Node-RED is an easy-to-use programming tool to develop apps with minimal or no coding. It’s browser-based interface provides a rich set of pre-built modules, called nodes, that can be used in a drag-and-drop interface to quickly develop an application.

In this tutorial, we’ll look at how to develop an SMS app using Node-RED on the Raspberry Pi platform. For this SMS app, we’ll create a simple UI for the user to input phone numbers and messages using Node-RED’s form node. We’ll use function nodes to do post-processing of user input. Node-RED has built-in nodes for serial communication, and we’ll use them to write serial data to the modem port.

Setup for this tutorial consists of RaspberryPi 3 with a Huawei 3G USB Modem, which is connected to a cellular network.