Zephyr Plus ModusToolbox Puts the Power in the Hands of the Developer
June 09, 2025
Sponsored Blog
Infineon has built quite the Bluetooth resume over the years, and with the launch of support for the Zephyr OS in our latest Bluetooth® LE MCU, the AIROC™ CYW20829, we are opening the door even wider for developers. And with the number of applications growing almost daily, such support is welcome. Applications today include game controllers, PC peripherals, wearables, electronic shelf labels, asset tracking, and automotive applications such as car access, tire pressure monitoring, and battery management systems.
Starting with Zephyr OS 3.7.0 (released last Summer), engineers now have two clear options for development: the open-source Zephyr OS with its native Bluetooth® LE stack, or Infineon’s own ModusToolbox™ ecosystem featuring the mature, feature-rich AIROC™ Bluetooth stack, which contains all of the latest Bluetooth LE features, and even some advanced features not yet released by the Bluetooth SIG. ModusToolbox™ is an extensible development ecosystem that supports an array of Infineon microcontrollers. Hence, there’s a good chance that you are already using the software.
Zephyr, the Obvious Choice
It should not come as a surprise that Infineon chose to support Zephyr. The development community asked for it, and we delivered. Open-source platforms like Zephyr offer a host of independences, such as freedom from vendor lock-in, freedom to reuse code across hardware platforms, and freedom to pivot if the supply chain throws you a curveball. Remember what happened during the Covid pandemic and subsequent capacity constraints that came with it?
One of the beauties of Zephyr is that it abstracts the hardware behind a unified HAL and Bluetooth® stack. That means you can build once and deploy across an assortment of MCUs with minimal rework required. That’s huge when your project timeline doesn’t leave room for surprises. And when it comes to security, open source (and Zephyr) is the right choice. Simply stated, the more people who come across the code, the safer it is, as it receives scrutiny from a diverse group of engineers, with far more chances to catch bugs, and stay on top of security advisories and vulnerabilities.
There’s also the open-source factor itself. For teams leaning into open development, Zephyr checks a lot of boxes, including:
- fast evolution from a global development community
- transparent code scrutiny and patch velocity
- flexible toolchain support
- easier onboarding with a great deal of community-tested code examples
Stick with ModusToolbox and the AIROC Stack
In most scenarios, you will need full control over your Bluetooth LE application, and that’s where ModusToolbox shines. There’s a reason Infineon’s stack powers products in everything from PC peripherals to wearables to automotive. It's optimized, and packed with the latest Bluetooth LE features, and lets you get under the hood to tweak the firmware and stack for performance. In some instances, it’ll even contain pre-release versions of software, obviously clearly marked as such.
Here's a summary of Bluetooth® development options, from Infineon and the community at large:
| ModusToolboxTM / AIROCTM | Zephyr® OS | |
| Project type | Better for complex applications | Better for basic Bluetooth LE applications |
| Coding | Good for implementation flexibility | Good for porting to multiple chipsets |
| Software features | Access to Infineon Middleware | Supported by Zephyr community |
And Infineon’s ModusToolbox doesn’t stop with Bluetooth. Actually, far from it. CAPSENSE™, SmartIO, Secure Policy Configurator, and device-specific tuners are all included. At the same time, the AIROC stack boasts a track record that’s second to none when it comes to ultra-low-power, high-performance applications. The bottom line is that Zephyr makes a great choice for an OS, but the end-product development must go a lot further than the choice of an OS. And ModusToolbox and the AIROC stack will help you get over the finish line. That’s particularly true when you’re looking at products filled with bleeding-edge features.
Conclusion
With Zephyr support now available for the CYW20829 MCU, developers get the best of both worlds. If you desire portability and an open-source ecosystem, Zephyr has you covered. And if you need full-stack control and advanced features, ModusToolbox is your tool of choice.
To be very clear, Infineon is not forcing you down a particular path. The choice is still (and always will be) yours. We are just enabling you to make the best choice when it comes to choosing your stack, building your app, and getting your product to market faster.
