How much current can the Uno supply on the 5 volt pin, I can't find this info in the specs.
I'm wondering if it enough to run my motor circuit (SparkFun's 1:100 Mini gearmotor @ 90 mA). I'm using the H bridge as decribed here: http://itp.nyu.edu/physcomp/Labs/DCMotorControl
It'll just be used for about 2 seconds at any one time. It does have a high stall current, though my setup will not be able to stall the high torque gear ratio.
There was just a thread on this yesterday:
You can probably get away with only 90mA, but I still don't like connecting motors directly to the 5V node on the Arduino. Motors are noisy and spikes can damage the Arduino. Best to power the motor driver off whatever power source you're using for the Arduino itself.
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The Arduino Drum Machine: 14-track MIDI drum machine sequencer / groove-box
Thanks! I think I will remove the DC Jack from the board, and put a DC Jack on my shield. Then I won't have to send any current through the Uno. I'll use a 7805 regulator for my motor. It will be powered from a 12 volt 1 amp wall wart. They run about 16 volts with no load, that should be fine to feed directly from the DC Jack on my shield into the Vin PIN on the Uno to power it, right?
The input voltage for the Uno is recommended as 7V-12V, 20V maximum so 16V is "ok" but lower is better. How about a 9V wall wart?
Why do you need a 7805 regulator for your motor? Why not just run it at 12V (or 9V) and use PWM to control the effective voltage/power?
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The Aussie Shield: breakout all 28 pins to quick-connect terminals
I need 12 v to run something else- a solenoid.
I'll just through a 7812 on my shield as well to power the Uno Vin pin. With my solenoid and motor power coming directly off my shield, my Uno won't really be drawing a whole lot of current, I don't think, just telling things when to turn on/off, and powering an LCD.
I don't need any control over my motor speed, just forward/reverse, and I don't have any extra pins to regulate it's voltage.
I dunno, this 7812 gets really hot when my solenoid turns on. It's dropping the voltage from a 12 volt wall wart down to 12 volts, so I didn't think I'd even need a heat sink. The solenoid is 550 mA. I think I'll just use a 9 volt wall wart. (the solenoid turns on if I hook it up to a 9 volt battery). And a 9 volt wall wart will probably end up being closer to 12 volt any way. then I also won't have to worry about the 12 volt wart putting 16 volts into my Uno, when the solenoid is not running.
SouthernAtHeart:
How much current can the Uno supply on the 5 volt pin,(SparkFun's 1:100 Mini gearmotor @ 90 mA).
Arduino has 40mA on it's pin's so going on with as other's have defined in here for a external power supply is the thing.
Nishant:
SouthernAtHeart:
How much current can the Uno supply on the 5 volt pin,(SparkFun's 1:100 Mini gearmotor @ 90 mA).Arduino has 40mA on it's pin's so going on with as other's have defined in here for a external power supply is the thing.
Note that the arduino +5vdc power pin on the sheild connector is not the same as any of the digital output pin's current limit. They have different current limits.
Lefty
That's what i meant!