Reading data from digital pressure sensor (Pressure sensor SPD100GD)
From the data sheet, a single byte on the wire would look like this:



I do not believe your UART could decode this, so you may need to resort to bit banging a digital IO pin.

Start at the left; a stop bit is a high for an entire bit period. Wait for a transition to low and measure the time until transition to high. Wait for a transition to low and measure this time. 

If those times are equal, this is a start bit. These two measurements added are a bit period.

Now wait for a transition to high - if this time is 75% of a complete bit time and the next transition to low is 25% of a bit time, this is a '0'.

Rinse and repeat - the unit sends 8 bits of data at a time, with the line held high for a complete bit time to indicate a stop bit.