Understanding The Embedded Software Development Cycle

Joseph Sibony
Joseph Sibony reading time: 8 minutes
August 8, 2022

Embedded software shares a few similarities with standard software, but it also has some tricky little quirks and constraints that make it a unique challenge for any developer.  

That’s why we’re diving deeper into the embedded software development cycle today; to find a framework that can help dev teams build strong, secure embedded software that end users can really rely on.  

What makes embedded software development different? 

In standard dev cycles, the software is the star of the show; the hardware is there to house the software and make it easy to interact with, but it’s not the primary focus.  

But, with embedded software, the hardware and the software go hand-in-hand. They’re completely intertwined, and equally important.  

That means embedded software developers have to work around a few unique requirements. 

First of all, every line of code in an embedded software application needs to fit the constraints and composition of the hardware. So your dev cycle must consider everything from the weight of the hardware to how the hardware will interact with other systems. If your embedded software has an AI component, there’s even more to consider, from chips to data pipelines.  

Secondly, as embedded software increasingly finds its way into more critical infrastructure – things like self-driving cars and traffic lights in smart cities – safety is paramount. That means embedded software developers need to consider everything from local regulations to company health and safety rules. Since cyber attacks on IoT devices using embedded software have become terrifyingly common, data security is a major priority too.  

Thirdly, embedded software is, by its nature, hard to update once it’s rolled out. For one thing, most embedded software runs with little (if any) intervention from end users. That makes it hard for users to break the software, but also makes updates tricky; if you need to patch your software, you’ll have to allocate a programmer to initiate the update and check that it runs smoothly. If your software needs many updates, you could lose hundreds of hours in rolling it out.  

And it’s not just the lack of user intervention that makes embedded software hard to update. Embedded software most often shows up in ‘always-on’ tech, things like security sensors, factory machinery, and healthcare devices. That means that updating the software – even if it’s installed quickly and only requires a quick restart – can be hugely disruptive. That means updates really should only roll out when they’re absolutely critical for performance; you can’t afford to be rolling out new patches every month.So, the stakes are often higher, the regulations are often trickier, and the margin for error is razor-thin.[Text Wrapping Break] 

Let’s take a look at how you can navigate these challenges and still build outstanding embedded software. 

Step 1: Scoping (AKA the who, what, when, where and why) 

It’s one of the most important rules of software development: don’t start building software until you know exactly who you’re building it for.  

So, this is the time to get really specific about: 

  • Who’s going to be using this software?  
  • What problem will it be solving? What need is it fulfilling? 
  • How are they going to use the software? Think about when and where it will be booted up, how long it needs to run for, and how that might change the kind of software you build.  
  • How much will customers pay for the product you’re building?  

The answers to these questions are going to be your north star for the rest of this software development cycle, so don’t rush through them or skip over them. You’ll need to keep coming back to this research to make sure you’re on the right track.  

Step 2: Design (AKA plotting, planning and building a team) 

Now that you know the need you’re fulfilling, it’s time to start fleshing out the specs for your device and the software that goes with it.   

The idea here is to figure out how your hardware and software can work together to maximize performance.  

That means you should be in constant communication with the team developing your hardware, so you can figure out the right combination of:  

  • Tools – You’ll need software development tools that can support the unique needs of embedded software development. That means embedded software development tools that are secure (so your end users are protected), adaptable (so you can react fast when the needs of the hardware evolve) and that accelerate the dev process. You’ll also need to choose a project that will help your Linux build move as fast and efficiently as possible (we recommend Yocto – you can read more about why here). 
  • People – The kind of device you’re building and the makeup of your team will determine the mix of hardware engineers, embedded software engineers, developers and electrical engineers – not to mention a host of other roles – you’ll need on your team. This is a good time to figure out if you need extra support some a company that offers embedded software development services. 
  • Hardware and software requirements – It’s time to create a detailed technical spec document for your device. Here is where you’ll define the purpose of the product, make a list of the main features, and figure out manufacturing requirements (size, weight, operating voltage, memory types – everything you can think of).  

This is also a good time to set out your team’s metrics for success, so you can measure your performance and gather the nuggets of data that will make your next dev project even better. 

Step 3: Building (AKA one step forward, two steps back)  

Now it’s time to see if all that planning has paid off. Are there any unexpected snags in the design of your software or hardware? And do both components work together in perfect harmony?  

The hardware usually comes first – as we’ve explored, you’ll have to adapt the software to fit the hardware, so it makes sense to have the physical form of the device nailed down as much as possible before you start developing the application.  

That means the hardware engineers get to develop an alpha prototype based on the system architecture developed in the last step. They’ll use this to check that the system architecture works in practice, and probably make some tweaks to the design to iron out any issues before they build the beta prototype.  

Then it’s time to start coding your embedded software.  

Of course, there’s a lot of complexity hidden in that simple sentence. You’ll be trying to work around rigid hardware requirements, meet stringent security requirements, and deliver all of the functionalities in your tech spec.  

But that’s only the beginning. 

Step 4: Testing and fine-tuning (AKA everything, everywhere, all at once)  

As we discussed above, firmware is incredibly tough to update once it’s out in the world and in the hands of end users. That’s why it’s crucial that you test your code thoroughly, from every angle, before you move to the next stage.  

This is where the dev tools you’ve chosen can make or break your software.  

In short, you need tools on your side that act like rocket fuel for your dev process – tools that let you develop new iterations, test them out and move onto a better, stronger iteration at breakneck speed. And, most importantly, you need to be able to do all of that without chipping away at the quality of your code or the security or reliability of your software.  

That means you should be looking for a tool that can:  

  • Accelerate compute-intensive development tasks like compilations, CI/CD builds, QA testing, code analysis and API tests 
  • Allow you to iterate fast and scale up without sending your IT overheads through the roof  
  • Do both of these things without forcing you to change your usual processes or undergo tons of training 

Usually, that means you’ll need a tool like Incredibuild: one that uses a combination of powerful distributed processing, virtualization and unique build caching to help you build and test at lightning speed.  

With less time spent waiting for code to compile or tests to run, you’ll be able to really dive into continuous integration, get feedback to devs faster, make your resources stretch further, and really make the most of every second of dev time 

And that means you’ll be able to really explore every avenue and stress-test every line of code, so you can move to the next stage of the process with confidence.  

Step 5: Field testing (AKA wind, rain, heat and technophobes) 

It’s time to see if your software can clear the final hurdle; working reliably, securely and efficiently when it’s out of the lab and into the hands of end users.  

At this stage, set aside some time to test how your software and hardware function in context. How does your software hold up when it’s being used by laypeople? How does your hardware run when it’s in a warm environment, or when it’s exposed to normal wear and tear?  

Use the information you gathered at step one to test your devices in the context in which they’ll be used. If you’re building a smart sprinkler, check that the hardware is rugged enough to stand up to the elements. If you’re building a medical device for EMTs, make sure that your software boots up quickly and can run effectively, even when ambulances have to visit remote areas with low connectivity.  

The key to outstanding embedded software? Test, test and test again 

If you’re building embedded software, you need to be ready for more complex needs, tighter restrictions and less room to make mistakes.  

That’s why – although every stage of the dev cycle is important – giving yourself the tools to test fast and iterate faster is absolutely crucial. In the course of development, you’ll need to test everything, everywhere in your code – if not all at once, then certainly as quickly and efficiently as possible.  

It’s the best way to make sure your stand up to anything, so your end users can rely on it completely.  

Joseph Sibony
Joseph Sibony reading time: 8 minutes minutes August 8, 2022
August 8, 2022

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