How much Power does a regular ESP32 Board needs in average working with ESPHome? (without any sensor)

I was using an ESP32 NodeMCU board like this:

It had 3 SW-450 sensors (connected to the 3.3V pin).

To power it, I was using my old Chromecast charger

Power Source MST3K-EU Chromecast:
Input 100 - 240v ~ 0.2A
Output 5.1V === 850mA

It worked really well for weeks but since I needed 5V volts for another project I changed it for an ESP32 with a CH9102X chip that I had.

It work ok for a couple of days but then all of a sudden I would not connect anymore, I even could not flash it again, since I read that CH9102X chips are not that stable, I assumed I did something wrong on the second flash process since I can see the “power light” tuning on, and I see the serial port on my laptop.

So, I left it there for later and changed it to this one that I also had.

After flashing, and connecting the sensors, the board would sometimes boot, and connect (I could see the logs), but after a while the wifi connection would drop (the router said the device itself disconnected). Sometimes it would not boot at all.

Every time I took the device to my laptop and see the logs, it would keep the connection. So I thought that maybe there was a problem with the used pins (32, 34, 35). So I took all the setup to my laptop to maybe change them, and to my surprise, while connected to my laptop, the device will boot and stay online.

So this pointed me that maybe the problem was the power, and I was Right, I change the charger to my Samsungs tablet charger for a test and It worked continuously

Input 100 - 240v ~ 0.3A
Output 5.1V === 1.55mA, 7.8W

So this brings me to the question, How much power does an ESP32 Board need by itself on average? Does 850mA is not enough?

This is my yaml file btw:

  name: vibration-detector
  friendly_name: Vibration Detector

  board: esp32dev
    type: arduino

# Enable logging

# Enable Home Assistant API
    key: "redacted"

  password: "redacted"

  ssid: !secret wifi_ssid
  password: !secret wifi_password
  # power_save_mode: NONE
  reboot_timeout: 10min
  # fast_connect: true

  # Enable fallback hotspot (captive portal) in case wifi connection fails
    ssid: "redacted"
    password: "redacted"


  # Sensors that the ESPhome unit is capable of reporting
  - platform: wifi_signal
    name: "WiFi Signal"
    update_interval: 60s
  - platform: uptime
    name: "Uptime"
    update_interval: 30s

  # Green
  - platform: gpio
    name: "Izquierda (34) Green 🟩"
      number: GPIO34
      mode: INPUT
    device_class: vibration
      - delayed_on: 10ms
      - delayed_off: 3s #3s

  # Red
  - platform: gpio
    name: "Derecha (35) Red 🟥"
      number: GPIO35
      mode: INPUT
    device_class: vibration
      - delayed_on: 10ms
      - delayed_off: 3s #3s

  # Yellow
  - platform: gpio
    name: "Arriba (32) Yellow 🟨"
      number: GPIO32
      mode: INPUT
    device_class: vibration
      - delayed_on: 10ms
      - delayed_off: 3s #3s

I know that each SW-450 needs 15mA to work, which makes it 45mA in total for them.

There is a possibility that the charger is faulty, but that would not explain why it worked without problems with the first board.

Just for fun, because I do not understand this really well, I did some readings using a board like this:

This is the Chromecast 850mA:

This is the Samsung Charger

And this connected to my laptop:

Of course those are just snapshots but at least on the Samsung one I see that it can go up until 0.134A


I know this doesn’t quite answer your question but this thread might be worth a read if you haven’t seen it yet.

Especially the topics raised in this post.

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Running QuinLED 32 and no problems. All my power supplies are over specked for power. I have too many sensors to power!