MPPT Version 1.1

Autostart at Boot?

https://www.instructables.com/id/Nodejs-App-As-a-RPI-Service-boot-at-Startup/
requires
sudo npm install forever -g
to be able to run this as non-root user:
https://raspberrypi.stackexchange.com/questions/40105/access-gpio-pins-without-root-no-access-to-dev-mem-try-running-as-root
Three methods:
SysVinit
Systemd
Upstart
https://unix.stackexchange.com/questions/106656/how-do-services-in-debian-work-and-how-can-i-manage-them
Preferred:
Systemd
Examples:
https://www.raspberrypi.org/documentation/linux/usage/systemd.md
https://learn.adafruit.com/running-programs-automatically-on-your-tiny-computer/systemd-writing-and-enabling-a-service
https://nodesource.com/blog/running-your-node-js-app-with-systemd-part-1/

Support

Q: PC simulation getting serialport version error
Error: Error: The module '/node_modules/serialport/build/Release/serialport.node'
was compiled against a different Node.js version using
NODE_MODULE_VERSION 48. This version of Node.js requires
NODE_MODULE_VERSION 57. Please try re-compiling or re-installing
A: Possible solutions:

method 1

run your program with an older version of node by installing Node Version Manager nvm
git clone https://github.com/creationix/nvm.git ~/.nvm
cd ~/.nvm
git checkout `git describe --abbrev=0 --tags`
cd ..
. ~/.nvm/nvm.sh
Add these lines to ~/.bashrc
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm
Install and use different node version
nvm install 6
nvm use 6

method 2

Try completely removing node and reinstalling.
sudo apt remove nodejs
delete .npm folder in home delete .nvm folder in home delete package json lock file delete package.json file sudo apt install nodejs
try running
sudo node server.js
install node modules as requested
npm install express
etc