#556 – Firmware for Hardware Engineers with Phillip Johnston

Welcome Phillip Johnston of Embedded Artistry!

• Phillip was on episode 290 of Embedded.fm
• Phillip’s firmware experience started at a military contractor. He also had a programming background from high school.
• The minimum product is a bootloader and has remote firmware update capabilities
• General guidelines and design methodologies for writing better firmware
  • Separation of concerns: break things down smaller
  • How to hide information
  • Loosely coupled to the hardware
• “How can I make this smaller?”
• “Can I test this without the hardware?”
• Either James Grenning / Jacob Beningo talk about “There is no spoon” and hardware is just another dependency.
• Flex paging system example
• Recorded data over the radio
• Continuous Integration (CI)/ Continuous Deployment (CD)
• Test Driven Development (TDD) is a well known software engineering concept that James Grenning teaches for embedded development
  • Start sketching out on the computer first
  • What interfaces do I need to create
  • Interface with sensors using a direct interface from the desktop like the Aardvark
  • Isolating someone else’s code into its own box
• Writing it using x86 based GCC or CLang
• Forces you to think about dependencies
• Lager data episode with Akbar (hardware in the loop testing)
• Setting up tests
• E&O insurance
• What does a test suite look like?
• Phillip uses Jenkins for his build system, but there is also GitHub actions, circleCI, travis
• Hardware in the loop test
• When should people start CI?
• Need to build from command line
• Automated systems allows you to leverage yourself
• Embedded Artistry has Courses that teach people how to build systems for their embedded systems
• Design for Change is an upcoming course
• Putting the pipeline in place
• Start by checking code on the server
• Having a shell on the device
• What does ‘best’ look like?
• Mixed metaphors in software
• Dealing with multiple PCB builds
• Dwigt
• What happens when the complexity goes up (networking interface)?
• Testing in more difficult environments
• nRF5 SDK to Zephyr
• Treat an RTOS like any other dependency
• Zephyr
• Low power seems to be lacking

Links from Embedded Artistry that our listeners might find useful, not already linked above:

• Embedded Artistry
  • Welcome – for people unfamiliar with us, this is a great place to start
  • For Beginners – mentioned in the podcast
  • Newsletter – we send out a monthly industry update along with other embedded-related emails
  • Course Library
  • Membership Information
• Consulting