Thanks Ray for the pointer!
I got it working - nice. The PWM pin can be used as input too. I would have looked at the TX pin for serial communication.
Is this 2-way communication on a PWM pin common? When I read the data sheet for the sensor there is:
"When MCU sends a start signal, DHT11 changes from the low-power-consumption mode to the
running-mode, waiting for MCU completing the start signal. Once it is completed, DHT11 sends a
response signal of 40-bit data that include the relative humidity and temperature information to
MCU. Users can choose to collect (read) some data. Without the start signal from MCU, DHT11
will not give the response signal to MCU."
Why would the PWM pin be better than the TX pin for serial communication?