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IoT Zephyr

Zephyr Weekly Update – Zephyr 3.6.0 is a go, Hello 3.6.99!

Zephyr 3.6 was released a week ago and it is really amazing to see how well it was received. I am particularly happy to see that thousands of people have already watched the video highlighting some of the changes and additions available in this release, such as the added support for GNSS receivers, keyboard matrix driver, and more. Please check it out if you haven’t had a chance already!

I also encourage you to check out our special Zephyr Tech Talk episode earlier this week!

Zephyr 3.7, which will be the next Long-Term Support version of the project, is already starting to shape up, and below are some of the highlights from the first couple hundreds of commits already merged into the main branch.

Native UART TTY driver now supports interrupt-driven API

In an effort to make it increasingly easier to emulate Zephyr on host systems, the native UART TTY driver now supports an interrupt-driven API. In order to use the new driver for your zephyr,native-tty-uart UARTs, you may simply enable CONFIG_UART_INTERRUPT_DRIVEN in your project configuration.

I find it particularly interesting as this means that it’s now easier to e.g. simulate a GNSS receiver on your host system, by attaching your Zephyr app to a virtual UART into which you can inject your mock NMEA sentences. (PR #68857).

Boards & SoCs

As the project is in the process of transitioning to a new model for describing the SoCs and boards in the source tree, no work has been merged in the main branch this week.

The maintainers are holding off with adding new boards/SoCs and making changes in main until the working branch (collab-hwm) where the migration is happening is ready to be merged (which should be very soon).

General drivers

  • An interesting new input driver allows to define input keys that are implemented using an ADC and a resistor ladder.
Image credit: ignorantofthings.com

This is a pretty clever way to add multiple buttons while only using a single ADC channel, and the driver allows to basically define the mapping of how each ADC values / voltage ranges correspond to each key, or key combination. (PR #68446)

/ {
        buttons {
                compatible = "adc-keys";
                io-channels = <&adc 2>;
                keyup-threshold-mv = <0>;
                key_0 {
                        press-thresholds-mv = <1650>,  /* KEY0 */
                                              <2536>;  /* KEY0 + KEY1 */
                        zephyr,code = <INPUT_KEY_0>;
                };
                key_1 {
                        press-thresholds-mv = <2300>,  /* KEY1 */
                                              <2536>;  /* KEY0 + KEY1 */
                        zephyr,code = <INPUT_KEY_1>;
                };
        };
};
  • RRAM (or ReRAM, Resistive Random-Access Memory) is a type of non-volatile memory that stores data by changing the resistance across a dielectric solid-state material. It’s a relatively new technology and one of its benefit is that it is several orders of magnitude faster than flash memory.
    A new flash driver for the RRAM controller found on some Nordic nRF SoCs has been contributed this week. (PR #68309)
  • New regulator driver for the Cirrus CP9314 buck switched capacitor DC/DC Converter (cirrus,cp9314). (PR #68177)
  • New driver for the ScioSense ENS160 environmental, multi-gas, sensor (sciosense,ens160). This sensor allows to measure CO2, VOC, as well as a general air quality index (AQI). (PR #67343)
  • The PixArt PAT9125EL is a low-power optical tracking sensor that doesn’t require a lens to work, and a new input driver for it has been added (pixart,pat912x)!
    This sensor is particularly well suited for tracking movement over a shiny/glossy surface. (PR #69492)
Video courtesy of Fabio Baltieri
  • The charger subsystem now allows to define output limits for the discharge rate and the system voltage, allowing to issue alerts when these limits are reached. (PR #67810)
  • The Ethernet driver for the W5500 now supports link status detection. (PR #68752)
  • The ESP-AT Wi-Fi driver now allows to bind and receive from UDP sockets. (PR #68586)

