The Arduino Uno has a maximum voltage range of 6 to 20 v and a recommended range of 7 to 12 v
Using it at 19.5 v may work if the power supply is well regulated but it is uncomfortably close to the limits and dropping nearly 15v across the linear regulator on the Uno may cause it to get fairly hot.
You can do it but you will have nothing left from the regulator for LEDs etc. The best solution is to invest in a buck converter, they are only a few dollars from your favorite china supplier, sometimes even less then a buck. While you are at it purchase two or three you can then use them to generate other voltages as you progress with the Arduino. I use ...
You could use a step-down converter to lower the voltage and also stabilize it to 12V or even lower and you wouldn't have any problem even if you power supply isn't really stable and outputs higher voltage.
(Instead of buying one you can even build it, it isn't really hard to make one)
Let me just give you an example of what happens even with 12V: One time I was working on a claw machine that I made for the Arduino and when I plugged in 12V while the 5V USB port plugged into the computer, guess what happened. Well, I'll tell you: the Arduino burned up and it was broken. I couldn't even put in the code because it was so cooked. I don't ...
I would suggest a barrel jack, you know, ones on eBay. For instance, those 2.1 x 5.5mm barrel jack connectors. Just solder the positive and negative wires respectively with barrel jack. Here is a link: eBay Barrel Jack
Make sure the red or the positive goes with the red on the Barrel Jack and that the black or negative goes with the black of the Barrel Jack. ...
This is a problem with the Teensy boards - or more correctly that the Jeelib Sleepy library does not support the Teensy boards.
You will need to modify the library to make it work for Teensy boards. Or you could use another low power/sleep library.
The grounds needed to be shared. The driver board ground needed to be connected to the Arduino ground. Otherwise your putting 17V in and only taking 12V out. Thanks to DaveNewton for this answer. I made this change and the torque was immediately fixed!
I am a bit confused you state: VIN output, that is the voltage input to the onboard regulator. For the power supply use one of the same voltage but capable of more current. Current is the maximum a power supply will give reliably. Current is the current needed by a load so if the load is less then the source and the voltages are the same it is a go. The ...
The esp family chips do not have EEPROM. Instead they just dedicate a small section of flash to pretend to be EEPROM.
That flash section, depending on the core version, is either a dedicated EEPROM partition, or a dedicated key in the nvram partition. Either way it's separate to the wi-fi credentials, which are stored in their own key in the nvram partition.
Powering the LED panels
Powering your panels will be your greatest challenge!
These LED panels are powered by a single +5V power input per panel and do not need a resistor in the power supply path (they actually need a very low resitance path). You do need a good quality +12V DC -> +5V DC power supply (or multiple, as explained below).
Since 3 x 256 RGB ...
You’ve probably switched some wires.
Relay Connection with Arduino, usually takes 3 Pins:
VCC / In (5v)
Signal (Data) - [D2] Pin On your sketch.
It is that simple.
Some recommendations apart from your question:
Make sure to know how your relay starts.
That is: Starts Always On or Always Off.
On your sketch (relay initialisation); set the initial ...