Published Paper Details:

The project proposes a solar-powered cell phone charging system that operates on a coin-based payment method. With the widespread use of mobile phones for personal and business communication, providing a public charging service has become a necessity. While some people argue that this may not be a profitable business since most individuals can charge their phones at home, office, or in their vehicles, it remains essential for individuals who forget their charger or are on the go. This is especially true for students, commuters, and people attending conferences. The charging system can be installed in various locations such as hotels, conference centers, leisure centers, shopping malls, internet cafes, colleges, airports, train terminals, etc., to cater to the needs of mobile phone users who require a quick recharge for a nominal fee of one rupee. The system is designed using a Raspberry Pi, which facilitates the countdown timings for a specified period while displaying the remaining time on an LCD screen. The system is equipped with a detector sensor and an LDR (Light Dependent Resistor) that enables solar tracking. This solar tracking system helps to optimize the charging efficiency of the system by continuously adjusting the solar panel to face the direction of maximum sunlight. Additionally, a relay output is latched during the timing period, indicating that the charging process is in progress.