the problem is in your draw statement.
// now display Humidity
u8g.setFont(u8g_font_profont29);
thisHumidity = String(humidity) + "%";
const char* newHumidity = (const char*) thisHumidity.c_str();
u8g.drawStr(15,50, newHumidity);
u8g.setFont(u8g_font_profont12);
u8g.drawStr(65,38, "humidity"); /// this posts the word humidity, not a variable.
"humidity" is the ASCII letters humidity , just the word.
humidity = dht11_humidity ; /// loads an analog input into the variable humidity.
I believe you need to use the print function
ug8.setcursor(65,38); // sets the cursor location
u8g.print(humidity) ; // prints the variable in parentheses.
I am at work, can post the exact code tonite.
it uses the Arduino print command.
if you cannot wait, see the tutorials on youtube by Jullian. I think the code is in tutorial #2.
sorry for no help, but until I can get home and get my code, I am useless.
alternatively, you can try the
ug8. drawStr(65,38,humidity) ;
but you did not say that your attempt at newHumidity worked.......
[edited post to fix grammar and spelling]