Reference voltage question.

I am using the Analog brand Gyro Sensor ADXRS300 with an ATmega32. The sensor has a reference voltage output that can be used to take more accurate measurements.
The sensor is 2.5 volts on the output at rest and varies 2.25 volts above or below that when the sensor is turned.
I originally had 5 volts on the Aref and it worked fine, but I would like to use the sensors Vref to provide a more accurate sensor reading from the Gyro. How can I use the 2.5 volt sensor reference to provide a reference for the ADC of the ATmega32.
My guess is that I need to double the sensor reference voltage while still keeping it accurate...but how?
~Mike

I've been trying to work with the values by using math but realise that I still need to have the full 5 volts of range.

MrMikey83 said:

I've been trying to work with the values by using math but realise that I still need to have the full 5 volts of range.

Click to expand...

How about using the 2.5V as reference for your A2D, and dividing the analogue output by two (using two resistors as a potential divider), this will bring it within the reference range.

Worked, thanks Nigel

Sorry this is old, but I thought I'd post an update since I changed the configuration.
Someone else asked me why I was splitting the voltages and even using the VRef at all. He told me to use the 2.5V on a normal adc pin and just use "2.5Ref - GyroOutput" and it will give me 0 at rest because the voltages will be the same.

Seems obvious now. :lol:
~Mike