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Topic: Exact pin space D7-D8: Mega vs Duemilanove (Read 1 time) previous topic - next topic

QwertyMos

Hi,
in description of Arduino Mega I see that "distance between digital pins 7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing of the other pins"
There are same words in Duemilanove description.
I check Eagle files for Duemilanove. Yes, pin space D7-D8 is 160 mil.
But, in Eagle files for Mega I see pin space D7-D8 only 150 mil.
Is it bug? What is right pin space D7-D8 for Mega?
Of course, 'right space" IMHO should be x100 mil to be compatible with breadboards, but why Mega layout have 150 mil instead of 160 mil?
Please clarify.

Thanks.

macegr

Over the next 10 years, they will gradually move the spacing back to a 0.1 grid!
Unique RGB LED Modules and Arduino shields: http://www.macetech.com/store

retrolefty

Quote
Over the next 10 years, they will gradually move the spacing back to a 0.1 grid!


LOL, we can call it the Italian method!

Lefty


ahdavidson

Watch it! :-)

I don't think it's just the Italians -- after all, over on this side of the pond we're still dealing with NTSC television and QWERTY keyboards, just to name a few ancient immovable standards.
.andy

QwertyMos

Ok, "...will be .. move ... to 0.1 grid". Excellent!!!
However, first question - 0.1 grid is 100 mil or 200 mil or ...?  ;)
second - starting from what date WILL BE?  ;)
third - what WILL be with a lot of current "wrong space" shields?

Still main question - what is CURRENT exact (real) space between D7 and D8.

Thanks!

retrolefty

Quote
Still main question - what is CURRENT exact (real) space between D7 and D8.


I forget, but if expressed in inches it uses a lot of digits to the right of the decimal point.  :D

Lefty

QwertyMos

Let's express in mils. If you switch grid in Eagle from mm or inches to mils, you will see what I am asking about.
D7-D8 space from Eagle files:
- Arduino Duemilanove = 160 mils
- Arduino Mega = 150 mils
- Ladyada.net shields  = 155 mils

Think, if I will make PCB from these files, my boards will be incompatible...  :'(

pluggy

#7
Oct 03, 2009, 09:34 am Last Edit: Oct 03, 2009, 09:40 am by stephen_t Reason: 1
In reality you can probably easily 'spring' the pins if they are only 0.01 inches out.  Quarter of a millimetre is neither here nor there. Pity the same can't be said about .05 inches, then the initial 'cock up' wouldn't matter :)
I have a cheap Arduino clone from Hong Kong, and the shield fit wasn't as 'nice' as a real one.  Once I'd plugged it in and out a couple of times it 'adjusted' itself.
http://pluggy.is-a-geek.com/index.html

QwertyMos

And what about original Mega and Duemilanove?
Is it really have 10 mil difference for D7-D8 or it's just "bug for clones" in Eagle files? ;)

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