Searching \ for '[EE] Suggestion for 3.3V PIC to 5V device?' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'Suggestion for 3.3V PIC to 5V device?'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Suggestion for 3.3V PIC to 5V device?'
2012\06\06@194133 by Marcel Duchamp

picon face
Looking for a 1-to-8 mux that will run from a 3.3V PIC32.  It will be driving servo signals. It looks like a '595 is just out of range to reliably work.


Any suggestions

2012\06\06@195929 by Dwayne Reid

flavicon
face
At 05:41 PM 6/6/2012, Marcel Duchamp wrote:
>Looking for a 1-to-8 mux that will run from a 3.3V PIC32.  It will be
>driving servo signals. It looks like a '595 is just out of range to
>reliably work.

Umm . . . '595' to me is a shift register.  If you need a 1:8 mux, I'm certain that a 4051 is rated from 3.0 to 15 Vdc.

dwayne

-- Dwayne Reid   <spam_OUTdwaynerTakeThisOuTspamplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2012\06\06@201811 by Marcel Duchamp

picon face
On 6/6/2012 4:59 PM, Dwayne Reid wrote:
> At 05:41 PM 6/6/2012, Marcel Duchamp wrote:
>> Looking for a 1-to-8 mux that will run from a 3.3V PIC32.  It will be
>> driving servo signals. It looks like a '595 is just out of range to
>> reliably work.
> Umm . . . '595' to me is a shift register.  If you need a 1:8 mux,
> I'm certain that a 4051 is rated from 3.0 to 15 Vdc.
>
> dwayne
>
Thanks.  Yeah, I just figured that one out, too. It's late..

2012\06\06@211041 by Isaac Marino Bavaresco

flavicon
face
Em 6/6/2012 20:41, Marcel Duchamp escreveu:
> Looking for a 1-to-8 mux that will run from a 3.3V PIC32.  It will be
> driving servo signals. It looks like a '595 is just out of range to
> reliably work.
>
>
> Any suggestions?


You are in the right path. You can use a 74HCT or 74AHCT device powered
by 5V. Its inputs will understand the 3.3V CMOS outputs
Fill a shift-register with zeros then walk a single '1' across all the
outputs, waiting the necessary pulse width for each output. Repeat every
20ms.
It takes just 2 I/Os, clock and data. The chain can have up to 10
outputs and yet ensure correct timing for all the servos (2ms x 10 = 20ms).

Isaac

2012\06\06@221214 by Matt Bennett
flavicon
face
On Wed, June 6, 2012 8:10 pm, Isaac Marino Bavaresco wrote:
> Em 6/6/2012 20:41, Marcel Duchamp escreveu:
>> Looking for a 1-to-8 mux that will run from a 3.3V PIC32.  It will be
>> driving servo signals. It looks like a '595 is just out of range to
>> reliably work.
>>
>>
>> Any suggestions?
>
>
> You are in the right path. You can use a 74HCT or 74AHCT device powered
> by 5V. Its inputs will understand the 3.3V CMOS outputs
> Fill a shift-register with zeros then walk a single '1' across all the
> outputs, waiting the necessary pulse width for each output. Repeat every
> 20ms.
> It takes just 2 I/Os, clock and data. The chain can have up to 10
> outputs and yet ensure correct timing for all the servos (2ms x 10 =
> 20ms).

The PIC32 has 5V compatible pins- you can pull them up to 5V with an
external resistor and run the I/Os as open drains.  Not as fast as an
active pull-up/pull-down, but definitely cheaper, and probably good enough
for RC servos.

Not all the pins are 5V compatible though, you have to double check on the
data-sheet.



Matt Bennett
Just outside of Austin, TX
30.51,-97.91

The views I express are my own, not that of my employer, a large
multinational corporation that you are familiar with

2012\06\06@232411 by Harold Hallikainen

face
flavicon
face

>
> You are in the right path. You can use a 74HCT or 74AHCT device powered
> by 5V. Its inputs will understand the 3.3V CMOS outputs

I use the HCT trick all the time! Works great!

Harold



-- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising
opportunities available!
Not sent from an iPhone

More... (looser matching)
- Last day of these posts
- In 2012 , 2013 only
- Today
- New search...