MB102 (white) power supply: Voltage stabilization for using with analog sensors?

I bought a MB102 (white) breadboard power supply to power analog MQ Gas sensors. However if I connect a sensor to A0 of my ESP8266 ESP12E Lolin v3 it prints crazy values like: 0, 125, 230, 1024, 1024, 1024, 1024, 1024, 0... And it stays at 1024 for a while and spikes to 0 and again to 1024.

When I measure the voltage directly from the MB102 output pins, my voltage meter jumps up/down 0,01 volt.

I checked that I use the analog output of the sensor and A0 of the Esp8266.

Anyone else can confirm unstable voltage supply? How could I stabilize the voltage so I can use the analog gas sensors?

Well of course, you have not given us any information here. You may imagine you have, but basically not. :astonished:

You may misunderstand what these "breadboard power supplies" actually are. They suffer the same limitation as the Arduino itself. They are not capable of powering anything other than the microprocessor itself and a few - and I do mean few - LEDs at 20 mA each if supplied with a 9 or 12 V adaptor. If supplied with a "Phone charger" with a 5 V USB outlet to the USB connector, they can probably feed through at least 500 mA to the breadboard pins; this has nothing to do with the on-board regulator.

Your gas sensor requires about 150 mA, way more than the capability of the regulator on the "breadboard power supply".

I checked the datasheet of the MB102 breadboard power supply again, and it states "maximum output current < 700mA". It says the same on the shop page where I bought it.

But I measured the output voltage at the pins without any load attached. And it was unstable as it jumped on the multimeter 0,01V up/down.

My question is: Is it normal for the output voltage to be unstable from the MB102? If someone has a MB102 at his lab, could you check if it outputs a stable voltage? Please. If you need any additional information from me, please tell me.

I power the MB102 with quality 2A USB charger and even tried 3 different ones, same results. I dont think its from the usb chargers.

Which output of the MB102 are you using? The 5V or 3.3V output?

WattsThat:
Which output of the MB102 are you using? The 5V or 3.3V output?

Both. And I measured each PIN. I just measured again:
3,28 ... 3,33 ... 3,35 ... 3,25 ...
5,16 ... 5,20 ... 5,18 ... 5,21 ...

The voltage reading is jumping on the multimeter. It doesn't stay. I checked the multimeter and its definitely giving correct readings.

I'm curious if someone has a MB102 (black or white) at their hands and could confirm or deny the jumping voltage?

I doubt the problem is with the MB102, it can provide more than enough stable power for the gas sensor.

You need to first test the nodeMcu. Do you have a 1K to 10K potentiometer? If yes, test by removing all connections to the board and power it using the USB connection. Connect the pot using the GND, A0 and 3V pins.

Pin A0 MUST connect to the center pin of the pot. Use this code:

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println(analogRead(A0));
  delay(1000);
}

The displayed value should change from 0-1023 as you rotate the pot. If it does not, the problem is with the ESP8266.

WiderstandZwecklos:
I checked the datasheet of the MB102 breadboard power supply again, and it states "maximum output current < 700mA". It says the same on the shop page where I bought it.

Well, if that is when you are powering it from say, a 9 V power supply to the "barrel jack", it would be sort of correct - it would supply up to 700 mA for a couple of seconds. Until the regulator heats up and shuts down

WiderstandZwecklos:
I power the MB102 with quality 2A USB charger and even tried 3 different ones, same results. I don't think its from the USB chargers.

Ah, well in that case, the regulator is not in circuit at all; what you are seeing is the regulation of the "quality 2A USB charger" itself, which is simply passed through directly (albeit via the switch) to the output terminals. Just look at the circuit diagram on the datasheet you cite. And on this particular module (of the many different ones available), there is no current limiting - it will pass whatever the USB charger can provide - 2 A, 3 A or more if the "charger" is so rated.