The MCP3008 ADC is based on successive approximation ADC architecture with a resolution of 10 bits. The MCP3008 has eight input channels for interfacing the sensors on the pins. If so many channels are not required, we can select a four-channel input ADC chip known as MCP3004. These chips are the best way to interface sensors because they support the SPI slave mode to be interfaced with the GPIO pins of the RasPi models A+, B, and B+ and RasPi 2 model B. This MCP3008 chip should be purchased in a dual-in-line (DIP) package so that we can easily insert it on a breadboard while preparing for the project: