Here is a close up of mini-breakout and the connector that mates with the one on the Edison module. The pins on the mini-breakout are labeled
so if we extrapolate that data, pin 1 on the module is below
Edited: Jan 27 2015 - Now correctly shows that corner pins (on the Edison module) are not signal pins
One thing to note is that while the connector on the Edison module appears to have 74 pins (70 pins + 4 corner pins that attach the connector to the module), the mating connector does indeed only have 70 contacts.
Maybe a stupid question: You labeled Pin 1 on the far bottom right. If I count the Pins I get 37 per side -> 37*2=74 in total instead of the 70 Pins from the documentation? The same applies in this image from sparkfun:
I count 37 Pins per side, whereas the first two and the last two Pins are unused.
Am I doing a mistake here, or do I have to skip the first two pins If I want to create my own hardware?
It appears you are correct, looking at the data sheet for the DF40C-70DP connector, it does look like the 4 corner pins (of which there are 74 total) are used as mechanical attachment points and not signal pins. Quote from the connector data sheet:
"Each one contact at 4 corners shall be used as metal hold down"
when I made the image I went by a combination of "extrapolation" and what the hardware guide said (which, in light of these details, is somewhat misleading):
"The location for pin 1 of the 70-pin connector is the lower right corner of the connector. The location of pin 2 is
across the connector at the lower left corner. Consequently, the location of pin 69 is the upper right corner of the
connector and the location of pin 70 is the upper left corner of the connector"
I have corrected my image to reflect what is shown in Sparkfun's edison-pinout image.
One thing to note is that while the connector on the Edison module appears to have 74 pins, the mating connector does indeed only have 70 contacts