Pololu Dual VNH5019 Motor Driver Shield and 3.3V Logic Power

The specs for the Dual VNH5019 motor driver shield say that it is compatible with 3.3V systems, but I notice that the 3.3V pin on the Arduino interface is not used. I would like to use this with the Arduino DUE, a 3.3V board. The DUE still has a 5V output that will connect with the logic supply of the shield and power it, so how can I be sure that the 5V supply will not find its way to the input pins of the DUE through the logic connections?


The only pins that return data to the controlling Arduino from the VNH5019 shield are the current sense pins. If those current sense pins measure a large enough current (upwards of ~23A), there is a chance that the voltage generated could damage the inputs on the Due. The Due’s processor’s internal protections should generally be able to protect it from those high voltages generated, but if you want to be safe, you could read our recommendation on how to protect those pins in a note (“Note for Due users”) under the “What You Will Need” section of the user’s guide, which can be found under the “Resources” tab of the shield’s product page.