Quantity   Component name
1 × PC817 Optocoupler (DIP-4 PC817C) <a target="_blank" rel="noopener noreferrer" href="https://www.amazon.com/gp/product/B07TFHZNVP/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&amp;psc=1">https://www.amazon.com/gp/product/B07TFHZNVP/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&amp;psc=1</a>
1 × NodeMCU v1 ESP8266 Development board <a target="_blank" rel="noopener noreferrer" href="https://www.amazon.com/gp/product/B07HF44GBT/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&amp;psc=1">https://www.amazon.com/gp/product/B07HF44GBT/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&amp;psc=1</a>
1 × USB micro cable
1 × 5V 2A power supply