Exact pin space D7-D8: Mega vs Duemilanove

Forum 2005-2010 (read only) Hardware Bugs & Suggestions
1

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.

2

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

3

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

4

Watch it! :slight_smile:

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.

5

Ok, "...will be .. move ... to 0.1 grid". Excellent!!!
However, first question - 0.1 grid is 100 mil or 200 mil or ...? :wink:
second - starting from what date WILL BE? :wink:
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!

6

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. :smiley:

Lefty

7

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... :cry:

8

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 :slight_smile:
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.

9

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? :wink: