Servo wiring Wemos

Hi. I have the Arduino knock off, Wemos D1 R3 (not the mini), Arduino compatible. I also have the 329TG servo by Powerhobby. The power input for the servo is 6-8.4vdc. To test, I have a 6v wall wart power supply. I can't figure out what pin the signal line should be connected to. I have successfully programed a sweep code to the Wemos using the Arduino IDE and tutorials how to upload to it. The pinout is a bit different from an Arduino.

Painfully impractical board, i am afraid! Really should never have been made! :roll_eyes: Missing too many usable I/O pins.

Try the "Any" pin! You have a reasonable selection, just need to get the pin numbers to match. I presume the 3.3 V logic level is generally adequate to control a servo.

i plan to use a separate power source to power the servo. it requires 6-8.4v. 9v wall wart power for the wemos, then just the signal line is left from the servo. ill try to match up pins. thx.

I can't get any of them to work on the signal line. The wemos is powered with 9v via included jack. servo with 7.4v on it's power supply. Then tried the signal line on that whole side of the D1. WTF.

Maybe not then.

Use a 74HCT14 with two buffers cascaded as a level converter to develop a 5 V signal for the servo.
Powered by 5 V, with a 0.1 µF capacitor directly across its power pins.

I don't have a 74HCT14 so I'll need to order. I feel like I should have just got the UNO.

Do you have anything like a 74HC14/ 74HC04? Any of these should work. even a 74HC00 or any general gate chip.

Don't get a UNO. Very impractical. Nano is the "go-to" Arduino which you can use with a breadboard/ stripboard/ custom PCB, if you no longer need USB for programming or serial monitor, a Pro Mini. :+1:

Okay, I got pins figured out, I think. The servo does this vibrating, back and forth fidgety type of thing while trying to move in the 180 degree direction. I'm using 8v with the power supply to the servo now. What's happening?

Ouch. Hopefully you didn't blow it up yet.
Better use a 5volt cellphone charger, connected to the USB socket.

A 329GT seems to draw about 3 Amp stall (starting to move) at 8volt.
You get these problems if the supply can't provide at least that current.

the wemos should be able to take more than 9v using the jack. i was actually wondering about the stall current on the servo and couldn't find anything on it. so the 329tg can take 6-8.4v, and 3A supply. thx.

Hi. So I got the 8v 3a power supply today. Same result. What else can I try? I could do a vid for you if you like. Thx.

What about a cap? I see they are being used in some situations to smooth out behavioral issues in the servo. Just thinking.


I have a little servo, the g90 I believe. I'll wire that up to the wemos and see what result it gives. If it works fine, then bad servo potentially, if same result, then some kind of power supply , connection, or software code issue. Seams reasonable.