I might be missing something fundamental, so bear with me…
I have a motor that takes 3V. I wanted to control it (simple on/off) from the Spark Core.
However, when connecting it to any digital or analog pin it didn’t quite have enough to spin (I can get it going with my fingers). Hooking directly up to 3.3V/GND works fine though.
Used a multimeter and the pins are only outputting around 2.6V when set to HIGH. Nothing else is connected.
From what I understood, when set to HIGH I expected the pins to output much closer to the 3.3V. The core must have enough power as the 3.3V pin is outputting enough.
I can fix my motor woes with a transistor, but I was wondering if this 2.6V maximum from the pins is to be expected?
No, they should (and do with my Cores) output 3.3V (or just short of that), but if you attach a too high load, you might strain the GPIOs.
I guess your problem is not acutally the voltage but the current you’ll demand of that pin (max. 20mA to be safe).
To drive your motor, you should use the transistor you suggested.
But to confirm your low HIGH readings, could you also measure the voltage on a 3V3 pin and a GPIO pin that never had your motor attached (a definetly unfried pin ;-)).
How are you powering your Core? Un- or poorly filtered DC supplies might give you lower RMS voltage than you’d expect from the printed ratings - and this is what you’d measure with your MM.
If you’ve got an oszilloscope, have a look at the qualitiy of your power supply.
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