I need help from you hardware guys out there.
I’m developing a sprinkler controller for my home based on the Panda II and Tinkerer.
I need to drive 8 relays, one at a time, using digital I/O pins on the Panda.
I would like to use this darlington driver: http://www.sparkfun.com/products/312
with this relay: http://www.sparkfun.com/products/10509
in this circuit: see image and link below
Based on the relay datasheet, I think I can drive it with 6.5 or 7 volts?
What value resistors should I use for R1 and R2?
Any other tips / recommendations?