what is the host commands via I2C to configure the charger at five states
one: charging the battery only vout=0 .
Two: charging while the system is working vout ~ 4v 3A vin=5v A=1 to 3A .
Three: vin=5v 3A vout ~ 4v 3A power the system with out battery
four : power the system with battery only vout ~ 4v 3A
five : power down the system vout=0 with and with out vin or battery
