Linumiz participated in the OSSummit organized by The Linux Foundation in Dublin, Ireland on Sept 12-16, 2022. Out of 5 talks, 3 talks proposed by Linumiz engineers have been accepted: Dinesh Kumar K  discussed the topic of  — Interfacing Sensor with Zephyr for IoT Devices – Youtube Parthiban  discussed  the topic of  — Contributing to Zephyr vs (Linux…

Screen recording demo for https://sched.co/c3St: This video is in effort for the completeness of the demonstration of talk at OSS about “Software Update (OTA) for Zephyr“. This includes OTA using #mcumgr, #hawkbit, #updatehub for #zephyriot  

    Register now and Join in virtual for Software Update (OTA) for Zephyr from Linumiz and more.   Book your schedule to talk with us: https://calendly.com/linumiz

In previous blog we have used sample key available in MCUboot repository for signing the application image. But it is strictly advised to use custom keys for production purposes or else attacker may modify the application image in flash and take control of the device. In this blog we are going to generate the custom…

In the previous blog post, we have build and flashed the sample application for disco_l475_iot1 board using Zephyr RTOS. In this post we are going to build and flash the same sample application with MCUboot (Bootloader).   What is a MCUboot? Here, MCU stands for Microcontroller and boot stands for bootloader which provides a secure…

Zephyr, a project of The Linux Foundation backed by major tech companies like Intel, Nordic Semiconductor, NXP, Linaro and much more companies developing and maintaining a small real-time operating system for connected, resource constrained devices supporting multiple architectures and targets. Zephyr is released under Open Source Apache License 2.0 This blog is a short tutorial…

uhubctl is utility to control USB power per-port on smart USB hubs. Smart hub is defined as one that implements per-port power switching. This utility can be build in Yocto using the below recipe. View the code on Gist. Above is the bitbake recipe for version 2.0.0. View the code on Gist. Above is the…

After discovering the nearby Bluetooth devices either using StartDiscovery without filter or with SetDiscovertFilter, next big step is to connect with the device and access the functionalities provided by the device. The connection process involves two steps, Pairing – Authenticating and trusting the end bluetooth device Connect itself Here connection can be initiated either by…

BeagleBone Black serial peripheral boot:  BBB supports many peripheral boot options which can be choosen by the SYSBOOT button projected out near p8 header. Button pressed the sequence is spi0 | mmc0 | usb0 | uart0 Button released the sequence is mmc1 | mmc0 | uart0 | usb0 so we have uart0 in both the…

In continuation to our previous blog on bluetooth scanning and remove device after scanning, we will explore on discovery filters. Filters are typically used to narrow down our search. By default “StartDiscovery” will scan for all the nearby bluetooth devices. But in many situations user/developer already knows the desired category of devices. Few examples are,…

In our previous example we have seen method to scan for nearby devices. In this blog we will extend the same example to remove the device explicitly. Code: View the code on Gist. In our previous example while exploring “StartDiscovery” method, we have seen “InterfacesRemoved” signal which will be emitted when any object path or…

So far we have seen ways to get Adapter properties, set the properties and also to list the devices using GetManagedObjects. To get started with real Bluetooth operation in action we need to understand the general use case and methods to achieve it. First thing in communication using Bluetooth is for, Sharing some data (file,…

In this blog we will jump back to use GetManagedObjects method to find the list of Bluetooth devices which are currently present in all the Adapters. This sample in continuation to set property blog will help us understand more about Bluetooth devices and Adapters. Code: View the code on Gist. In this example above we…

In this blog we will continue our understanding toward BlueZ to set the property in Adapter1 interface in continuation to our Get Property sample. As DBUS based applications can be accessed by any number of clients, modification a property needs to be informed to all the clients. In DBUS this can be done using signals.…

In this blog we extent our previous example list HCI controller using GDBUS method to get the properties of the Adapter. We will examine the Adapter properties both by using “GetManagedObject” and also using “GetAll” method in org.freedesktop.DBus.Properties interface. Code: View the code on Gist. In our previous example we have used GetManagedObject and filtered the…

This blog is the continuation of list controllers using HCI interface, to cover the same use case using DBUS interface provided by Bluez. We will be using the “GetManagedObjects” methid to get the list of Bluetooth controllers. Using GDBUS: View the code on Gist. Using GDBUS Proxy: View the code on Gist. If Bluetooth service is…

Yocto stops building the global sysroot (both native and cross) from version 2.6. To build any package yocto copies the sysroot as “recipes-sysroot” and “recipes-sysroot-native” into each WORKDIR. This stops the external application builders from using “tmp/sysroots/<MACHINE>” for cross compilation. To do the same way building external application using common sysroot and toolchain one need…

This is the fist post in the series of blogs for Bluetooth in Linux. In this series we are going to cover mostly about Bluez and it’s provisions for Bluetooth functionality over DBUS (API’s in bluez/doc/). We will also cover few Bluetooth profiles like GAP, A2DP, AVRCP, PBAP in near future. Assumption: This series of…

Source code browsing in large projects is always tedious job to narrow down. In repositories like Linux Kernel, where the source code grows everyday needs regular updating and indexing to keep the search efficient and correct. For browsing the source code in Linux Kernel, there are few options and built-in ways to remember when using…

UART is the traditional serial communication protocol used. It offers only two pins RX and TX for sending and receiving characters serially. A microcontroller can have more than one UART. For instance MSP430F5418 microcontroller has two UART’s (UART and enhanced UART). Just read the desired controller datasheet for getting the info. There are two methods…

It took some time and effort to list the directories alone using ‘ls‘ command. The below option helps in showing that. ls -d */ Here is the working video of  Listing only the directories using ls command

To re-run the previous command, we can use the below special way in bash. !! #This re-runs the previous command But the question is, why should i run ‘!!’ instead of using up arrow for previous command. One quick use case would be for running ‘sudo’. We often end up in ‘Permission denied’ error and…

  We often used to type a lengthy command and realize the error after running the command. To correct this error, either we used to re-type the whole command or edit (after up arrow). This can be easily handled with bash tricks by using ‘^’. Example: cp /some/very/long/path/for/the/source /some/extra/loong/path/for/destination Note the wrong spell ‘loong’ in…

Sometime we may want to run a range of commands which was run in the past (captured in ‘history‘ command). This can be achieved using ‘fc’ command. Run ‘history’ command to find the range you want to re-run. For example, range from 1000 to 1010. fc 1000 1010 The above command will copy the range…