Hi,
I am planning to connect my cc2540/nrf51822 modules to 2.54 mm header, so that prototyping via bread board would be easy.
Could any one point me to eagle-libraries or any other useful links
Thanks in advance
mahadevan
For starters our library has the standard .1" headers in it. We also have an eagle tutorial for creating footprints, So try and make them yourself.
Here are our usefull eagle tips: http://dangerousprototypes.com/docs/Dan ... soft_Eagle (http://dangerousprototypes.com/docs/Dangerous_Prototypes_Tutorials#Cadsoft_Eagle)
Yeah, I'm not sure quite what your question is either, as it sounds like you are just making a tiny board to breakout a smaller header to a bigger header, and well, a pcb doesn't get much easier than that, but I wanted to point out a little header trick I like.
I found this "sneaky-headers" note on sparkfun:
https://www.sparkfun.com/tutorials/114 (https://www.sparkfun.com/tutorials/114)
And I thought to myself "how bloody obvious; why has nobody done this before." And then I got a dev board from microchip that had the same offset trick on the ICSP header. Huh!
So I tried it myself: for a 6-pin 0.1" SIP ICSP header footprint, I offset alternating pins outwards by 5-mil. I use 50-mil pads with 35-mil holes. I put a 6-pin male-to-male 25-mil-square header strip in my Pickit3, and it bites nicely into the pads for programming; no connector required. Also will work great for retention during soldering of 25-mil-square SIP headers or sockets for an arduino shield or something, so they stay in place when you flip the board over for hand soldering, as the sparkfun fellow pointed out (some sparkfun sip sockets are not 25-mil-square, BTW, so be careful).
For dual-row 0.1" headers (10, 20, and 34 pin), I thought it overkill to offset every pin, as I just wanted them to sit still when the board is flipped for soldering, so I offset the two pads on each end sideways (lengthwise) by 5-mil, and it worked frickin' beautifully. Header presses in easily, and stays in place when flipped. Just offsetting the outer 4 pads was enough -- offsetting all of them (in the shorter dimension) would have made larger headers harder to insert.
This is all at the mercy of how accurate your pcb house is in maintaining the specified interior diameter of a finished plated hole, which can vary a lot, so we generally use a 35-mil or so finished hole for a 25-mil-square pin (with a diagonal of 35 mil), and it is often loose. Tweaking a few pads fixes that, not just to help with hand soldering, but also for retention when a board is run over a wave.
gil