I have an Arduino Nano and a mega but I can't use my Arduino mega power adapter to nano. There's no port to connect it. But the pin diagram says I can use pin 30. But how do I connect the Ground pin? Do I need a resistor to connect the 5V input? Please somebody help me to solve this.
From the Arduino Nano webpage:
Power:
The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.
There is a VIN Pin and there is a Ground Pin.
The instructions do not say anything about a resistor.
Where did you get that idea from?
I use the pin 30 and 29 with a AC/DC 9V power adapter to read 2 NTC 10K sensors and the readings from this sensors were not very correct but until now I don't found why... connected in the usb port of computer work perfect other form don't