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Topic: Arduino Header Alignment Anomaly: Another Workaround (Read 2119 times) previous topic - next topic

kiwimew

After bread-boarding my first Arduino project I decided it was time to make it more real.  I got myself a nice little perf board, some header strips and started playing around with them.  Imagine my shock at finding that a strip of 16 pins at the standard 0.1" spacing wouldn't mate with the sockets on the right hand (digital) side of my Arduino.  Initially I thought I had a bad board but a bit of googlin' revealed that this is a known issue.  It's mentioned as the very last sentence here http://arduino.cc/en/Main/ArduinoBoardUno but I had somehow missed it  :P

I have a relatively simple solution which lets me mate a standard perf board to an Arduino.

The key is to use a strip of right-angle header pins in addition to the in-line ones.  For the digital side, take a strip of 16 right-angle headers and two strips of 8 in-line headers.  Fit the in-line's against the right-angle's as shown.

Arduino Header - Rendering by funnypolynomial, on Flickr

Arduino Header -- Gap Detail by funnypolynomial, on Flickr

Arduino Header -- Mated by funnypolynomial, on Flickr

Solder one bank of 8 with its pins touching the left-hand side of the angled header pins, and the other bank touching the right hand side.  This trick introduces an additional gap between the two banks equal to twice the pin width or 0.05", giving an offset of 0.15".  This is very slightly less than the "official" gap of 0.16" but there seems to be enough play in the sockets for it not to matter.

The analog-side strip is made in a similar way, except that all angled and in-line pins need to touch on the same side (the left, to be consistent with the digital strip).

The nett effect is two strips of pins which can be soldered into a standard 0.1"x0.1" gridded perf board and the whole unit can be mated to the Arduino. 

A few things to note:

  • yes, it does make the board sit a little higher

  • the strips can be attached to either side of the perf-board (you can solder on the same side, or the other side)

  • it's probably a good idea to snip the unused long pins off the right-angled header

  • also a good idea to shorten the short pins on the in-line header

  • take care when soldering the strip together not to let the solder bleed down the leg too far or you may have trouble getting it through the perf-board holes



A few more photos on flickr, http://www.flickr.com/photos/funnypolynomial/sets/72157627320381707/
That first project is on hold until I find a suitable housing  :)
There are a few other solutions out there; drilling extra holes, bending pins (SparkFun sells this, http://www.sparkfun.com/products/9374)
But I think this method is a little more repeatable (and robust).
// TODO: sig


retrolefty

#2
Aug 22, 2011, 07:50 pm Last Edit: Aug 22, 2011, 07:53 pm by retrolefty Reason: 1
Nice work. In the future you might want to look at using these:

To handle the 'offset' connector:

8 pin http://www.sparkfun.com/products/9374

For the other connectors:

6 pin http://www.sparkfun.com/products/9280
8 pin http://www.sparkfun.com/products/9279

Lefty

kiwimew

Thanks Lefty, I'm aware of sparkfun's product (and included a link in my original post) but I think my approach has advantages -- standard components, headers on either side of the board, etc
// TODO: sig

mmcp42

of course there is in fact a positive advantage in having "misaligned" connectors
you can't plug a shield in the wrong way round!
there are only 10 types of people
them that understands binary
and them that doesn't

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