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Memfault State of IoT Report

How to use I2C devices in (Apache) NuttX: Scanning for Devices

Alan C Assis April 22, 2024

Previously in this EmbeddedRelated article, we saw how to use Buttons Subsystem on NuttX using a RaspberryPi Pico board. Now we will change from user input device (buttons) for something more generic: I2C protocol. NuttX supports a lot of I2C devices (sensors, displays, EEPROMs, I/O Expanders, I2C multiplexers, and many more). And most important: because NuttX is a Linux-like RTOS you will find the very familiar i2ctool to search for devices in your I2C bus. So, lets to get...


Using (Apache) NuttX Buttons Subsystem

Alan C Assis March 22, 2024

Previously in this EmbeddedRelated article, we saw how to use LEDs Subsystem on NuttX testing on RaspberryPi Pico. In the same way we avoided using GPIO Subsystem to control LEDs we can avoid using GPIO Subsystem to read Buttons inputs. That is right, NuttX has an Input Device Subsystem like Linux and today we will learn how to use it.

Buttons are one of the simplest user input interface and after the famous "hello world LED" example they are probably the second thing that...


Using (Apache) NuttX USERLED Subsystem

Alan C Assis February 19, 2024

In the previous article (https://embeddedrelated.com/showarticle/1623.php) we saw how to use GPIOs on NuttX testing on RaspberryPi Pico as example. In that article we used the GPIO output to control an LED, but there is a better way to do that. Of course, NuttX has an LED subsystem similar to Linux LED subsystem: it is called USERLED. Today we will see how to control LEDs using NuttX's USERLED subsystem.

The main advantage of using the USERLED subsystem instead of controlling the LEDs...


Using GPIO in (Apache) NuttX RTOS

Alan C Assis January 21, 20243 comments

In the previous article (https://embeddedrelated.com/showarticle/1610.php) we saw how to compile and run NuttX on three low cost boards (RaspberryPi Pico, ESP32-Devkit and STM32F4Discovery). Today we will see how to use GPIO pins and read and write logic level signals from/to the MCU pins.

Everybody knows that blinking a LED is the "Hello World" program of embedded system engineer. Controlling a GPIO we can do exactly that! Although it is important to know that NuttX also has a LED...


Getting Started with NuttX RTOS on Three Low Cost Boards

Alan C Assis November 27, 20235 comments

If you are an embedded system developer chances are you already played with Linux on some embedded board and saw how it is powerful, right?

So, I have a good news: you can have same power using NuttX on some ultra low cost board powered by a microcontroller instead of microprocessor (that normally is way more expansive).

In fact many companies already realized it before me. It explains why NuttX is the kernel used by many IoT frameworks:

Another great news is that few days ago Xiaomi decided to...


Getting Started with (Apache) NuttX RTOS Part 2 - Looking Inside and Creating Your Customized Image

Alan C Assis July 5, 2023

In the previous article (https://www.embeddedrelated.com/showarticle/1524.p...) we saw how to run NuttX RTOS using the SIMulator. Today we will see how NuttX's directory tree is organized and how to use the menuconfig to enable some applications, including some tricks to search and solve dependencies.

NuttX Directories organization:

If you have previously compiled the Linux kernel or the U-Boot bootloader you will see that the NuttX source tree organization is very...


Getting Started with (Apache) NuttX RTOS - Part 1

Alan C Assis June 2, 20234 comments

NuttX RTOS is used in many products from companies like Sony, Xiaomi, Samsung, Google/Fitbit, WildernessLabs and many other companis. So, probably you are already using NuttX even without knowing it, like the you was using Linux on your TV, WiFi router more than 10 years ago and didn't know too! Today you will have the chance to discover a little bit of this fantastic Linux-like RTOS! Are you ready? So, let's get started!


How to use I2C devices in (Apache) NuttX: Scanning for Devices

Alan C Assis April 22, 2024

Previously in this EmbeddedRelated article, we saw how to use Buttons Subsystem on NuttX using a RaspberryPi Pico board. Now we will change from user input device (buttons) for something more generic: I2C protocol. NuttX supports a lot of I2C devices (sensors, displays, EEPROMs, I/O Expanders, I2C multiplexers, and many more). And most important: because NuttX is a Linux-like RTOS you will find the very familiar i2ctool to search for devices in your I2C bus. So, lets to get...


Getting Started with (Apache) NuttX RTOS - Part 1

Alan C Assis June 2, 20234 comments

NuttX RTOS is used in many products from companies like Sony, Xiaomi, Samsung, Google/Fitbit, WildernessLabs and many other companis. So, probably you are already using NuttX even without knowing it, like the you was using Linux on your TV, WiFi router more than 10 years ago and didn't know too! Today you will have the chance to discover a little bit of this fantastic Linux-like RTOS! Are you ready? So, let's get started!


Getting Started with NuttX RTOS on Three Low Cost Boards

Alan C Assis November 27, 20235 comments

If you are an embedded system developer chances are you already played with Linux on some embedded board and saw how it is powerful, right?

So, I have a good news: you can have same power using NuttX on some ultra low cost board powered by a microcontroller instead of microprocessor (that normally is way more expansive).

In fact many companies already realized it before me. It explains why NuttX is the kernel used by many IoT frameworks:

Another great news is that few days ago Xiaomi decided to...


Getting Started with (Apache) NuttX RTOS Part 2 - Looking Inside and Creating Your Customized Image

Alan C Assis July 5, 2023

In the previous article (https://www.embeddedrelated.com/showarticle/1524.p...) we saw how to run NuttX RTOS using the SIMulator. Today we will see how NuttX's directory tree is organized and how to use the menuconfig to enable some applications, including some tricks to search and solve dependencies.

NuttX Directories organization:

If you have previously compiled the Linux kernel or the U-Boot bootloader you will see that the NuttX source tree organization is very...


Using GPIO in (Apache) NuttX RTOS

Alan C Assis January 21, 20243 comments

In the previous article (https://embeddedrelated.com/showarticle/1610.php) we saw how to compile and run NuttX on three low cost boards (RaspberryPi Pico, ESP32-Devkit and STM32F4Discovery). Today we will see how to use GPIO pins and read and write logic level signals from/to the MCU pins.

Everybody knows that blinking a LED is the "Hello World" program of embedded system engineer. Controlling a GPIO we can do exactly that! Although it is important to know that NuttX also has a LED...


Using (Apache) NuttX Buttons Subsystem

Alan C Assis March 22, 2024

Previously in this EmbeddedRelated article, we saw how to use LEDs Subsystem on NuttX testing on RaspberryPi Pico. In the same way we avoided using GPIO Subsystem to control LEDs we can avoid using GPIO Subsystem to read Buttons inputs. That is right, NuttX has an Input Device Subsystem like Linux and today we will learn how to use it.

Buttons are one of the simplest user input interface and after the famous "hello world LED" example they are probably the second thing that...


Using (Apache) NuttX USERLED Subsystem

Alan C Assis February 19, 2024

In the previous article (https://embeddedrelated.com/showarticle/1623.php) we saw how to use GPIOs on NuttX testing on RaspberryPi Pico as example. In that article we used the GPIO output to control an LED, but there is a better way to do that. Of course, NuttX has an LED subsystem similar to Linux LED subsystem: it is called USERLED. Today we will see how to control LEDs using NuttX's USERLED subsystem.

The main advantage of using the USERLED subsystem instead of controlling the LEDs...


Memfault State of IoT Report