On Sun, Nov 6, 2016 at 8:20 PM, Bob Ammerman wrote: > So, with a low enough clock rate, you can probably do without the > certification. However, note that even though certification is not > required, > the FCC can still shut you down if your device interferes with others. > Thanks for the advice. There's no particular advantage to a fast clock on this device so I'd almost certainly be using a low clock rate simply for power consumption reasons - though meeting the FCC exemption seems like another good reason. I'm well aware of anti-interference requirements - used to work in radio comms and at one point I sat on a committee investigating interference. Though with a low enough clock that should also be a complete non issue. I am in the UK, but if these meet FCC specs then they should also meet OFCOM and CE specs - I will check. In any case whilst their primary use will be in the UK, the trackers are actually in Australia at the moment and there's a good chance they'll get used in the US at some point. Chris --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .