EmbeddedRelated.com

ANCS and HID: Controlling Your iPhone From Zephyr

Mohammed Billoo June 11, 2024

In this blog post, we see how certain BLE services can be used to control an iPhone from a Nordic nRF52840 using The Zephyr Project. Specifically, we see how to control certain multimedia functionality using the HID service. Finally, we learn how to use the ANCS client library provided by Nordic in The Zephyr Project to accept or decline an incoming call.


Getting Started With CUDA C on an Nvidia Jetson: A Meaningful Algorithm

Mohammed Billoo May 11, 2024

In this blog post, I demonstrate a use case and corresponding GPU implementation where meaningful performance gains are realized and observed. Specifically, I implement a "blurring" algorithm on a large 1000x1000 pixel image. I show that the GPU-based implementation is 1000x faster than the CPU-based implementation.


Getting Started With CUDA C on an Nvidia Jetson: GPU Architecture

Mohammed Billoo March 28, 2024

In the previous blog post (Getting Started With CUDA C on Jetson Nvidia: Hello CUDA World!) I showed how to develop applications targeted at a GPU on a Nvidia Jetson Nano. As we observed in that blog post, performing a calculation on a 1-D array on a GPU had no performance benefit compared to a traditional CPU implementation, even on an array with many elements. In this blog post, we will learn about the GPU architecture to better explain the behavior and to understand the applications where a GPU shines (hint: it has to do with graphics).


Getting Started With CUDA C on an Nvidia Jetson: Hello CUDA World!

Mohammed Billoo March 13, 2024

In this blog post, I introduce CUDA, which is a framework designed to allow developers to take advantage of Nvidia's GPU hardware acceleration to efficiently implement certain type of applications. I demonstrate an implementation to perform vector addition using CUDA C and compare it against the traditional implementation in "regular" C.


Getting Started With Zephyr: Bluetooth Low Energy

Mohammed Billoo January 29, 2024

In this blog post, I show how to enable BLE support in a Zephyr application. First, I show the necessary configuration options in Kconfig. Then, I show how to use the Zephyr functions and macros to create a custom service and characteristic for a contrived application.


Getting Started With Zephyr: Writing Data to EEPROM

Mohammed Billoo December 6, 20235 comments

In this blog post, I show how to implement a Zephyr application to interact with EEPROM. I show how the Zephyr device driver model allows application writers to be free of the underlying implementation details. Unfortunately, the application didn't work as expected, and I'm still troubleshooting the cause.


Getting Started With Zephyr: Saving Data To Files

Mohammed Billoo October 31, 2023

In this blog post, I show how to implement a Zephyr application to mount a microSD card, create a new file on the microSD card, and write data to it. The lessons learned from such an application can be helpful for devices out in the field that need to write data to off-board memory periodically, especially in cases where Internet access may be sporadic.


Getting Started With Zephyr: Devicetree Overlays

Mohammed Billoo September 25, 2023

In this blog post, I show how the Devicetree overlay is a valuable construct in The Zephyr Project RTOS. Overlays allow embedded software engineers to override the default pin configuration specified in Zephyr for a particular board. In this blog post, I use I2C as an example. Specifically, I showed the default I2C pins used for the nRF52840 development kit in the nominal Zephyr Devicetree. Then, I demonstrated how an overlay can be used to override this pin configuration and the final result.


Getting Started With Zephyr: Devicetree Bindings

Mohammed Billoo August 16, 2023

This blog post shines some light on how devicetrees are used in The Zephyr Project. Specifically, we understand the mechanisms that enable us to use nodes in the devicetree in the C source files. We use a sample provided in the Zephyr repository itself and work our way through portions of the Zephyr codebase to get insight into the mechanisms that make this possible.


Getting Started With Zephyr: Devicetrees

Mohammed Billoo July 18, 20232 comments

This blog post provides an introduction to the "Devicetree", another unique concept in The Zephyr Project. We learn about the basic syntax of a device tree and how its structure and hierarchy mirror hardware, from the SoC to the final board. We also see how hardware described in a devicetree can be referenced and controlled in the source code of a Zephyr-based application.


Libgpiod - Toggling GPIOs The Right Way In Embedded Linux

Mohammed Billoo January 24, 2023
Overview

We all know that GPIO is one of the core elements of any embedded system. We use GPIOs to control LEDs and use them to monitor switches and button presses. In modern embedded systems, GPIOs can also be used as pins for other peripheral busses, such as SPI and I2C. Similar to the previous article on interacting with peripherals on an SPI bus in userspace via SPIdev (https://www.embeddedrelated.com/showarticle/1485.php), we can also control GPIOs from userspace on an embedded...


Getting Started With Zephyr: West Manifest Customization

Mohammed Billoo April 4, 2023
Introduction

The Zephyr Project RTOS (https://zephyrproject.org/), or simply “Zephyr” as it is known colloquially, is an increasingly popular real-time operating system due to its native support for over 450 boards and countless peripherals. When starting with any embedded software project, the first task is to start from a known baseline. This can include cloning a repository from source control, which can be the case with embedded Linux, or downloading a zip file representing a...


Getting Started With Embedded Linux - From Nothing To A Login Prompt

Mohammed Billoo September 28, 2022

One of the famous observations that have been made related to embedded systems is referred to as “Moore’s Law”, which states that the number of transistors in integrated circuits doubles every year. This observation has held mostly true for the past several decades, so powerful CPUs are no longer simply relegated to servers, desktops, and laptops. Instead, we see powerful CPUs with increased capabilities being introduced into embedded systems on devices that live at “the edge”....


Getting Started With Zephyr: Kconfig

Mohammed Billoo June 22, 2023

In this blog post, we briefly look at Kconfig, one of the core pieces of the Zephyr infrastructure. Kconfig allows embedded software developers to turn specific subsystems on or off within Zephyr efficiently and control their behavior. We also learn how we can practically use Kconfig to control the features of our application using the two most common mechanisms.


Getting Started With Zephyr: Devicetree Overlays

Mohammed Billoo September 25, 2023

In this blog post, I show how the Devicetree overlay is a valuable construct in The Zephyr Project RTOS. Overlays allow embedded software engineers to override the default pin configuration specified in Zephyr for a particular board. In this blog post, I use I2C as an example. Specifically, I showed the default I2C pins used for the nRF52840 development kit in the nominal Zephyr Devicetree. Then, I demonstrated how an overlay can be used to override this pin configuration and the final result.


Getting Started With Zephyr: Devicetrees

Mohammed Billoo July 18, 20232 comments

This blog post provides an introduction to the "Devicetree", another unique concept in The Zephyr Project. We learn about the basic syntax of a device tree and how its structure and hierarchy mirror hardware, from the SoC to the final board. We also see how hardware described in a devicetree can be referenced and controlled in the source code of a Zephyr-based application.


Getting Started With Zephyr: Writing Data to EEPROM

Mohammed Billoo December 6, 20235 comments

In this blog post, I show how to implement a Zephyr application to interact with EEPROM. I show how the Zephyr device driver model allows application writers to be free of the underlying implementation details. Unfortunately, the application didn't work as expected, and I'm still troubleshooting the cause.


Peripheral Interaction Without a Linux Device Driver Using Spidev

Mohammed Billoo November 20, 2022
Overview

When integrating a new peripheral onto an embedded Linux platform, we might think we always need to implement a kernel module to serve as a device driver. However, as we all know, absolutes such as “always” and “never” are rarely true. The same is true in this case. Implementing a device driver in kernel space on an embedded Linux platform should only be undertaken if the performance requirements of the final application demand it. In most instances, a userspace...


Getting Started With Zephyr: Saving Data To Files

Mohammed Billoo October 31, 2023

In this blog post, I show how to implement a Zephyr application to mount a microSD card, create a new file on the microSD card, and write data to it. The lessons learned from such an application can be helpful for devices out in the field that need to write data to off-board memory periodically, especially in cases where Internet access may be sporadic.


Getting Started With Zephyr: Devicetree Bindings

Mohammed Billoo August 16, 2023

This blog post shines some light on how devicetrees are used in The Zephyr Project. Specifically, we understand the mechanisms that enable us to use nodes in the devicetree in the C source files. We use a sample provided in the Zephyr repository itself and work our way through portions of the Zephyr codebase to get insight into the mechanisms that make this possible.