Miscellaneous

  • Various improvements to the DHCPv4 server.
  • New lwm2m_set_bulk() API allows to set multiple resource values at once. (PR #68988)
  • New network shell command (net iface set_ipv4_gateway) allows to set the IPv4 gateway of a network interface. (PR #68465)
  • It is now possible to use CONFIG_SHELL_MSG_CMD_NOT_FOUND and SHELL_MSG_SPECIFY_SUBCOMMAND to indicate what message (if any) will be printed when a given command or subcommand is not found. (PR #69002)
  • New sign_extend() and sign_extend_64() helper functions to perform sign extensions. (PR #68828)
  • Bluetooth CAP Commander now supports the “Change Volume Mute State” procedure. (PR #66281)
  • New POSIX APIs:
    • fattach()
    • fdetach()
    • syslog() (PR #68515)

A big thank you to the 16 individuals who had their first pull request accepted this week, 💙 🙌: @JayHCloud, @bmihelcic, @thompsa, @jaz1-nordic, @vshymanskyy, @rntsoma, @sageve, @jerome-pouiller, @ngphibang, @celinakalus, @MaochenWang1, @allemanm, @Brianmm94, @rysiof, @jpanisbl, and @cmrdrbz.

As always, I very much welcome your thoughts and feedback in the comments below!

If you enjoyed this article, don’t forget to subscribe to this blog to be notified of upcoming publications! And of course, you can also always find me on Twitter and Mastodon.

Catch up on all previous issues of the Zephyr Weekly Update:

Categories
IoT Zephyr

Zephyr Weekly Update – 1 week left before feature freeze

We are entering the last few weeks of the Zephyr 3.6 release cycle, with the feature freeze scheduled for next Friday, February 2. If you have pull requests that are still pending, now might be a good time to make sure they get reviewed and approved to make it in time for 3.6! 🙂

Second round of updates to the Sensing API

PR #64478 has introduced another round of updates to the Sensing API. I haven’t had time to look into all the details so I encourage you to look at the changes directly in the PR.

As a reminder, there is now also a Sensors Working Group that meets every Monday to discuss all things sensors.

Boards & SoCs

  • The SDP-K1 evaluation board from Analog Devices (ADI) is a system demonstration platform (SDP) designed to connect to various evaluation shields containing ADI components. (PR #67278)
  • The STM32WB5MM-DK Discovery Kit is a dev kit for the STM32W5MMG module (dual core Cortex-M4/Cortex-M0+) that comes with an ultra-low-power BLE 5.2 / 802.15.4 radio module, an LCD display, 16MB of external Flash, and a couple of on-board sensors. (PR #67819)
  • All ESP32 boards saw a significant decrease of their minimal heap size thanks to PR #67787.

SoC driver updates

  • Clock initialization has been reworked across all Microchip/Atmel SAM SoCs. (PR #66499)
  • Suspend-to-RAM support has been added for STM32. (PR #67534)
  • New driver for NXP enhanced Direct Memory Access (eDMA). (PR #65671)
  • Driver for Microchip/Atmel SAM flash controller has been redesigned to fully utilize the flash page layout and capabilities of each individual SoC. (PR #64215)

General drivers

  • A new display driver is available for the Galaxy Core GC9A01A display controller, used to drive many round LCD displays these days (at least the ones from AliExpress ^^), like the ones used for smart watches and smart dials. (PR #67012)
  • Bosch BMP581 is a barometric pressure sensor with high accuracy that can be used for e.g. fitness tracking use cases where detecting a change of altitude is required.
    With an average current consumption of 1.3 µA @ 1 Hz, it definitely qualifies as a low-power sensor :). (PR #61535)
  • The driver for BD8LB600FS 8-channel low-side switch now supports daisy-chaining. (PR #65982)
  • New Kconfig options (CONFIG_POWER_DOMAIN_*_INIT_PRIORITY) have been introduced to allow changing the initialization priority of power domains. (PR #67939)
  • A noteworthy breaking API change in the CAN drivers: it is no longer possible to perform run-time filtering of frames based on the Remote Transmission Request bit, and filtering is now instead configured via Kconfig. (PR #67127)

Input drivers

This week’s numerous updates to the input subsystem make for a perfect excuse to shamelessly plug the recent Zephyr Tech Talk with ZMK firmware creator Pete Johanson. Whether you are a mechanical keyboard aficionado or simply curious about hearing how Zephyr was put to good use to enable custom keyboard firmware creation, check it out!

