Trying to turn on pro mini 5v with transistor

i put arduino on pcb board , after power saving techniques going sleep, , 3.3v, 8mhz, etc, able bring down power draw 2.5-3.0 ma 4 aa cells in series.

i have nrf24l01 connected , tried use nrf power saving techniques, still  drew 2.5ma.  i removed nrf24l01 radio , power dropped .6ma (may have been lower).

anyway, changing tactic now, instead of arduino being in sleep mode, thinking of keeping off entirely, no loop, needs in setup, external turns off.  this thinking



note have power 5v should 6v

the transistor used 2n2222 maybe should using mosfet, not calculate proper r1 value, electronics foo weak.

also read somewhere base voltage , collector voltage need same,  they not, pir needs powered @ least 5v , signal 3.3v.

anyone have better ideas or thoughts?  the promini 5. nrf24l01 draws 40ma

thanks,
la

circuit should work, try 1k r1. 6v absolute max supply voltage microcontroller. transistor drop couple tenths fresh aa cells deliver bit more 6v. it's close.

the power led on pro mini might account 2.5-3ma current while mcu sleeping. folks remove led low-power projects.

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