I have some questions about stepper driver DVR8825. I don’t figure out exactly if the potentiometer act as a linear controller on the current limiter (it should be). I mean, if I put the potentiometer half travel I think to have half of the max current, so 2.2A / 2 = 1.1A. From the spec the driver can run without cooling and heatsink at 1.5A (correct me if I’m wrong), but also if I regulate it 1/3 of the max travel (expecting 0.7A max) the driver works but it became quite hot fast. What is my mistake? I’m using it with wantai motors 42BYGHW811. They develop 4.8kgcm of torque at 2.5A so little bit overpowered respect the driver, but from my knowledge of chopper driver it is the driver to control the real current flowing, so I’m expecting that with this setup I can turn all the potentiometer full to deliver max current (2.2A) with heatsink and fan and have motors running with about 4.2 kgcm, is it my calculation correct? But considering how fast the driver became hot I’m a little bit worried to do this.
Last question, how can I measure the delivered current in real time? Is it sufficient to put my multimeter in series with one phase of the motor?
Thank you all in advance for the support 
Information you’re looking for can be found here: http://www.pololu.com/catalog/product/2133 if you’re using a non-pololu variation, make sure you adjust your calculations for whatever current sense resistor they use.