I'm new to IoT. I'm trying to connect more than one device to relay and control via ESP board(tested with esp8266 and esp32), I'm using mqtt connecton for signaling.

So here's whats happening

  1. If I connect just 1 relay pin to the esp8266 board, it works fine and I ested for 3-4 days already.

  2. If I connect other pins(2+ channel relay) of the relay to the esp8266 board, I can see it working for 4-5 minutes and after that, it starts fluctuating(relay led gets dim and you hear click sound) and MQTT responses are not received.

  3. This is only happening when I'm connecting to external power source of 5V. When I connect via USB from my laptop, it works fine.

Note :- I tested it on esp32 board as well, with a different relay, it's showing the same behaviour.

So, I'm wondering if it is because of some power fault, do I need to power relay and board with individual 5v?

  • 2
    point #3 indicates that the problem may be the external power source ... it is unable to provide enough current to energize more that one relay reliably ... please draw a wiring diagram that shows how everything is connected ... also, which relay board are you using?
    – jsotola
    Sep 8, 2020 at 4:20
  • Have you taken a meter and measured the input and gpio output voltages?
    – hardillb
    Sep 8, 2020 at 7:14
  • @hardillb, yes, i did, its giving 5 volts. One important point is, its not happening instantly, it happens only after 5-10 mins and it works fine till then. Sep 8, 2020 at 11:50
  • @hardlib, i checked the output power again, i'm seeing a constant 3V. I'm hoping this is the problem. What do you guys suggest for powering esp32? I just saw a youtube video and i made it using 7805 voltage regulator and two 470 microfarad capacitor at input and output of the Voltage Regulator. Sep 8, 2020 at 12:22
  • That's a question for electronics.stackexchange.com
    – hardillb
    Sep 8, 2020 at 13:38


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