Forget About Raspberry Pi! Use Your Old Phone Instead. (Really???)

Even old smartphones have a high resolution touch display combined with cameras, speakers, wireless communication, microphones, and other sensors, along with a rechargeable battery, which would be expensive to buy individually.

The process of disassembling a 12-year-old Samsung Galaxy S2 to explore its internal components and functionality.

Issues encountered with components like buttons, spring metal foils, and flash light LED output, leading to the exploration of alternative solutions.

A solution involving USB Serial adapter boards, providing 8 pins for digital inputs or outputs, and connecting LED anodes to the IO pins of the modules.

Explanation of circuit connection, transistor functionality, resistor requirements, and the process of uploading Gerber files from Kicad for board manufacturing.

Details on the soldering process, additional services provided by PCBWay, and obtaining all project needs from a single source.

Guidance on using Android Studio, cloning repositories, handling source files, implementing logic, and positioning widgets in XML files for app development.

Steps to download, run, and upload the app on a phone, including connecting via USB, enabling developer options, and granting permissions for device access.

Addressing power supply issues, connecting a replaceable battery, avoiding risks during soldering, and managing voltage regulation for the phone's operation.

Connecting and testing the phone, observing LED blinking and slider speed changes based on input pins and positive rail connections.

Encouragement to use the demonstrated project as a template for creating custom apps and seeking input on potential project applications.