Adding an MCP23017 16 port IO expander to Arduino or Esp8266 or Attiny85 or…….. – Arduino, ESP8266, ESP32 & Raspberry Pi stuff
Control 65,280 Relays with Arduino | Use the IO Expander and Relay Expander to control up to 65,280 relays with your Arduino: https://bit.ly/2GxidCV | By Hackster.io - Facebook
5x Relais Expander | eBay
Control Up to 65,280 Relays with Your Arduino! - Hackster.io
Haljia 6 pieces 1 channel relay board relay module with optocoupler insulation support high and low level trigger universal high profermance 1 channel relay expansion board for Arduino 5V : Amazon.de: DIY & Tools
5v 2 Channel Relay Module Low Level Triggered 2-way 2ch Relay Module With Optocoupler Expansion For Arduino Arm Pic Avr Dsp - Relays - AliExpress
5V One Channel Relay Module Low Level Trigger For SCM Household Appliance Control Relay Expansion Board For Arduino: Buy Online at Best Prices in SriLanka | Daraz.lk
Control Up To 65,280 Relays With Your Raspberry Pi! - Hackster.io
Control Up to 65,280 Relays with Your Arduino! - Hackster.io
SUNFOUNDER 2-Channel DC 5V Relay Module with Optocoupler Low Level Trigger Expansion Board Compatible with Arduino R3 MEGA 1280 DSP ARM PIC AVR STM32 Raspberry Pi: Amazon.de: Spielzeug