If you want to check the level of charging of a battery, then one can use an Arduino battery tester. It can be an attractive tool to detect the left over the battery and then how to use them judiciously. This project is categorized as a basic Arduino project for beginners and hence can be extended to a proper setup.
The project includes equipment like Arduino Uno, Green, red and yellow LED, Zener diode, resistors, and breadboard. The Arduino Battery Tester Circuit is easy to assemble, where the Zener diode is used to test batteries with a voltage greater than 8 volts. This diode allows current to flow in one direction and it reaches the breakdown voltage, from where voltage goes in the reverse direction. This process helps in protecting those parts that can only handle limited voltage like the Arduino.
Resistor lessens the current that comes from the battery in an amount which is suitable for Arduino as high current damages the Arduino. Three different LEDs are also available on the circuit, which represents the amount of charge left in the battery. Red says dead, while yellow represents half battery and green as full. Resistors are connected to each of the LEDs to avoid burning of LEDs.
The ground pin on the Arduino is wired to the ground rail on the breadboard and on the breadboard LED’s are placed. After placing resistor onto positive end of the LEDS, a wire from the resistor is hooked on the Arduino. Analogue pin 0 is connected to the breadboard along with the resistor and the Zener diode. The loose wire coming from the other end to the diode is connected to the ground rail.
The code is comparatively easy and straight forward. The variables of LED’s are assigned to their relevant pin number and the analogue Value variable stores the value coming out from the analogue input. Finally, ledDelay deals in the time length of LEDS to remain on before switching off.
You can get the complete details on the following website.