  • Optical encoders are now supported. (PR #66121)
  • A new keymap driver allows to use a Devicetree node to provide the mapping between your keyboard matrix and the actual keys at each row/column intersection. (PR #67757)
kbd {
      ...
      keymap {
          compatible = "input-keymap";
          keymap = <
              MATRIX_KEY(0, 0, INPUT_KEY_1)
              MATRIX_KEY(0, 1, INPUT_KEY_2)
              MATRIX_KEY(0, 2, INPUT_KEY_3)
              MATRIX_KEY(1, 0, INPUT_KEY_4)
              MATRIX_KEY(1, 1, INPUT_KEY_5)
              MATRIX_KEY(1, 2, INPUT_KEY_6)
              MATRIX_KEY(2, 0, INPUT_KEY_7)
              MATRIX_KEY(2, 1, INPUT_KEY_8)
              MATRIX_KEY(2, 2, INPUT_KEY_9)
          >;
          row-size = <3>;
          col-size = <3>;
      };
  };

Miscellaneous

  • Starting with GCC 10, GCC ships with a static analyzer. It is now possible to use Zephyr’s static code analysis infrastructure to easily run GCC static analyzer for your application, simply pass the following parameter when running west build: -DZEPHYR_SCA_VARIANT=gcc. (PR #64595)
  • It is now really easy to build an LLEXT (Linkable Loadable Extension) module thanks to a new add_llext_target() CMake function.
    See the CMakeLists.txt file of the Hello World sample to see how to use it. (PR #67431)
  • New CMake helper function (zephyr_blobs_verify()) allows to verify that blobs fetched using west have a valid checksum. (PR #67593)
  • New APIs allow to check if an IPv6 address is link local or global, see net_ipv6_is_sl_addr() and net_ipv6_is_global_addr(). (PR #67838)
  • A bunch of modules were updated this week:
    • LVGL version has been updated to 8.3.11, with 9.0.0 coming shortly as it’s just been released this week! (PR #66314)
    • zcbor version has been updated to 0.8.0. (PR #67418)
    • LittleFS version has been updated to 2.8.1. (PR #65414)
    • picolibc version has been updated to 1.8.6 (PR #67891)
  • Added support for Wi-Fi STA disconnection. (PR #68007)
  • New POSIX APIs:
    • mq_notify()

A big thank you to the 8 individuals who had their first pull request accepted this week, 💙 🙌: @renpytom, @javad123javad, @itmm, @tanmaykathpalia, @msalau, @73jn, @sandip-dalvi, and @adri1mart1.

As always, I very much welcome your thoughts and feedback in the comments below!

If you enjoyed this article, don’t forget to subscribe to this blog to be notified of upcoming publications! And of course, you can also always find me on Twitter and Mastodon.

Catch up on all previous issues of the Zephyr Weekly Update:

Categories
IoT Zephyr

Zephyr Weekly Update – Trusted Firmware-M 2.0 integration

Happy Friday, and welcome back for another Zephyr Weekly Update. One of the main highlights this week is certainly the recent upgrade to Trusted Firmware-M 2.0.

On the topic of security, I really encourage everyone to watch our latest Zephyr Tech Talk, if you missed the opportunity to watch it live. Kasia Zalewska did an outstanding job of explaining some of the typical security vulnerabilities in embedded software, and what are some of the tools that can help mitigate them. I really loved the live demo part where she demonstrated a buffer overflow attack, as this really made it easier for me to understand how they can be conducted by an attacker, and how software can be hardened to detect/avoid them.

Update to TF-M 2.0

Trusted Firmware provides a reference implementation of secure software for Cortex-A (TF-A) and Cortex-M (TF-M). You can think of it as a toolbox that provides you with all the libraries and code you need to align with Arm’s latest recommendations and specifications regarding security. To quote the trustedfirmware.org website, “this forms the foundations of a Trusted Execution Environment (TEE) on application processors, or the Secure Processing Environment (SPE) of microcontrollers”.

