Sensors and actuators on Raspberry Pi

Brief description, encountered problems and working solutions only.

Sensors:

• Water flow sensor YF-201S.

• This is hall-effect sensor. About 450 pulses per liter. There are 1/2" and 3/4" thread versions.

• Wind speed sensor (anemometer).
• Button.
• Distant IR temperature sensor MLX90614 (and similar MLX90615, MLX90614).

• This is pretty tricky distant temperature sensor. The tricks are:
  1. The sensor has very special I2C treatment of stopbits. Solution.
  2. The Object 2 temperature is impossible to get. At least, I can't get it :) Please, share your knowledge.

• Barometric pressure, temperature, relative humidity sensor [BME280].(https://github.com/igrowing/RaspberryPi/blob/master/sensors/bme280.py)
• Luminosity/light sensor MAX44009.

• This is not that popular light sensor. It has no additional functions except luminosity measure. It measures the light up to 180K Lux: widest range I found for that sensor size.

• Light, color, proximity and gesture sensor APDS-9960.

• Buttons are not cool, old fashioned. Let's control the device touchlessly! :)

• AC current sensing with ADS1115.

Actuators:

• OLED screen 0.96" over I2c (IIC) interface SSD1306
• Relays and AC water valves
• Latching relays and DC water valves with L9110
• Latching relays and DC water valves over I2C with DRV8830