# Common ground between a current source and a power supply

I want to design a simple circuitry for testing a bench top current source through a load resistor. I want to use MAX9611, and read data through I2C by a micro-controller. The rough circuit schematic I came up with is this: As you can see, the current source comes to RS- pin and goes through r1 to the ground plane.

My problem is, the current source and the power supply for my micro controller and the current sense chip are two different units. e.g. the VCC comes from a 9V wall adapter but the current I want to sense is through a bench top current source equipment.

I am wondering how can I have a common ground? can I just connect the two grounds together? if not, what should I do? Not to mention that I would like to have a clean ground so no noise affects the ADC inside the maxim chip.

Please let me know if I should provide more details