[mkanoap]

I tried it tonight and it worked!

At first I connected them via my multi-meter, and while the light on the pi flashed, it never came up on my wireless network.  I observed it pulling between 110 and 170 mA during this time, but the lights on the wireless dongle never came on.

I had decided that there just wasn’t enough current, but took the multi-meter out of the circuit and tried again before giving up.  That time (and every other time I have tested) it worked, the pi booted up and joined the network.  I’m not sure why my multimeter would keep it from working, maybe I’m not using it right.

Anyway, I’m happy to report that a raspberry eggbot can run with a single power cord.

[mkanoap]

Thanks for the quick, detailed, and helpful response!

I was being pessimistic about the power requirement based on my last pi project which I ended up having to buy a powered USB hub and moving peripherals to it.  But that was with a camera and two wifi dongles plus the occasional USB keyboard.  So, as you suggest, I should just measure the actual amperage of the device with the single wifi dongle I’ll be using. 

I have two servos because I’m using the engraver attachment. I know it’s not really a servo, but I was making the (possibly poor) assumption that it had similar characteristics because it plugs into a servo port and is driven from the same rail.   I’m not planning to drive the servos from anything other than the EBB, I was just figuring the highest total load on that voltage regulator would be whatever the PI pulls plus the peak current from the engraver motor and pen lifting servo.

I guess I should measure the eggbot too and then just add together the two numbers I get.

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