OBS500 Firmware

Resolved an issue where current drain was not dropping to 200uA after the aM! and aM2! SDI-12 commands were issued. The current drain would drop only to 4mA. If the aM3! Command was issued followed by aM4! command, the current would then drop to the correct 200uA quiescent current.

Changed the default SDI-12 address from "1" to "0".

Increased the SDI-12 time declared in the "attn" response to the "M" and "C" commands to include the time to close the shutter after a measurement is completed.

Added leak protection response to shutter control functions. If a leak is detected the shutter shaft rotations are halted after the shutter is moved to an open position.

Added changes to the sdi-12 "M" and "C" commands to reduce the shutter open and close cycles.

Added SDI-12 Burst Measurements of raw turbidity voltages.

Increased SDI-12 usable addresses from the standard ASCII "0" through ASCII "9" to ASCII 'A' through ASCII 'Z' and ASCII 'a' through ASCII 'z'.