I've been tasked with recreating a device that outputs selectable tones via two loud speakers (home alarm siren type). The device will be enclosed in a box and attached to a floating buoy. When turned out it will simply emit a tone consistently. The original design used a 12V battery that could be recharged. Also the original design used what appears to be NE555 Timer chips. Are these used to generate the pulses?
While in my head the concept seems simple, I am concerned with a few items. #1 - How should I power the speakers? Surely an Arduino with a 9V battery will be insufficient? #2 - how to set tones? Using a toggle switch? #3 - is Arduino a good solution for this?
See images of the existing circuity and PCB. Any guidance here is appreciated.