There are four ways to supply power to your Arduino projects. Do you know them all?
So here is the situation. You are done programming and testing your Arduino project prototype and are now ready to take the project out of the breadboard and install it into your intended location. But how will you provide the power to the board once it is detached from the computer?
There are actually four ways to provide power to the Arduino. We will discuss each one starting from the obvious and simple to the more complicated ones.
1. The USB Port
You may use the USB-B port of the Arduino Uno board to supply power to it. You may connect it to an old mobile phone charger or a portable power supply. Using this method, you can be quite sure that the supply is properly regulated since USB ports and power supplies are made to provide a steady supply of 5V as their outputs.
2. DC Power Jack
The DC power jack on the Arduino Uno board is designed to accept a DC input voltage of up 20 volts. However, the recommended supply voltage is from 7 to 12 volts to protect the voltage regulator components from overheating. You may use power adapters that can be plugged into a wall power or 9V batteries using a suitable battery clip with a DC power jack adapter.
3. Onboard Vin or Voltage Input Pin
The Vin pin is connected to the Arduino Uno board in the same way as the DC power jack. This method however is a little bit more complicated since there will now be two points of connection instead of a single one. In terms of the input voltage, the Vin pin can take up to 20 volts just like the DC Power jack.
One word of caution though, make sure not to interchange the ground and positive pins since the Vin pin has no reverse voltage protection. A mistake at this method may permanently damage your board.
4. The 5V Pin
This might surprise you but the 5V pin can be also be used either as an input power supply port for the Arduino board. However, there are some precautions to be strictly observed, otherwise your board might get damaged.
First, you must be sure that there is no other power supply connected to the board. This means nothing must be connected through the USB Port, the DC power jack and the Vin pin.
Second, your power source must be properly regulated. The input voltage here must not exceed 5.5V since this port bypasses the onboard regulator circuit. Making a mistake here may permanently damage your Arduino board.