ESP8266 Community Forum

- Fri Nov 18, 2016 11:03 am #58320 I have not done 100's of ESP8266 projects, but I've done quiet a few and the bottom line for the ESP8266 and any module that has fluctuating power requirements is the Z of the power output. With batteries this is the internal resistance under load. With any other supply like an LDO, it is the internal shunt resistance. For the ESP8266 to be stable, one must have a very low powersupply output impedance. In my projects, I use the $1 DC-DC "buck" modules from China ... that does the trick. Use a heavy gauge wiring that is as short-as-possible from the DC-DC to the ESP9266 ... DO NOT BREADBOARD POWER... those little pin jumper wires are great resistors!

Ray

- Fri Nov 18, 2016 11:51 am #58325 Thanks for some great hands on suggestions!

- Fri Nov 18, 2016 12:41 pm #58329 I don't know how you are feeding the chip, or what kind of capacitance you have, how it is connected. Implementation makes a difference. And the selection of the regulator as well. I had first used one that should have worked based on the regulator's ratings. But I did see too much drop, like you are seeing. Switched to a different regulator, with much the same max current spec, and the drop became smaller and acceptable.

And I can not stress enough how important layout can be. Taking good components but not laying it out well can reduce the possible performance.

I use surface mount capacitors with low inductance. Capacitor values from small, medium, and large. A few 0.1uF, 68uF tantalum, 470uF electrolytic.

One more thing. Voltage measurement with the scope has to be done right if you want to see short duration glitches. I connect the short scope ground lead to the ESP8266 case near the power pins and then scope the VCC connection point on the module.

- Mon Dec 26, 2016 11:45 pm #60003 > the voltage drops on my ESP-01 module almost 300mV.

As long as there aren't high frequency spikes and as long as the power voltage is in spec then this is no problem.