Quote Originally Posted by T.Jackson View Post
Seems a bit of a waste to have one LM334 for each range though.
Hi Trent,

The price of a LM334 is USD 1.20.

If you have just one LM334 you will have to switch the resistors and this
will reduce the accuracy of the measurement system. Just supply the +5V
to each LM334 with an I/O of the microcontroller and you are done. The
transistor BC547 is not needed because the I/O of a PIC can supply more
than 10mA.

Best regards,

Luciano