We need some EE design assistance with a very small project. There are two small sub-circuit functions we have to implement in an existing product.
Both sub circuits will provide an input to a TI MSP430 microcontroller running at 3.3V. SMT components will be used.
Circuit 1: Line voltage measurement. 0-300 VAC input isolated with the output going into an A/D converter in the MPS430. 1500VAC isolation and noise filtering required. Accuracy and linearity especially at 240VAC required. Prefer a design with passive components only. No ICs
Circuit 2: Water presence detector. When an external sensor (small PCB with traces as the probe) gets wet, the circuits output raises an MPS430 input pin from low to high. 12VDC is available. Prefer a design with passive components and simple transistors only. No ICs
Schematic and BOM are the deliverables