Introduction

Raspberry Pi supports both I2C and SPI protocols, but combining them in a single project often confuses developers. In this guide, we introduce the Hybrid-Bus Control Method, which allows you to use I2C and SPI devices together in Python without conflicts.

Hardware Setup

• Raspberry Pi (any model)
• 1 I2C device (e.g., BMP280 sensor)
• 1 SPI device (e.g., MCP3008 ADC)
• Breadboard + jumper wires

Connections:

• I2C: SDA (GPIO2), SCL (GPIO3)
• SPI: MISO, MOSI, SCLK, CE0
• Ground and 3.3V shared

Enable Interfaces

sudo raspi-config
# Enable I2C and SPI under Interface Options
sudo reboot

Python Code (Hybrid-Bus Control Method)

import smbus2
import spidev
import time

# I2C Setup (BMP280 example)
i2c = smbus2.SMBus(1)
BMP280_ADDR = 0x76

# SPI Setup (MCP3008 example)
spi = spidev.SpiDev()
spi.open(0, 0)
spi.max_speed_hz = 1000000

def read_i2c_temp():
    # Example: read chip id register
    chip_id = i2c.read_byte_data(BMP280_ADDR, 0xD0)
    return chip_id

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

try:
    while True:
        temp_sensor = read_i2c_temp()
        adc_value = read_spi_channel(0)
        print(f"I2C Temp Sensor ID: {temp_sensor}, SPI ADC Value: {adc_value}")
        time.sleep(1)
except KeyboardInterrupt:
    pass
finally:
    spi.close()
    i2c.close()

Why Use the Hybrid-Bus Control Method?

• Works with both I2C and SPI devices on the same Pi
• Avoids bus conflicts by separating function calls
• Scales for multiple sensors (mix of I2C + SPI)
• Fully Python-compatible

Conclusion

With the Hybrid-Bus Control Method, you can easily run both I2C and SPI devices in Python on your Raspberry Pi. This approach is lightweight, flexible, and requires no extra hardware.