ESP8266 Community Forum

- Thu Jan 05, 2023 3:15 am #95712 Hello,

I am trying to run a ESP-01 with a PIR sensor powered by an 18650 3.7 V battery

I have used:

• HT7133-1 LDO regulator 3.3V
• 1000uF 10V Capasitor
• 100nF Ceramic Capasitor

As in the sketch below.

When the switch is off voltage is stable at 3.3V but as soon as I turn on the ESP-01 voltage starts to drop gradually to around 1.5 volts and ESP switches off. I am not experienced I could use any help thanks in advance.

Last edited by aphlox on Fri Jan 06, 2023 2:40 am, edited 1 time in total.

- Thu Jan 05, 2023 7:45 pm #95714 What PIR sensor are you using? I suspect that is the culprit.

Also where is your negative/GND power supply connection? Nothing seems to be going to the negative/GND power rails from the LDO

- Sun Jan 08, 2023 1:06 am #95725

What PIR sensor are you using? I suspect that is the culprit.

Also where is your negative/GND power supply connection? Nothing seems to be going to the negative/GND power rails from the LDO

I am using HC-SR501. But even if I disconnect the PIR sensor ESP-01's voltage still drops.

Ground connection is there I forgot to draw it I updated the skecth.

- Sun Jan 08, 2023 5:17 pm #95736 Does the ESP-01 board have a LED? Is it on when you turn on the switch?

Would be really good to see the current draw - can you wire a multimeter into the circuit?

Also what is your sketch doing? If you have the wifi turned on then the current draw is quite high