Pixelee:
First post! I am trying to build this project almost exactly hardware wise using Arduino Nano based on this tutorial http://natural-nerd.com/music-reactive-light/ .
In which case you will have to give details what is different; or even better, give the exact details (including schematic) of the hardware of your project. Any chance that you're using pins 0 and or 1 for something else than serial communication?
Pixelee:
The Code compiles without any problem as it is simply a copy and paste. The code is here: Natural-Nerd/arduino/soundsread2/sound_reactive.ino at master · hansjny/Natural-Nerd · GitHub
I also have downloaded the Fastled library. I made sure my board matches the Tool section....
...Arduino: 1.8.5 (Windows Store 1.8.10.0) (Windows 10), Board: "Arduino Nano, ATmega328P"
C:\Users\Michael\Documents\Arduino\LEDLIT\LEDLIT.ino:22:0: warning: "HIGH" redefined
#define HIGH 3
^
In file included from sketch\LEDLIT.ino.cpp:1:0:
C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino/Arduino.h:40:0: note: this is the location of the previous definition
#define HIGH 0x1
^
Although not the cause of your problem, definitely a bug.