I have an ESP32CAM, a 3.7 Li-Ion battery hooked up to a HW-107 battery protection and charging board and a MT3608 voltage step up module. They are connected like the diagram shown below.

enter image description here

Now the following are the observations that were super annoying.

First I connected it to a HW-131 breadboard powersupply module.

**HW-131 (5V Terminal) Readings:**
5.18 V - Disconnected
4.87 V - Connected ✅

0.31 V consumed by the ESP32CAM

Batttery with HW-107 and MT3608 Readings:

CASE: 3.3V terminal of ESP32CAM

3.72 V - Disconnected
3.21 V - Connected (3.3V and GND of 5V) ☑️ [Camera sometimes produces artifacts]

0.51 V consumed by the ESP32CAM
NOTE: Repeating `setup()` loop when GND of 3.3V connected without any specific pattern!

CASE: 5V terminal of ESP32CAM

5.19 V - Disconnected
5.18 V - Connected (5.5V and GND of 5V) ❌ [Wifi.begin() causes the board to run the `setup()` repeatedly]

0.01 V consumed
NOTE: Same behaviour observed when Voltage regulator adjusted to 5.16 V i.e., drops to 5.15 V and Wifi.begin() causes the board to run the setup() repeatedly.


✅ - Works perfectly as it should
☑️ - Works but shows anomalies
❌ - Does not work

So the question is

Why the ESP32CAM module does not work (❌) when connected to a regulated 5.18V but works perfectly (✅) from the breadboard power supply module?

Refer to this thread.

  • 0.31 V consumed by the ESP32CAM ... no ... the voltage is consumed by the HW-131 ... and also by the breadboard, depending on where the voltage is measured ... internal resistance in the HW-131 and in the breadboard creates a voltage drop when current flows ... increasing the current results in an increased voltage drop ... research ohm's law
    – jsotola
    Commented Jun 8 at 17:17
  • The serial output from the esp32's boot report may contain useful information to include in your question.
    – timemage
    Commented Jun 8 at 21:48
  • @jsotola Every voltage reading is measured across the terminals of the ESP32CAM connected to the Voltage Boost Module. But I feel a concept of Ohm's Law in this context that is foggy to me is that, when powering the module, the internal resistance is constant, so a specific voltage applied (may it be from a battery or stable USB cable) should create the same amount of current, yes? According to V=IR ? So why is the breadboard module working fine but the battery with the boost voltage is not even when a 5.18V is applied? Commented Jun 9 at 3:05
  • 1
    MT3608 can introduce noise and ripple into the power supply. This noise can cause instability in sensitive components like the ESP32CAM.Place a 100µF electrolytic capacitor and a 1µF ceramic capacitor in parallel across the output of the MT3608 module. This will help stabilize the voltage and filter out high-frequency noise.You can also try pixycam instead. theengineeringprojects.com/2015/11/…
    – tepalia
    Commented Jun 9 at 15:15
  • 1
    I only came across some threads like this: forum.arduino.cc/t/esp32-cam-is-flickering-why/1168042 Unfortunately the official doc does not discuss how to eradicate noise. docs.espressif.com/projects/esp-faq/en/latest/…
    – tepalia
    Commented Jun 10 at 12:12

1 Answer 1



The MT3608 has a maximum of 2A. When Voltage is increased, the current is decreased (apparently this is how Voltage Boosters work). The ESP32CAM unfortunately needs 5V 2A to function properly. So when the Voltage is stepped up by the boost module, the current gets stepped down to around 1A. Hence, causing a "brownout" in the ESP32CAM (❌). In case of 3.72 V connecting via the boost module, the currrent stays near the 2A mark, hence making the camera drunk but still working (☑️) as it is mentioned it the datasheet of ESP32CAM.

Refer to this video to understand how voltage boost converters in general work.

  • apparently this is how Voltage Boosters work ... no, that is how the universe works ... you cannot create energy out of nothing ... power out cannot be larger than power in, and there are also some losses, so the power out is less than power in
    – jsotola
    Commented Jun 9 at 17:26
  • @jsotola Can you please suggest what is the best way to get a 5V 2A regulated output? Commented Jun 10 at 4:13
  • 1
    depends on your definition of best ... maybe buy a 5 V, 5 A power supply ... a little extra current capacity for developing future projects ... when a project is complete, then buy a power supply to fit its requirenent
    – jsotola
    Commented Jun 10 at 4:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.