Using 5DOF unit reference output.

Development Boards MicroMod
1

I have an 5DOF unit from sparkfun.

This unit containg IDG300 gyro. Gyro has a 1.23V reference output.

According to datasheet (http://www.sparkfun.com/datasheets/Comp … asheet.pdf) this output can be used as a reference of my microcontroller ADC (I use LPC2138 with 3.3V).

But as I know, gyro rate output can be from 0…3.3V, not 0…1.23V.

How should I use gyro reference output to measure full rate range?

Thanks.

2

It’s not really worth the effort.

But, two ways to do it are:

  1. Use voltage dividers to bring the gyro (and optionally accelerometer) outputs down to below 1.23V

  2. Use an op-amp to multiply the 1.23V reference to, say, 2.46V (the gyro maximum output is actually close to 2.5V, not 3.3V)

3

Thanks, i think op-amp is a good solution.

It’s a pity that LPC2138 does not have embedded op-amp. =(

Which op-amp I should use? Should it be precise, or LM358 is enough?