Is the 12C SDK still available?

[Katie Wasserman]

Lot's of questions.........

- The latest 12 (regular) with the SAM4LC2CA chip still uses 2 CR2032 cells in parallel and the physical case is indistinguishable from the prior Atmel version.

- The SAM4LC2CA version is slightly faster than the prior version, I measured about 10% faster, not as much as a 48MHz to 32MHz clock rate would indicate.

- Current draw is arguably improved, rough measurements are:

Code:


                   OLD          NEW
OFF               3.5uA        1.0uA
ON                47 uA       120 uA
KEY DOWN         550 uA       120 uA
RUNNING           21 mA        13 mA

The running current was what killed the low battery functionality previously. The ON current has doubled on the new version, so it's sort of a tradeoff, but I think for the better.

- Low battery indicator works better on the new version. The trigger point seems to be about 2.5 volts and this is tested every 30 key presses (or so). However it still might fail if the internal resistance of the CR2032 cells gets too high.

- In my sample, the back plate is printed slightly differently on the latest version. But I don't know if this is significant as this might change often between batch runs.