Help with my writing tablet

[chatfouz]

i have a writing tablet and i am studying chinese. It is great for writing and practicing chinese characters. However for the past 2 weeks i have been trying to figure out how to use it to write Pinyin. āáǎàēéěè. I can only input these characters using a clumsy keyboard and is very difficult to have to switch from the writing tablet to move to a keyboard then back. Please if someone can tell me how to input pinyin with this writing tablet.