Analog to Digital Converter for Raspberry Pi: MCP3008

This Analog to Digital Converter takes in up to 8 analog inputs and outputs them digitally using the SPI protocol(this means it requires only 4 digital pins on your microcontroller to read all 8 analog inputs). Just hook up this Analog to Digital Converter to your Digital Microcontrollers such as the Raspberry Pi, and you will have 8 analog inputs with 10-bit accuracy!

Quick Getting Started Pin Hookup Explained:

• 8 Analog Input Pins:

• Pin 1: Analog Input 1 (CH0)
• This is the pin you will connect your analog input signal to(for example, your analog sensor output).
• Pin 2: Analog Input 2 (CH1)
• This is the pin you will connect to your second analog input signal. 
• Pin 3: Analog Input 3 (CH2)
• This is the pin you will connect to your third analog input signal.
• Pin 4: Analog Input 4 (CH3)
• This is the pin you will connect to your fourth analog input signal.
• Pin 5: Analog Input 5 (CH4)
• This is the pin you will connect to your fifth analog input signal.
• Pin 6: Analog Input 6 (CH5)
• This is the pin you will connect to your sixth analog input signal.
• Pin 7: Analog Input 7 (CH6)
• This is the pin you will connect to your seventh analog input signal.
• Pin 8: Analog Input 8 (CH7)
• This is the pin you will connect to your eighth analog input signal.

• 1 Output Pin:

• Pin 10: Output (Dout)
• This pin is the digital output of the 8 analog input pins. Data is sent out using the SPI protocol. Connect this to your Raspberry Pi or other microcontroller..

• Power Pins:

• Pin 16: Power (VDD)
• This pin provides power to the chip. Give it 2.7V - 5.5V
• Pin 9: Ground (DGND)
• This pin is the Ground for the chip. Give it 0V
• Pin 15: Analog Voltage Reference (VREF)
• This pin tells the chip what the maximum analog input voltage is. Connect it to your analog input device's power (such as your sensor's power pin) This voltage should be a value between 2.7V - 5.5V (3.3V if you're powering your sensor off the Raspberry Pi)
• Pin 12: Analog Ground (AGND)
• This pin tells the chip was the lowest analog input voltage is. Connect it to your analog input device's ground (such as your sensor's ground pin). This voltage should be 0V for all standard purposes.

• Other Pins:

• Pin 13: Clock (CLK)
• This pin is pulsed high and low by your microcontroller. Every time this pin is set low and then high, one bit of data will be transferred to your microcontroller on Pin 10 (DOUT). (Connect this pin to your Raspberry Pi or other microcontroller. The SPI protocol will use it.)
• Pin 11: Data In (DIN)
• This pin is where data is sent in to the chip from your microcontroller. (Connect this pin to your Raspberry Pi or other microcontroller. The SPI protocol will use it.)
• Pin 10: Chip Select (CS/SHDN)
• When this pin is low (0V) it means this chip is active. This pin is used when you have many SPI devices hooked up to the same SPI pins on your microcontroller and would like the ability to talk to one device at a time. If you are not hooking up more than one SPI device to your microcontroller, leave this connected to GND (0V). Otherwise, connect this pin to your Raspberry Pi or other microcontroller. The SPI protocol will use it to select which SPI device it is talking to.

Specifications:

• Operating Voltage: 2.7V - 5.5V
• Max Sampling Rate: 75 ksps @ 2.7V; 200 ksps @ 5V
• Number of Pins: 16
• Operating Temperature Range: -40 to 85 C
• Analog Input Resolution: 10-Bit
• Output Protocol: SPI Serial (Digital)
• Manufacturer Part Number: MCP3008

Click here to download the Datasheet.