lamaPLC: RP2040_ETH_Modul: Read BME 680/688 sensor data

The program reads the following data from the BME680 sensor and displays it in the Modbus input registers:

• Temperature: Provides ambient temperature readings.
• Humidity: Measures relative humidity.
• Barometric Pressure: Can be used to calculate altitude or track weather changes.
• Gas (VOC): Features a heated metal-oxide sensor that detects Volatile Organic Compounds (VOCs) to estimate indoor air quality.

The program is also suitable for reading the BME688 sensor.

import machine
from machine import Pin, I2C
import time
from bme680 import BME680_I2C  # Import the driver you saved earlier
 
# I2C configuration for RP2040-ETH
# Using I2C port 0, SDA on Pin 4, SCL on Pin 5, at 100kHz
i2c = I2C(0, sda=Pin(4), scl=Pin(5), freq=100000)
 
# Initialize the sensor
# The default I2C address is usually 0x77 or 0x76
try:
    bme = BME680_I2C(i2c, address=0x77)
    print("BME688 initialized successfully.")
except Exception as e:
    print("Could not find BME688. Check wiring or address (0x76/0x77).")
    # Try 0x76 if 0x77 fails
    bme = BME680_I2C(i2c, address=0x76)
 
def display_data():
    print("\n--- BME688 Environment Data ---")
    # Read and print data to Serial Monitor
    print("Temperature: {:.2f} °C".format(bme.temperature))
    print("Humidity:    {:.2f} %".format(bme.humidity))
    print("Pressure:    {:.2f} hPa".format(bme.pressure))
    print("Gas Res.:    {:.2f} Ohms".format(bme.gas))
    print("-------------------------------")
 
# Main loop
while True:
    try:
        display_data()
    except Exception as e:
        print(f"Error reading sensor: {e}")
 
    time.sleep(2) # Wait 2 seconds between readings

Output example

--- BME688 Environment Data ---
Temperature: 22.03 °C
Humidity:    33.84 %
Pressure:    978.13 hPa
Gas Res.:    12946861.00 Ohms

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