I’m using one of the recommended sockets: http://www.digikey.ca/product-search/en?vendor=0&keywords=101-00313-68-02CT-ND
Unfortunately I’m having issues with I2C communication using pins 1 & 2. It seems that the position of the card in the socket is a bit sensitive and can break communication with my I2C devices. This is happening on my only current prototype.
I’m wondering if this is a fluke, and if not, should I switch pins or switch sockets?
There’s well documented information in the forum related to pin 1 intermittencies with some Imps. (I believe they relate to older development Imps … a change to mitigate this problem was introduced along the way at some point).
Perhaps check out this thread …
http://forums.electricimp.com/discussion/1162/no-signal-on-scl-pin-1#Item_8
Several folks have reported the problem you’re observing. (I’ve personally encountered it, with the same Amphenol socket you’re using). The solution Imp has suggested in the past has been to contact them for a possible swap out of suspected devices. I did swap out a couple of my devices at one point, (retaining the Amphenol socket), and the problem went away.
Thank you for the reply, Larry. I remember reading about the Sparkfun April board having the same issue. However I thought they used a different socket.
So I’m still wondering if I would be better off switching my I2C pins to 8&9, or looking at a different socket.
The problem doesn’t happen with the Proconn sockets that all the imp devices use (these are the ones that are on the Adafruit april too). If you’re seeing it then we can swap out your imp for one without the issue.
Yes, I should have emphasized the issue (and my experience) is related only to the imp/Amphenol combination. Re: Proconn, it’s been quite a while since I selected a socket, but it appears the Proconn is now available (in small quantities) from Sparkfun … https://www.sparkfun.com/products/11362. Good to see. (Maybe it’s been there and I’ve just overlooked it before). I think I’m going to switch over to this for new designs.
Okay I think I’ll try switching to the Proconn socket, and switch to pins 8 & 9 just to be safe as this is for a commercial product. What distributors carry the Proconn socket (besides Sparkfun)? A product link would be fantastic! I think info existed in the old docs but can’t find it anymore.
Don’t think that socket is Proconn - it’s more likely to be a 4ucon one (proconn ones say proconn on the top housing). This is the one they build their April equivalent with, hence it has the issue.
The safest (and cheapest) option for a commercial product is the module, though 
Hi Hugo, I went with the card over the module for the purpose of modularity in my product line; I will have several products that can run standalone, or connected to each other and sharing a single imp card.
Sooo…where can I get the Proconn sockets? 
Hmm … thanks for clarifying. I guess I’ve been a bit confused too thinking 4ucon = Proconn. So, both Imp-recommended sockets (4ucon and Amphenol) can contribute to the pin 1 intermittences with older imps?
I like to build my own hardware for packaging flexibility, so agree with @spencergs that it would sure be nice to have a source (in my case for smaller quantities) of the Proconn socket.
Proconn don’t appear to be making the socket any more; if you are buying imps (non developer edition) direct from us then they are fine on pin1. It was only early production, which mostly went into developer cards, that really showed the issue.
Hi Hugo,
So just to be crystal clear…
There is no need for me to worry or change I2C pins, as there will not be connection issues with my current socket and current non-developer edition imps. Correct?
Thanks
Spencer
Imps direct from us are definitely fine, yes.