Every day, people face and use dozens of devices whose functioning relies on microchips and circuit boards. These are gadgets with built-in software, such as photo cameras, fitness trackers, coffee machines, etc. Since many of them perform critical functions for some spheres of life, embedded software remains a hot topic.

If you want to find a reliable embedded systems company to implement your idea of a smart digital device, you need to know the basic facts about embedded software programming.

Introduction

First, it should be noted that the development of traditional apps we install on laptops or smartphones differs from the creation of embedded software. Desktop or web applications are detached from the hardware they run on. In this case, the major task of app developers is to implement the logic that would ensure software functioning, and it doesn’t matter on what device this app will be installed.

On the contrary, embedded software is tightly connected with the equipment it runs on, and each line of built-in code can affect the hardware at the physical level. That’s why software engineers must be able to read a circuit, data sheets and other documentation for electronic parts, understand the hardware component features and their interconnections. 

Embedded System Definition   

A real-world device with a programmable part based on a microchip that performs one or several pre-defined tasks is called an embedded system.

Components

Various systems may have various constituents relevant to the tasks they are supposed to perform and external requirements they operate in. However, there are two groups of obligatory components in any embedded system.

Hardware

This includes all physical parts composing the system:

• Body frame 
• Central processing unit 
• Actuators 
• Memory devices 
• Signal converters 
• Input/output devices 
• Sensors 
• Cameras, scanners, modems, and other external equipment

Software

The software layer processes the information received from sensors and other physical elements and makes the system work. This may include the following pieces of software embedded in the hardware:

• Firmware 
• Operating systems
• Drivers
• Middleware
• User application with an interface

Note that some solutions can do without middleware or OS, it all depends.

To build an embedded system, you should first decide on hardware parts, integrate and configure them, and then develop software according to this configuration. This means that a development team should comprise both specialists with strong hardware engineering skills and software programming experts. 

Types of systems

The first group is distinguished according to the level of system independence:

• Stand-alone — function independently (e.g., an electronic thermometer). 
• Networked — operate due to the network connection and are also called IoT systems (e.g., a smart home lighting system).

The second group is distinguished according to the level of system complexity:

• Small — use very little power resources and have primitive software.
• Medium — solutions with more complicated software which needs more resources. 
• Complex — large and tricky solutions performing complicated, critical functions.

The third group is distinguished according to the system responsiveness:

• Real-time — must perform tasks within limited time frames, and this is critical (an example is intensive care equipment). 
• Non-real-time — have no responsiveness limits.

Features 

All embedded systems, though differ in functions, share some characteristics.

• Microprocessor/microcontroller is a chief component. 
• Task-specific functionality of all built-in systems means they execute pre-programmed repeated functions throughout their lifecycle. 
• Use specific operating systems or may function without them. 
• Solutions with built-in software are resource challenged, meaning they are designed to operate in conditions of limited hardware resources. 
• High reliability is an obligatory characteristic needed to ensure the consistent responsiveness of embedded devices.

General Development Process 

Embedded software developers should work closely with hardware engineers to create a successful embedded solution.

Joint design

Hardware engineers select the components needed to build a system. At this point, software developers join them to make sure they pick the right parts that will be able to provide the desired application functionality.

Design review

Once the circuit diagram is ready, the developers work with the circuit designers to ensure that all signals and connections are correct and work as originally planned. 

Hardware emulation

Then, developers create a test module or hardware emulator that will emulate signals and allow you to see the minimum functionality of the embedded software. This way, you can quickly iterate and develop separate code components.

Board testing

Once an assembled board is ready, embedded system designers test its main functions to see if it can be powered on, if the board communicates correctly with peripherals, if the correct voltages are configured in the converters, etc. 

Assembly of drivers

If your project device is supposed to connect any peripherals or accessories, it needs a set of drivers. Good drivers are the backbone of any device. It’s better to spend more time writing good drivers than modifying code every time you need to add an external component (scanner, camera, etc.). 

Logic implementation 

The last stage of the development process is when developers implement the logic in code that causes the device to do what it was designed to do. They are guided by specifications the hardware engineers prepared. At this stage, the device should start working, and you will only have to improve the code. Of course, development may involve multiple prototype iterations, and for each iteration, you will need to refine the code.