I have a SpeakUp 2 Click Voice Recognition module connected to my Arduino Due. The demanded input voltage of the SpeakUp 2 is 3.3V which is good since the Due digital Pins output is 3.3V. When using my multimeter I get an output of around 1.27V coming in to the SpeakUp 2 but when do a Serial.println() of the pin I get 1. I know that the 1.27V is within range being considered a logic 1 but it barely lights up the SpeakUp 2 "ON" LED. When I connect the SpeakUp2 to the 3.3V Power pin it works perfect but I have multiple peripherals that require 3.3V. As of right now I have multiple peripherals bussed from that 3.3V power pin but I would like to know as a concept why the digital pint as an output is not providing 3.3V even when using a 7-12V power jack.
You don't want to power a peripheral with a digital pin output. :o
Plus be careful with the maximum current you can draw from the board: