Can Raspberry Pi Read Analog Sensors?
No, the standard Raspberry Pi does not have a built-in ADC (Analog-to-Digital Converter), so it cannot directly read analog sensor signals (e.g., from potentiometers, thermistors, or analog temperature sensors like LM35).

Why?
Raspberry Pi’s GPIO pins are digital-only—they can read just HIGH (1) or LOW (0) voltage levels. Analog signals, which vary continuously (e.g., 0–3.3V), need to be converted to digital values using an external ADC.

How to Read Analog Sensors on Raspberry Pi
You need an external ADC chip or module connected via SPI or I2C. Popular options:

Example Setup: MCP3008 + Raspberry Pi

1. Connect MCP3008 via SPI (MISO, MOSI, CLK, CE).
2. Connect analog sensor to one of MCP3008’s channels.
3. Use a Python library like spidev to read values:

python

import spidev

spi = spidev.SpiDev()
spi.open(0, 0)  # Bus 0, Device 0 (CE0)

def read_adc(channel):
    adc = spi.xfer2([1, (8 + channel) << 4, 0])
    value = ((adc[1] & 3) << 8) + adc[2]
    return value

print("Analog value:", read_adc(0))

Summary