Hi,
I’m interested in purchasing one of these Dual MC33926 motor drivers.
I was reading about the option of powering the Arduino and motor shield from the same battery source in the User’s Guide. It looks like I would use the 0.1″ shorting block on the power jumper. Now if I want to also stack a Sensor shield on top e.g. with a accelerometer/ gyro MPU6050, do I have to do anything different? Any considerations I should heed?
Last question is, with the shorting block in place, I know one should then not use the Arduino power. But is it safe to connect via USB to a PC while battery connected?
If your sensor board draws power from the VIN pin and you have the jumper connected on the MC33926 shield, you should make sure that the voltage of your power supply is within the specifications of your sensor shield. However, if the shield gets power from either the 5V or 3.3V pin, no special considerations are needed. Please note, when stacking multiple shields, you should make sure there are no conflicts between the pins they use. You can find a full list of pins the MC33926 shield uses in the “Shield Connections: Signals, Power, and Motors” section of the dual MC33926 motor driver shield user’s guide.
As for connecting your Arduino to a PC through USB while having the shorting block connected, (assuming you are supplying the shield with an appropriate voltage) it is the same as powering the Arduino through its DC power jack while USB is connected. Arduino intends for this to work, but we generally do not recommend doing so for the reasons mentioned in this thread.
There is not a regulator on the MC33926 shield. When the jumper is in place, VIN on the Arduino will be connected to the motor power supply. The 5V regulator on your Arduino will then convert the voltage to supply the 5V pin, which can be used by the sensor shield. Please note, the current draw of all your sensors should not exceed what the 5V regulator on the Arduino can deliver.
Ah that’s good clarification, I think my sensors work with 5v.
To finally get the regulated 5V from the Arduino to the sensor shield, would a way then be to cut / bend the sensor shield’s VIN pin, and then stack on top of the motor shield as the third layer?
From the sensor board’s product page, it does not look like VIN is connected to anything on the shield, so you probably do not need to do anything special to the VIN pin when stacking the shield onto the motor driver shield.
