ESP8266 Community Forum

- Fri Jul 28, 2017 5:06 pm #68665 Hello,
can I wire it like this? Those are UltraNano Servos for my blinds and one thermometer is for outside and the other one for inside. Everything is working on my NodeMCU v0.9 but I would like to use v1.0 instead.
My mine concern is the amount of devices can I run from one pin...

Thank you.

- Fri Jul 28, 2017 5:52 pm #68667 How much current do the servos need?

- Fri Jul 28, 2017 9:20 pm #68668 I checked around for current specs and it seems to be something that is not typically listed. Of course it would be load and voltage dependent. But the torques is often listed and that too is voltage and load dependent.

I saw only one rating and it listed the stall current to be 360mA. That may be too much for the regulator on the board. It might cause a voltage drop that may cause a reset to the ESP8266.

I am assuming that you would not be running/changing more than one servo at the time. Making sure there is no overlap in operation might allow you to get away with what you planned electrically. Let us know of your results. I am interested in doing something like this as well.

- Sat Jul 29, 2017 2:27 am #68673 Most likely it is not necessary (and indeed not advisable) to power the servos from the µCs 3.3V (below specs, noise and spikes interfere with µC).
Most servos are designed to work on >4.8V (4xNiMH) and accept 3.3V Signals on their input, so power them from the "raw" pin.