...Whether you are new to MongoDB or you just want to brush up on the core concepts, you can check out the Fundamentals section which features material on using the Node.js driver. The connection URI is the set of instructions that the driver uses to connect to a MongoDB deployment. It instructs the driver on how it should connect to MongoDB and how it should behave while connected. The Authentication Mechanisms guide contains sample connection code using each authentication mechanism supported in the MongoDB Community Edition. The Node.js driver uses the asynchronous Javascript API to communicate with your MongoDB cluster. ...
Set app volumes with real sliders! Arduino project to build hardware
...The sliders are connected to 5 (or as many as you like) analog pins on an Arduino Nano/Uno board. They're powered from the board's 5V output (see schematic). The board connects via a USB cable to the PC. The code running on the Arduino board is a C program constantly writing current slider values over its serial interface. The PC runs a lightweight Go client in the background. This client reads the serial stream and adjusts app volumes according to the given configuration file.