This is an emulation of the DHT11 type temperature and humidity sensors
based off the data sheet.

I've got two devices that claim to be DHT11 off online retailers, and the
PIC code seems to work on real hardware with both of them, however one of
them needs a delay between reads to be stable while the other doesn't. 
My suspicion (since the cases and labelling are quite different) is that
one or both isn't really an original DHT11 but a clone.

The PIC code started off as the usart_test.asm code
