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Nucleo - Power

VIN from EX8874

  • EX-MotorShield8874 provides VIN output, which can be used to power the Nucleo 64/144.

  • In order to take advantage of the EX-MotorShield8874’s single power source capability, you will need to move the Nucleo power source jumper.

  • On the Nucleo-64s it’s jumper JP5 which you move from the U5V position (pins 1+2 jumpered, USB 5V source being used) to the E5V position (pins 2+3 jumpered).

  • On the Nucleo-144s it’s jumper JP3 which you move from the U5V position (centre pins 3+4 jumpered, USB 5V source being used) to the VIN-5V position (rightmost pins 5+6 jumpered).

  • In both cases this will power your Nucleo using the EX-MotorShield8874’s onboard switch mode power supply of 7.2V to the VIN pin, and allows some 800mA of 5V power to be available for the Nucleo and peripherals.

  • Note for programming: Once you do this it will mean you need both the EX-MotorShield8874 barrel jack to be powered AND the USB cable to enable programming. Or you can temporarily move JP5 back to U5V whilst uploading EX‑CommandStation.

  • Power connection sequence: The correct sequence is power on the EX-MotorShield8874 barrel jack, then attach the USB cable according to the STMicroelectronics documentation.

        EX8874 Nucleo-144 pins

VIN voltage

  • Optimum VIN voltage is 7 volts.
    VIN range is from 7 V to 12 V only and input current capability is linked to input voltage:
        800 mA input current when Vin = 7 V
        450 mA input current when 7 V < Vin <= 9 V
        250 mA input current when 9 V < Vin <= 12 V

USB

  • USB can be used for power, but accessory power will be limited.

  • Caution: If VIN jumpers is not set to use USB - and - USB is connected prior to EX8874 being powered, expect enumeration issues and reduced power.

  • Refer to st.com user manuals
        UM1974 Nucleo-144
        UM1724 Nucleo-64