according to the K22 datasheet (page 6 & 5) u dont need ur own pull-up resistor (4.7k to 5V), because the K22 already contains its own on-board...
the 10k is just for the case, that u re-conf pin #14 as output pin and give 5V on it... 
everything clearly above 125 Ohm should be safe here, because arduino pins can take 40mA...
according to the K22 datasheet there is already a 120 Ohm resistor on the K22 board...
the BC847 on the K22 can take even more than 40mA...
i like my approach (without pulseIn()) still better...
-arne