Hi
I want to build a little CPU/RAM/etc. meter with 6x 1mA ammeters and want them to be lightened up with a little LED per meter that only shines a little if the meter is around 0% and then get's brighter and brighter according to the meter.
Is that possible with the 6 PWM outputs from the Arduino? How do I have to solder that together?
Since mechanical galvonometers (that's the precise word for the analog ammeters you mean) have a mechanical mass they automatically low-pass-filter a PWM signal nicely. You just need to limit current appropriately. For a 1mA FSD (full scale deflection) you want a total of 5k resistance from a 5V PWM signal. The meter itself will have a resistance of a few hundred ohms or so (this should be in the specs), so try a 4k7 resistor in series.
Yup, perfect - make sure the resistor for the LED limits the current to 10mA or less or the output voltage to the meter will droop (or use a different pin and drive the LED upto 25mA. The pin output transistors have a finite resistance around 30 to 40 ohms when running from 5V