I am trying to convert the signal from digital pin 2 on my Uno to 3.3V. I set up a voltage divider with 3 x 1000 ohm resistors. When connected to ground and 5V the divider circuit generates 3.3V correctly, with a calculated input current of 1.7mA. However I connect it to a digital pin, the digital pin voltage drops from 4.8V to .37V. I thought the digital pins were to support 40mA, I was assuming 40mA at the 5V supply voltage. Is my Uno malfunctioning?