Developing embedded software differs from developing application in many ways. The most obvious difference is that there is usually no display available in embedded systems whereas most application software would be useless without a display to communicate with the user. Another difference is that it can be challenging to know whether the software for an embedded system is performing the correct functions for the right reasons or if it is performing what appear to be proper functions coincidentally. This is especially relevant to closed-loop control systems that include multiple types of sensors in the control loop, such as with fully autonomous systems.
Back when I was building fully autonomous vehicles, we had to build a lot of custom development tools because standard software development tools just did not perform the tasks we needed. Some of the system-level simulations that we used were built from the ground up. These simulations modeled the control software, rigid body mechanics, and inertial forces from actuating small rocket engines. We built a hardware-in-the-loop rig so that we could swap in and out real hardware with simulated modules so that we could verify the operation of each part of the system as well as inject faults into the system to see how it would fare. Instead of a display or monitor to provide feedback to the operator, the system used a telemetry link which allowed us to effectively instrument the code and capture the state of the system at regular points of time.
Examining the telemetry data was cumbersome due to the massive volume of data – not unlike trying to perform debugging analysis with today’s complex SOC devices. We used a custom parser to extract the various data channels that we wanted to examine together and then used a spreadsheet application to scale and manipulate the raw data and to create plots of the data that we were looking for correlations in. If I was working on a similar project today, I suspect we would still be using a lot of same types of custom tools as back then. I suspect that the market for embedded software development tools is so wide and fragmented that it is difficult for a tools company to justify creating many tools that meet the unique needs of embedded systems. Instead, there is much more money available from the application side of the software development tool market, and it seems that embedded developers must choose between figuring out how to use tools that address the needs of application software work in their project or to create and maintain their own custom tools.
In your own projects, are standard tools meeting your needs or are you using custom or in-house development tools? What kind of custom tools are you using and what problems do they help you solve?