SD540 Motor Controller

[philso]

Originally Posted by techhelpbb

Just to share - I have nothing to do with MindSensors or their team.
I merely like the idea of competition for the pricing of FRC motor controls.
It's easy to go back through my post history to show that I have built other controls in the past and expressed public interest in the matter on this forum.

To be fair I also bought 2 Sparks as well.
This is not a Team 11 thing either.
It's just little old me being curious.
I have my own parts to build FRC robots so I don't have to impact Team 11 or 193 operations to do this.
I also have my own machine tools.

At the moment I am planning on doing the temperature and current measurements with an Arduino based data logger but I have more development boards than I care to discuss so I could do this with something more powerful. I will likely use a Dallas 18B20 for the temperature measurement with it installed in a steel cartridge in direct contact with the ESC heatsink and a either a TI or Maxim chip for the current measurement using a current sense resistor of a value I will disclose. It's likely the current sense resistor will be less than 1mOhm right now. I need to disclose that because it has a slight impact on the motor circuit.

Is it too much to ask if one of the Talon SRX's or Victor SP's to act as a point of reference?

As long as the temperature data is measured at the same output current, the value of the current sense resistor does not matter. The losses in the controller are related to the characteristics of the switch devices used (MOSFETS?), how they are driven by the circuitry in the controller, the switching frequency and the output current. As a user, one would only have control over the output current.