It features a 30A relay, optocoupler isolation for enhanced safety, and supports both high and low trigger signals. This module is ideal for projects requiring the control of high-current loads using low-power microcontrollers like Arduino, Raspberry Pi, or other development. Most modules include an optocoupler for isolation, so the relay coil doesn't share ground with your ESP32. Some won't trigger reliably at 3. I recommend the 4n37, which are quite robust. In figure 1 on the left you can see the first circuit I tried, using the following code: name: esp-32-try board: wemos_d1_mini32 - platform: gpio id: try_in pin: number:. The relay is a programmable switch that can be used to control ON/OFF electrical devices. WARNING Safety first! Safety first! Please be careful when working with high voltage.
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