Hi All
Thanks for the quick replies.
I figured there would be some way to do it with a simple amplifier but wasn't sure how. I'll have a look at the op-amp solution.
I want to avoid using a microcontroler in the 'remote control' if possible. I'd like to get away with little more than the XBee and it's internal ADC, the joystick and a few other components. The XBee on the Bot puts out PWM proportional to the ADC input from the joystick which I'll read using the Bot's ATmega chip.
I can't do differential ADC on the XBee but I may be able to get clever with Vref. Will have to think about it a bit more. The ADC on the XBee is 10 bit.
Cheers
Andy