Voltage at output pin of a controller
Well, you're not disclosing the part number of the chip nor the exact schematic, so it's pretty hard to guess, but I'll try. 

Take a typical PIC18F part, the PIC18F1220. When operating from a 3V supply, the \$V_{OH}\$ of a port pin looks like this: 



You are observing a drop of about 1.07V from Vdd. From the graph, that would typically represent a current draw of about 8mA. So I might guess that you've got about a 200-300 ohm load (to Vss) on the port pin, which is quite a heavy load. 

Edit: Given the actual data sheet for the PIC18F in question, a curve similar to the above is not provided, however there is a relevant line in the specifications: 

The PIC is guaranteed to provide at least 2.4V provided you draw less than 6mA over the -40~85°C temperature range. Which leads us to the conclusion that the load exceeds 6mA by some margin (since it's probably not 85°C and since 2.23V &lt; 2.4V), as previously concluded.