I need a electronic circuit powered by a small battery (i.e. CR3032) witch powers two timers. One should start, when the power button of the circuit is pressed and give an ongoing signal, when 30 days are over. The other timer should react on a passing hand (like ir-reflection on a water faucet) and give a short beep after 30seconds. The whole circuit should use cheap parts and does not need to last more than several months. The size of whole circuit should not exceed 4cm in diameter / 4x4cm in square. The smaller the better. Price of the circuit is critical, so microprocessor boards should not be used. The Project should include the Circuit, PCB layout, bill of materials and Eagle Files.
23 freelancers estão ofertando em média €141 para esse trabalho
I will provide you with an extremely low cost but quite precise timer circuit that doesn't make use of any RTC chips that increase cost. You will be able to fine tune the circuit by using the trimpot.