That product and the weird discussion below it set met on the trail to find out 
how it worked. Sparkfun doesn't realize it works bi-directional. Their voltage 
dividers (on the same board!) are superfluous. 

http://www.sparkfun.com/products/8745



Sent from my iPhone

On 28 mrt. 2012, at 17:35, Joep Suijs <[email protected]> wrote:

> It does work well indeed. Sparkfun has a compact implementation of
> this: http://www.sparkfun.com/products/8745
> 
> Joep
> 
> 2012/3/28 Eur van Andel <[email protected]>:
>> Hi all
>> 
>> This is hardware related, but someone might use it.
>> 
>> Modern sensors and IC's are most often 3V3 instead of 5V. Some other (older)
>> peripherals are 5V only. The power supply is easy, but the databus is
>> harder.
>> What we need is a 3V3 <-> 5V bi-directional level shifter.
>> 
>> These are for sale, off course:
>> 
>> http://nl.farnell.com/nxp/pca9306d-118/ic-i2c-bus-smbus-level-xlator-soic/dp/1831194
>> 
>> but are expensive, not available or both.
>> 
>> This is a much simpler solution, just two pull-ups and a MOSFET transistor:
>> 
>> http://www.rocketnumbernine.com/2009/04/10/5v-33v-bidirectional-level-converter
>> 
>> Be sure to check out the original document here:
>> 
>> http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf
>> 
>> By Herman Schutte, the father of the I2C bus.
>> 
>> I have tried it, and yes: it works.
>> 
>> 
>> ---
>> 
>> ir EE van Andel [email protected]  http://www.fiwihex.nl
>> 
>> Fiwihex B.V. Wierdensestraat 74, NL7604BK Almelo, Netherlands
>> 
>> tel+31-546-491106 fax+31-546-491107
>> 
>> 
>> 
>> --
>> You received this message because you are subscribed to the Google Groups
>> "jallib" group.
>> To post to this group, send email to [email protected].
>> To unsubscribe from this group, send email to
>> [email protected].
>> For more options, visit this group at
>> http://groups.google.com/group/jallib?hl=en.
> 
> -- 
> You received this message because you are subscribed to the Google Groups 
> "jallib" group.
> To post to this group, send email to [email protected].
> To unsubscribe from this group, send email to 
> [email protected].
> For more options, visit this group at 
> http://groups.google.com/group/jallib?hl=en.
> 
> 

-- 
You received this message because you are subscribed to the Google Groups 
"jallib" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/jallib?hl=en.

Reply via email to