[Deetman]

I don't want to point fingers at the D-Link directly with this post merely point out a few common thoughts that have been thrown around.

1) Perhaps the biggest problem anyone has in pinning any root cause down is that no two robots are alike. For that matter, not every team is running the same D-Link AP. There are multiple hardware revisions floating around out there and multiple firmware versions as well. Thus is the nature of not having full control of a commercial product. Even the same "version" of a D-Link AP may vary with quality control issues (bad solder joints, loose connections, DOA components) and parts are often substituted in due to obsolescence, cost, and availability issues. One of the first things you learn as an engineer when troubleshooting is to control the variables and only change one thing at a time. FIRST cannot do this with the D-Link as teams can get them from anywhere as long as they are the DAP-1522. Some vendors have old stock with old revisions, some with new stock, etc. Revisions to hardware/software are not made "just because". Usually there is a distinct defect that is being addressed in a revision. Theoretically a DAP-1522 is a DAP-1522 but even a small change could have a disastrous effect in obscure use cases.

2) After watching the webcast yesterday I went off in search of some more obscure info on the D-Link DAP-1522. I had considered this before as the issues throughout the season piqued my interest. The most interesting things I found were some nice pictures of the D-Link's internals. There were three things I noticed:

• Save bad or weak solder joints, nothing about the design or mounting screamed out to me as being horrible with respect to the harsh mechanical environment we subject the D-Link to.
• There are multiple revisions of the hardware out in the wild. See the pictures below. One version does not have the RF connectors glued, another does.
• The u.fl connectors to the antenna seem to be the most likely point of mechanical shock/vibration failures. It appears that this concern would be addressed with the glued hardware. I've never used a u.fl connector, but it does seem like a pretty unreliable physical connection given what these APs may be subject to on the robot. These things are only 2mm tall!