This is a Crowtail base shield for Raspberry Pi with UART/I2C/Analog/Digital interface. All the Crowtail modules can be plugged onto Raspberry Pi through this base shield. Moreover, this shield has an on-board ADC chip so that analog output modules can be used on Raspberry Pi. The ADC chip used is MCP3008. It talks to Raspberry Pi using SPI interface.
Base Shield for Raspberry Pi With ADC chip MCP3008Development Tools, Raspberry Pi
C-1 , R-2 , I-1