I haven't been able to post in quite a while - far too many things in real life distracting me. But now that I have gotten back to hobby time, I am expanding my system with an I2C interfaced GPIO extender. Everything worked great on the workbench, but refused to work at all once installed. It appeared that the bi-directional buffer chip that I used to connect the Pi to I2C wasn't working, which made no sense.
I broke down and pulled the interface board down and brought it to the workbench. Under the magnifier, the problem was immediately obvious.
Soldering is an art. It takes practice, and I was terribly out of practice when I started this blog (and made this board.) Bottom line, the SDA and SCL lines were shorted by some over-zealous soldering. Since I hadn't used I2C, it was never a problem.
I have a feeling I am going to replace this board with a completely re-designed version before too long.
Ted,
ReplyDeleteNew solder would go a long way to preventing this. The flux core only has about a 3-year shelf life. May I suggest Kester - No-Clean 245 Solder Wire, .031" dia., Core Size-66 Sn63Pb37. This size and formulation of solder works great for me. And I thought it was my soldering skills that were deteriorating...
I remember you mentioning that last time we met. I will get some new solder before I do any more building.
DeleteStill working on the sprinkler interface. Hope to have a post up on that soon.
Hi! I work with engineering website EEWeb.com and would love to do an exchange of website links and feature you as a site of the day on EEWeb (you can see an example here http://www.eeweb.com/websites/sparkle-labs/). Is this of interest to you? I can be reached at claire@eeweb.com
ReplyDelete