- Water heater includes: electricity supply 5v 2a, Arduino pro mini, Nrf24l01, relay 5v30a*4, BUZZER.

The device uses 4 5v30a relay. 2 relay on or off for 1 wire.

The default is to turn on, when starting to power up Water heater.

Water heater can turn on / off manually, so do not write data on / off to EEprom.

Because relay to turn on / off the large electricity(Cause strong electromagnetic waves), should 328p chips crashes. I temporarily processed by: using 2 chips. If 1 chips is crashes then the other chip will handle. The normal chip, will restart the chip crashes and return value to it. That way, it gave pretty good results.