Asked — Edited
Resolved Resolved by Rich!

Possible Dumb Question On Ezb 4 I/O Pin Power Limit

Ok, so I have yet to use an EZB controller, so this may be a seriously dumb question.... I did a quick search (read quick... LOL), but didn't find my answer... Typically the micro controllers I am used to in the past (Basic Stamp, AtomPrp) can supply about 20mA per pin... Can I assume the EZB4 is the same? If not, what is the power supply limit of the EZB4 pins?


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I would assume so, although if you need more it is recommended to use the TIP Transistor Circuit to use the +5v of the port rather than the Signal, which will give substantially more power.


At rryerson , take in mind the digital signal pin and power pins are not the same.


@jstarne1..... Yeah, sorry my bad... I meant the power pin. Just was wondering how much power the each of the power pins can supply....



The ezb v3 had a 5amp regulator. We had a lot of trouble with them because they didn't have enough power to supply more than a few servos. So we researched and found new heavy duty metal geared servos that are 7.4v tolerant. The decision was to provide the input voltage to all digital pins except the analog pins. So what ever power you supply to the ezb comes out of the power pins. We recommend 7.4 volts if you're driving our servos. Otherwise, we will have a power module available very soon. Jeremie had the test pcbs printed today and once they are verified, they'll be on the site.

The power modules have a voltage regulator to power 5 volt items, such as sensors.


Thanks DJ, That makes sense... I guess I should have started off by asking can a sensor that draws more than 20 mA (such as a super bright 5V LED drawing about 140 ma) be plugged directly into the board's 3 pin digital ports (to control it) or will I need a switching 5V relay (or mosfet)?


We have a switching transistor module also, which can be used for a super bright led. No microcontroller will be able to (by spec) power high current devices. You may get away with it - but we don't suggest it:)


Here is the standard diagram for tip120 use. Just remember it's designed to open or close the ground connection of your higher current item. Darlington switching transistors are 1amp current capable. User-inserted image


Thanks guys.... it was a question of wishful thinking and/or laziness on my part... I'll go the direction Rich and Jstarne1 suggested....