If I use a 9v power supply for my Uno R3, can I use the 5v pin to run an mg90 servo and an Adafruit class D amplifier simultaneously? I've seen 9v power supplies that supply 1 and 2 amps.
The Arduino 5v pin can only supply 150 mA or something like that.
Don't try to power a servo or a motor or anything with a high current draw from it.
...R
The power supply might be able to supply 2A but the Arduino's regulator which reduces it to 5V definitely cannot.
Steve
Okay, thanks!
Just to add some info to this:
Many, many tutorials DO show the servo powered from the arduino 5v pin.
And this can work if it is a small servo without a load.
Usually, a MG90 servo that is simply moving the servo arm back and forth does not cause problems.
But as soon as you attach something to the servo arm that adds load to the motor, or add a second servo, you are pretty much assured that the regulator will be overloaded and the arduino will shut down (or worse).
It is much better to power servos and motors from a separate power supply. Use a common ground where appropriate.
mbewley59:
If I use a 9v power supply for my Uno R3, can I use the 5v pin to run an mg90 servo and an Adafruit class D amplifier simultaneously? I've seen 9v power supplies that supply 1 and 2 amps.
No, you need a 6V supply for the servo. You'll overload the Arduino's on-board regulator trying to pull
high current, and anyway you should not be putting a noisy servo/motor load on a logic 5V supply, keep
all those spikes and noise away from the sensitive electronics.