PHAG - A Microprocessor Based Tide Gauge

The design of a low power portable hydrographic water level gauge system (PHAG) is constrained by enviromental, operational, and measurement requirements. The data acquisition electronics provide optimum use of available power at temperatures ranging below C. The hardware and software provide half-duplex RF telemetry and data transfer by solid state cartridge or audio mag-tape. The water level measurement includes an analogue pressure sensor or digital absolute encoder driven by a float. A major feature of the design is the power saving by program control of operation time of all electronics and external circuits. Using these criteria including availability, the CMOS 6502 microprocessor is the best solution for the task.