Why does the gyro need the ADC?

[Matt Krass]

Originally Posted by KenWittlief

the full scale output of the gyro matches the full scale input range of the ADC: 0 to 5V.

Darlingtons have very high gain. Depending on where you centered the bias you would greatly expand a small portion of the gyros output, and cause the rest of its signal to be over or under the range of the ADC.

If you want a more sensitive gyro there are different versions available.

Two of the more common ones used are the Analog devices 150 and 300 degree/second models. The 150 has a smaller range of measurable rotational velocity, but twice the resolution. Since 150/2.5 = 60 degree/second per 0.1 volts whereas the 300 degree/second model has a greater operating range, but half resolution of the 150 since 300/2.5 = 120 degrees/second per 0.1 volts.

I used 2.5 because half of the range is one direction (above 2.5v) and the lower half is the opposite direction (below 2.5v)