ESP8266 Community Forum

- Sun Feb 07, 2016 4:21 pm #40647 Capacitors are not like resistors : 2 capacitors in series make them divide resulting value them but it is adding voltage values. You should make them connected in parallel to add values (100uF+100uF=200uF).
And Yes ! Plus on VCC, Minus on GND.

For PullUp, it means Up for VCC, so connect resistors, one for each pins (so 3 resistors here), one side to the pins, other side for VCC.

- Sun Feb 07, 2016 7:05 pm #40652 Well, I did what you suggested. At a first look it seemed to work ok. I got the LED blinking, maybe 10-15 times. Then it stops.
Restart the module, same thing. Arghhhh.

I then connected my Multi Meter to watch the Voltage (should have done long before). With the 2 Capacitors, GPIO0 not connected, I have 2,15 V???

GPIO0 to GND, disconnect VCC and re-connect: 2,91 V.

Compile and upload: 2,99 V. Disconnect GPIO0: stable 2,95 V. Power off and on again Voltage drops to 2,34 V, which is probably to low for proper Operation?

This is with the USB Power from my Sony Vaio Laptop. But I also tried an active USB Hub that says it provides 5V 3A.

Just to be sure I did it right. This is how i connected the capacitors (labeled cd11x)


VCC-----x------x------>
I I
100uf 100uf
I I
GND---- x----x------<


BTW: though it seems to have not enough power to run properly, at least it has enough power to mess up my wlan .......

- Sun Feb 07, 2016 9:09 pm #40654 So, you power the ESP from the USB, even when you tried a Powered SUB-Hub ?
You should try powering directly from a Wall-Plug adaptor along with 3.3V Voltage Regulator like AMS1117.

- Mon Feb 08, 2016 6:15 am #40677 Good Morning,

since I saw videos on youtube from ESP' s running on a 3V Battery, I never thought that an USB Port would not supply sufficient power to drive an ESP.

I was wrong! I now have used an external power supply and the ESP_s runs like a charm.

Thank again you for your patience and help

.. ernst