I'm developing my first Arduino's project and I'm experiencing a weird problem.
The configuration is quite simple:
- an Arduino Nano connected to a breadboard
- a simple circuit with LED and Resistor (330 Ohms) in serie connected to a digital pin
- a digital voltmeter connected to 5V pin
Both LED and Voltmeter share the same ground. When I switch on/off the LED intermittently, the voltmeter value is moving around 5V.
I would like the voltmeter to be perfectly stable at 5V irrespective of the LED since they are supposed to be independant. I suspect a shared ground issue. Could someone help me?
To give you more precisions, the voltmeter is stable at 5V when the LED is not connected. I have presented a simplified version of the problem. For instance, if I use several RGB LEDs in parallel, the voltmeter shows values from 4.5V (when LED is white) to 5V (when LED is off).
Thank you for you help,