Nextion HMI Display 3.2 Inch 400x240 with Touchscreen

This is not possible in most cases. Most development boards (including Uno, Mega, NodeMCU, D1 Mini V3, etc.) have a diode between the 5V pin and the USB input that lowers the voltage. If the voltage from the 5V pin is lower than the required minimum of the device (see specifications) then it cannot function properly. In addition, many development boards can only provide little power. This can also cause it to malfunction. Using an insufficient power supply can even damage the device. Therefore, make sure that you use a suitable power supply and that it is connected correctly. It is advised to verify the supply voltage by measuring it.

In most cases, this is caused by insufficient power supply condition. Nextion HMIs require a good quality power supply. When the power supply provides too little current, has too low a voltage and/or generates too much ripple, several problems can arise, such as:

• Flashing
• Blurred screen
• Freeze
• Damage to the HMI

A good quality CE-approved power supply is required that can supply enough current and has the correct voltage. If necessary, measure the voltage directly on the Vcc and GND pins of the HMI.