PWM and LED Bar Graph

[BeanieBots]

Fortunately, your MOSFET requirements are not very severe so just about any logic level type will do. The one advised by boriz should be fine but might be a little overkill for your app. If you have one, fine, use it. If you need to buy one, then go for lower spec and save a little expense.

Believe it or not, one with a slightly LOWER current rating is likely to run cooler if driven direct from a PICAXE rather than with a proper driver. This is because lower current (and voltage) devices have less gate capacitance and thus turn on/off quicker.

I'd use an IRF520. Why, because I have a few and it would do the job. It also happens to be the one used on the PICAXE high power project board and is also very cheap and readily available.

 

[Dippy]

Setting PWM duty manually reuqires manipulating the registers, like this example.

Assuming we have fDuty as the duty value:
CCP1CON.5 = fDuty.bit1
CCP1CON.4 = fDuty.bit0
CCPR1L = fDuty >> 2

I'm not sure whether that applies to all PICs but at least it start your ball rolling.
You'll have to read the PIC Data Sheet to see the register number.