I bought header connectors (male and female) from Sparkfun and they don’t fit well. The male pins mount flush on the Cobra board but the female connectors are just a tiny bit wider so they cause the male pins to separate and bend. Does anybody have another source like DigiKey or Mouser for header connectors? Here is what the Sparkfun ones look like. I actually prefer ones where you can plug a two connector female into a four connector male. These Sparkfun ones do not allow that.
Depending on what you’re trying to achieve, you can use the male pins on the Cobra 2 and use a standard flat ribbon cable (usually on a 2-wide plug) 0.1" header, like an old IDE hard drive cable. But you will not get full coverage of all pins since there will be extra room at the edges.
Also check out Samtec who can offer you free samples (if you have a company to send them to) or they do nice low volume on them. You can then get the full 41 pin header and socket for it.
I use the stacking connectors so that I can plug in the Cobra 2 to a custom board which then has all the headers and other needed circuitry etc.
For some projects I just put the socket on the Cobra 2 and then use wires soldering onto the header pins with heat shrink. Works well.
Interesting, I just checked other different polarized friction connectors I have on an older FEZ board and the female connectors are also a tiny bit wider than the male connectors, thus not allowing the female connectors to be plugged in side by side. Any ideas as to why this is?
And so it looks like using polarized friction connectors on the 41 pin header is a bad idea. But I really like separating pin functionality into their own connector sets (eg. CAN2 TD and RD, the last two pins on the 41 pin connector, followed by COM4 TX and RX, followed by COM1 TX and RX, and so forth).
But unless I can find polarized friction connectors that will work, I’ll probably just use standard Arduino style connectors. Any preference on male or female on the Cobra? I’m thinking that female would be better since that would allow me to plug in a bare wire for quick testing.
I would like a keyed solution too, but for such a connector I tend to think that it’s probably overkill (it’s not going to be used often).
If you’re direct prototyping like you say, then yes a female+male header combo is likely a great middle-ground. I don’t have a personal preference whether to use a female or male strip on the mainboard, because I tend to use different breadboard wires to connect directly to those when I’m prototyping. If I use a female header on the mainboard, I use male-male breadboard wires, and if I use male header I have male-female wires. I actually bought a really great set of wires with great square DuPont connectors on that makes this easy - something like http://www.ebay.com.au/itm/20-Pieces-Male-Female-Breadboard-Jumper-Cable-Hookup-Wire-300mm-M-F-1P-1P-/120991003981?pt=AU_B_I_Electrical_Test_Equipment&hash=item1c2ba0354d