Pages: [1]   Go Down
Author Topic: pro mini conversion  (Read 765 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 22
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi there,

I'm looking to convert a couple of 5v pro mini's to 3.3v pro mini's.  I figure I'll have to swap the regulators, the bootloaders and the oscillators.  I am just wondering if anyone knows the part number for the 8 mHz oscillators as I can't seem to find a compatible one.

Also I think I found something that might work but it's listed as a resonator in digikey.  But what is the difference between a crytal, an oscillator and a resonator (from a google search it looks like and oscialltor is just a crystal with the control capacitors, but I may be wrong).

Cheers,

Andre
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 538
Posts: 27089
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Why? You're just gonna end up damaging them.

 Go to gravitech.us and buy 2 more, $17.95 each.

http://www.gravitech.us/arpromi3.html
Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Dallas, Texas
Offline Offline
God Member
*****
Karma: 0
Posts: 861
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

if you are thinking about reprogramming the boot loader anyway you might take a look at changing the clock prescaler to divide by two. I'm not sure if that will work since I'm not sure the crystal oscillator will run at 16MHz on 3V3 but it's worth a try since it wouldn't require you to pry anything off the board.

Edit: I'd also look into running it off the internal 8MHz RC oscillator. The accuracy is not that bad depending on your application.
« Last Edit: August 24, 2011, 01:28:27 pm by EmilyJane » Logged

Málaga, Spain
Offline Offline
Edison Member
*
Karma: 41
Posts: 2182
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

The internal clock is a nice option. Depending on the app ofcourse. If you need more precision you can always calibrate it. However, you will end up fluctuating with temperature.

Pros - no moding, change fuses and use an 8Mhz bootloader.
Cons - accuracy, long term stability and temperature drifts.
Logged

   

Pages: [1]   Go Up
Jump to: