@davidcoton I have found the specification for the Songle relay. It has a built-in optocoupler: 5V Four 4 Channel Relay Module With optocoupler For PIC AVR DSP ARM and Arduino. Specification : 5V Relay Module 4-Channel This is a 5V 4-Channel Relay interface board. Be able to control various applianc...

@QMESAR Thank you! I have only tried the I2C protocol and didn’t even think about trying SPI. In the BME280 specification is states that only (I2C) 2 addresses are available. That is why I was concerned if RPi could handle 3 sensors. Next step is to google SPI :) @davidcoton Thank you for all your i...

Hi everyone I have an idea for a Raspberry Pi project: I want to control ventilation in 3 rooms in my house based on the humidity. The BME280 sensor is able to read the humidity and the Songle relay should be able to control when the ventilation must be active. My first concern: is it even possible ...