I have bi-colour LED's on my board that have about 2.2 volts across them 
when there's 25 mA flowing through them.

I'm thinking of using a single 1.5 volt AA battery to power my board.

I've got two questions:

1) Can I go straight from the 1.5 V battery into the LED's without a 
current-limiting resistor?
2) What kind of regulator should I use to provide my uC with 5 volts?

Very little current will be drawn from my uC's output pins because all 
the output pins go straight into driver chips, so this can be taken into 
account when choosing a regulator. Something small and cheap to step 1.5 
volts up to 5 volts.

My uC is the 887.

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