Trusted Firmware-M v2.0.0 was released at the end of last year and one of the main highlights is its smaller memory footprint, in particular thanks to an update to mbedTLS 3.5.0.

As of this week, Zephyr supports TF-M 2.0.0! (PR #66288)

Socket service API

A new socket service has been introduced. It is somewhat similar to Linux’s inetd in that it allows to have only one thread that listens on a set of blocking sockets, and therefore save memory. When there is activity on one of the sockets, the service calls the appropriate callback (servlet? :)) to do the actual work.

A good starting point to learn more is to look at the newly introduced service-based echo server code sample. And of course, more details can also be found in the pull request, PR #66758.

Boards & SoCs

  • The FK7B0M1-VBT6 board by FANKE Technology features an STM32H7B0VBT6 (Cortex-M7) running at up to 280 MHz, 128 KB of Flash (plus 2×8 MB external Flash), and 1.4 MB of SRAM. It can be sourced for about $30 on AliExpress, and is now supported in Zephyr! (PR #65441)
M5Stack AtomS3 Lite
  • I am always really excited to see new hardware from M5Stack supported in Zephyr. This week, it’s the M5Stack AtomS3 Lite 🙂 It’s a device based on an ESP32S3 that’s about the size of a quarter, and that includes just about enough for simple prototyping: a push button, a few pins exposed through an expansion header, and even a mounting hole. (PR #67084)
  • It’s great to see new options for using Bluetooth in Zephyr, this time with the X-NUCLEO-BNRG2A1 shield for STM32 boards. The shield uses a BlueNRG-M2SP application processor module based on the ST BlueNRG-2 System-on-Chip. (PR #67381)

SoC driver updates

  • Voltage control support has been added to the Renesas PFC (pin fonction controller) driver. (PR #66881)
  • New i.MX RGPIO (Rapid GPIO) driver. If you are using the NXP i.MX93 EVK board, it’s already been updated to use this new driver. (PR #62622)

General drivers

  • The NXP DMIC (digital microphone) is a PDM-to-PCM converter intended for use with MEMS microphones. It supports up to 8 channels (or 4 L/R channel pairs) and now has a proper DMIC driver in Zephyr (nxp,dmic compatible). (PR #66448)
  • The existing driver for the PCF8574 8-channel I/O expander has been reworked to now support PCF8575 as well, which is the 16-channel variant (new binding is nxp,pcf857x). (PR #67054)
  • New UART shim for Nordic’s UARTE (UART with EasyDMA) driver. (PR #65155)
  • When using cellular modems, handling of the AT+CESQ AT command for retrieving extending signal quality information has been implemented for U-blox SARA-R5 modem. (PR #67025)

Miscellaneous

  • New DT_IRQ_INTC() and DT_IRQ_INTC_BY_NAME() macros allow to retrieve the interrupt controller associated to a given interrupt specifier Devicetree node. (PR #66707)
  • New kernel APIs added to start and resume a CPU when running in an SMP environment: k_smp_cpu_start() and k_smp_cpu_resume(). (PR #64755)
  • A new net_hostname_set() API allows to set the device hostname at runtime. (PR #67439)
  • It is now possible to do runtime filtering of log messages (it used to be compile-time only) for a log frontend. (PR #67107)
  • New net_buf_data_match() helper function to compare data with the contents of a network buffer. (PR #66757)
  • Added support for SO_DOMAIN socket option. (#67618)
  • New available POSIX APIs:
    • sched_getparam()
    • sched_getscheduler()

A big thank you to the 9 individuals who had their first pull request accepted this week, 💙 🙌: @gzzi, @toonst, @laurin, @VitekST, @amrithvenkat, @shenyi97, @MirkoCovizzi, @mschappa, and @lopsided98.

As always, I very much welcome your thoughts and feedback in the comments below!

If you enjoyed this article, don’t forget to subscribe to this blog to be notified of upcoming publications! And of course, you can also always find me on Twitter and Mastodon.

Catch up on all previous issues of the Zephyr Weekly Update: