The latest firmware does store some additional information for each
tank. Right now it's not really used for anything yet, but it's
available for future use.
Due to the integer promotion rules of the C language, the unsigned char
values are promoted to a signed integer (and not an unsigned integer)
before being shifted. But the result of a left shift on a signed type is
undefined if the resulting value can't be represented in the signed
type.
GCC's Undefined Behavior Sanitizer (ubsan), enabled with the option
-fsanitize=undefined, detects this type of problem at runtime with the
following warning: "left shift of X by Y places cannot be represented in
type 'int'".
Fixed with an explicit cast to unsigned integer.
This adds support for older Cochran Commander dive computers,
specifically Commanders with serial numbers prior to 21000.
This also renames "Commander" model to "Commander II" and
adds "Commander I" to refer to pre-21000 models.
The devinfo event with the device serial number is required for the
fingerprint feature. Without this event, applications won't be able to
load (or save) the correct fingerprint. All necessary information is
already available in the initial handshake packet.
The Tusa IQ-700 is very similar to the other Seiko based models. The
most important change is that due the smaller amount of memory (8K vs
32K), the logbook entries are only 1 byte large instead of two bytes.
Some devices do not appear to set the ringbuffer pointers to their
normal empty values (e.g. pointing outside the ringbuffer memory). In
that case, there appears to be a single entry. But since that entry
contains uninitialized memory (e.g. all 0xFF bytes), we are able to
detect this special situation.
