soldering/
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

nickgammon

28 pin SSOP Adapter, but it isn't much smaller than the other board I suggested:

http://www.futurlec.com.au/SMD_Adapters.jsp
Please post technical questions on the forum, not by personal message. Thanks!

More info: http://www.gammon.com.au/electronics

CrossRoads

I am not delivering finished products with dead bugs. 8) I'm after a reliable deliverable solution that doesn't require a stencil costing 3 times what a batch of boards cost and doesn't require rework of the FT232RL chip.

Like the 28pin SSOP, but overall smaller because fewer connections are needed.
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.

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