Embedded Programming for the Internet of Things

Embedded programming has a long history of making devices do what people need. However, it remains largely overshadowed by application programming. When application programmers were embracing relatively high-level object-oriented languages like C++ or Java, or graphical application development environments like MATLAB, embedded programmers were only moving from into C.  They were always outnumbered by app programmers. Today, even hobbyists can develop an app using an easy language and share it with the world, while embedded programmers need to have deep knowledge of hardware and firmware, and how to write programs that can execute in often highly resource-constrained environments. With the emergence of the Internet of Things (IoT), the balance can finally shift. Now that many new thermostats, toasters, watches and light bulbs are equipped with processors and connectivity, the market needs more embedded programmers to program these devices and simpler tools to allow these programmers to write code without plunging into the low-level hardware.

What Is Embedded Programming?

Techopedia offers a definition of embedded programming is "a specific type of programming that supports the creation of consumer-facing or business facing devices that don't operate on traditional operating systems the way that full-scale laptop computers and mobile devices do." The idea of embedded programming is part of what drives the evolution of digital appliances and equipment in today's IT markets.

In simpler words, embedded programming is designing and writing programs for small "computers" that are embedded within devices other than traditional PCs, laptops or smartphones. It's that which enables microcontrollers to awaken previously "dumb" devices—e.g. thermostats, lighting systems, parking meters, etc.—and give them some ability to "reason" about their environment.

Embedded Programming and IoT

From an engineering perspective, the Internet of Things describes a network of embedded, microprocessor-controlled devices, where that network is connected directly or indirectly to the web. The three pillars of IoT are, therefore:

1. Embedded programming
2. Network technology
3. Information technology

IoT is soon to be everywhere. Embedded devices are, therefore, soon to be ubiquitous as well.

Here is a brief glance at some of the ways in which IoT is changing industries:

• Industry — Industrial machinery and control, temperature monitoring and cognitive anomaly detection.
• Healthcare — Blood pressure monitors, heartbeat monitors, fitness trackers, embedded medication delivery.
• Aerospace and Defense — Flight control systems, actuation, air and thermal management, engine power monitoring and control.
• Smart Homes — Home security systems, digital cameras, televisions and kitchen appliances.

Image Credit: Sciforce

Diving Into Embedded Systems

Some say that every complex system in the world can be reduced to two conceptual spheres: software and hardware. An embedded system represents, more or less, the intersection of those spheres: hardware and software.

Exploring Embedded Hardware

A typical embedded development board is divided into five "modules": the processor, memory, input devices, output devices and bus controllers.

Image Credit: Sciforce

Hardware Components of an Embedded System

Processor

Embedded processors can be broken down into two categories: ordinary microprocessors that use separate integrated circuits for memory and peripherals, and microcontrollers that have on-chip peripherals, reducing power consumption, size and cost.  Some examples of these include:

• Microcontroller (CPU) — an intelligent device that computes the tasks assigned by the user and is used to build small applications with precise calculations.
• System on Chip (SoC) — comprises a CPU, peripheral devices (timers, counters, etc), Communication interfaces (I²C, SPI, UART), and power management circuits on a single integrated circuit.
• ASIC processor (Application Specific Integrated Circuit) — designed for a specific application by a company or manufacturer.
• DSP processor — removes the noise and improves signal quality in audio and video applications.

Memory

Memory is used to store data that's being used on the device. Some examples of the types of memory used in embedded systems include Non-Volatile RAM (Random Access Memory), Volatile RAM, DRAM (Dynamic Random Access Memory), etc.

Input Devices

Input devices, such as sensors, switches, photodiode, optocouplers, etc., capture data from the outside world to be processed or exported from the device.

Output Devices

Output devices, including LCD (Liquid Crystal Display) or LED (Light Emitting Diode) displays, seven segment displays, buzzers and relays, respond to input events from outside the microcontroller.

Bus Controllers

The bus controller is a communication device that transfers data between the components inside an embedded system. The most widely used bus controllers are serial buses (I2C, SPI, SMBus, etc.), RS232, RS485 and Universal Serial Bus (USB).

Exploring Embedded Software

Embedded software, sometimes called firmware, is written for the device drivers, operating system and applications, as well as for error handling and debugging.