#653 – Benjamin Cabé Nose Zephyr

Welcome Benjamin Cabé of The Zephyr Project!

• Benjamin is the developer advocate at The Zephyr Project, which is both a Real Time Operating System and an ecosystem (or almost like a “distro”, rather than an OS)
• Benjamin does videos on the Zephyr YouTube and maintains an awesome blog / newsletter
• The ecosystem is deep: Chris recently learned there is a state machine framework
• Multiple people involved in dev like an OS
• The Platinmum Members includes chip companies like NXP, Nordic, ADI
• There are 600+ boards supported in the ecosystem (and more if you do custom)
• Devicetree is a tough concept, but a powerful one that was borrowed from Linux
• Who is the audience for Zephyr?
• Chromebook embedded controller
• What’s the smallest processor that Zephyr can run on? M0s can run it no problem
• Chris thinks one of the benefits is the ability to bolt new stuff on to a project
• Simulation through Wokwi (Past Guest Uri) or Renode (Past Guest Michael)
• Using different levels of abstraction
• zephyr i2c init
• Benefits of abstraction
  • Swapping out chips (bubblegum tapshoes)
  • Tying stuff together (bolting stuff on)
  • Infrastructure with CI/CD
• Zephyr doesn’t have an official IDE but VScode “just works”
• Helper tools from Nordic
• Open Source
• Hobby projects
• Dev survey
• Custom Keyboards (ZMK)
• RP2040 support
• Arduino recenlty joined the project
• Layers of abstraction
  • Architecture (ie. arm, nios2, x86)
  • SOC (available peripherals surrounding the core)
  • Board (PCB definition which might have:)
    • SOC
    • Memory
    • Peripherals / Sensors
• Check the tree and PRs for sensors that might be in-flight
• Compared to Arduino IDE
• Choosing ecosystems
• Weekly newsletter
• Things you didn’t know you needed: NMEA subsystem
• In Jay Carlson’s 2nd appearance on the show, he said “I’m reading more code than I’m writing”
• Benjamin’s profile photo is of his artificial nose he created a few years ago
• Making a machine model for bread (pandemic)
• It uses TFLite
• What is the project doing? (in parallel)
  • Acquire data
  • Machine learning inference
  • Display update
  • Network interface
• Benjamin reimplemented the Nose in Zephyr using ZBus (Chris recorded a video with the author of this subsystem)
• Like an MQTT broker on device
• Some of the concerns I (Chris) had when I was starting was not understanding RTOS concepts (threads, queues, etc). Brian Amos was on the show talking about his book, which is a great way to get started with these ideas.
• Threading / work queues
• The importance of a project when starting out
• Starter hardware
  • Hero devkits (Chris likes the nRF9160-DK as a starter board or the nRF5340-DK)
  • M5stack boards
  • iMX8
• Jumping down to Zephyr from Linux
• MPU + MCU
• Tight integration
• Zephyr can run POSIX code
• What about the the RT in RTOS? Does this operate realtime often? (timing critical)
• BOM cost and software cost
• Security and dependencies
• Join the Zephyr discord to talk to other people using Zephyr
• TechTalks / YouTube
• Interested in going to a conference in Seattle in 2024 for Zephyr? The ZDS / EOSS CFP is open now!