EmbeddedRelated.com

Memory Mapped I/O in C

Mattia MaldiniMattia Maldini July 25, 20248 comments

Interacting with memory mapped device registers is at the base of all embedded development. Let's explore what tools the C language - standard of the industry - provide the developer with to face this task.


How to use SPI devices in NuttX RTOS

Alan C AssisAlan C Assis June 30, 2024

You can get an SPI sensor running on NuttX in minutes by following a concrete RP2040 example. This post walks through the board glue code, Makefile and header edits, menuconfig settings, wiring, and flash steps needed to register a MAX6675 thermocouple on a Raspberry Pi Pico. Read it to learn where to add board-level code, enable drivers, and test the device from NSH.


7 Essential Steps for Reducing Power Consumption in Embedded Devices

Jacob BeningoJacob Beningo June 26, 20241 comment

Reducing the amount of power your embedded device is consuming is not trivial. With so many devices moving to battery operations today, maximizing battery life can be the difference between a happy, raving customer and an unhappy one that ruins your company's reputation. This post explores seven steps for optimizing your embedded systems' power consumption. You'll gain insights into the steps and techniques necessary along with receiving a few resources to help you on your journey.


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

Mohammed BillooMohammed 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.


Introduction to PIC Timers

Luther StantonLuther Stanton May 8, 2024

The fourth in a series of five posts looks at 8-bit PIC hardware timers. After a review of basic timer functionality, the Timer0 module operation and configuration is reviewed and a basic application implemented using Timer0 to blink external LEDs at a frequency of 0.5Hz.


You Don't Need an RTOS (Part 2)

Nathan JonesNathan Jones May 7, 20247 comments

In this second article, we'll tweak the simple superloop in three critical ways that will improve it's worst-case response time (WCRT) to be nearly as good as a preemptive RTOS ("real-time operating system"). We'll do this by adding task priorities, interrupts, and finite state machines. Additionally, we'll discuss how to incorporate a sleep mode when there's no work to be done and I'll also share with you a different variation on the superloop that can help schedule even the toughest of task sets.


Working with Microchip PIC 8-bit GPIO

Luther StantonLuther Stanton April 24, 20241 comment

The third in a series of five posts looks at GPIO with PIC 8-bit microcontrollers. After a detailed review of the registers for configuring and managing GPIO on the PIC18F47Q10 processor, a basic application is stood up programming those registers to blink external LEDs at 0.5Hz.


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

Alan C AssisAlan C Assis April 22, 2024

Hands-on guide to scanning I2C peripherals on NuttX using a Raspberry Pi Pico, showing how the RTOS exposes i2c master instances and the i2ctool. The article walks through where the RP2040 I2C driver lives, how to enable I2C0 in menuconfig, build and flash nuttx, and run the i2c dev command to probe the bus. Verify sensors like BMP280 or SSD1306 before registering drivers.


Blinkenlights 2.0

Ido GendelIdo Gendel April 17, 2024

Nothing spells old movie computers like a panel of randomly blinking lights, but in fact, these so-called "blinkenlights" can be valuable indicators - especially in embedded systems where the user interface must be minimal, small and cheap. Control of these lights can be achieved using a very simple, real-time interpreted script, and this kind of solution may be extended to other and more complex embedded tasks.


When a Mongoose met a MicroPython, part I

Sergio R CaprileSergio R Caprile March 31, 2024

This is more a framework than an actual application, with it you can integrate MicroPython and Cesanta's Mongoose.
Mongoose runs when called by MicroPython and is able to run Python functions as callbacks for the events you decide in your event handler. The code is completely written in C, except for the example Python callback functions, of course. To try it, you can just build this example on a Linux machine, and, with just a small tweak, you can also run it on any ESP32 board.


Boot Sequence for an ARM based embedded system

 DM DM January 16, 201231 comments

Deeksha draws on five years in embedded systems to introduce the ARM boot sequence used on Boot ROM based platforms. The post outlines what the Boot ROM does at reset, how it probes boot media, and when control is passed to a software bootloader. It also highlights key differences between NOR XiP and NAND RAM-loading and the need for bad-block handling.


MSP430 LaunchPad Tutorial - Part 3 - ADC

Enrico GaranteEnrico Garante June 25, 20138 comments

Enrico Garante walks through practical ADC use on the MSP430G2231, from a single-channel read that toggles LaunchPad LEDs to multi-channel repeated conversions. The post includes complete code, an ADC10 interrupt example to wake from low-power mode, and a DTC-backed array transfer so you can collect samples without polling. A short CCS debugging tip shows how to watch ADC variables while running.


Analog-to-Digital Confusion: Pitfalls of Driving an ADC

Jason SachsJason Sachs November 19, 20118 comments

Wayne's thermistor board showed one ADC channel changing when another was heated, a classic case of ADC input cross-coupling. The post walks through how multiplexed ADCs, the small sample-and-hold capacitor, source impedance, sampling time, repeated sampling rates, and added charge reservoirs interact to create errors. Learn practical fixes including increasing sample time, sizing external caps, adding op-amp buffers, and using an RC dampener with PCB layout tips.


Introduction to Microcontrollers - Hello World

Mike SilvaMike Silva September 11, 201316 comments

Mike Silva walks through the classic embedded hello world by blinking an LED on both an AVR and an STM32. The tutorial covers GPIO configuration, bit manipulation, simple software delay loops, and common pitfalls such as compiler optimizations that can remove empty delays unless you use volatile. Practical wiring tips and debugging advice with a scope make this an ideal first lab for embedded engineers.


Using the C language to program the am335x PRU

Fabien Le MentecFabien Le Mentec June 7, 201481 comments

Assembly-language PRU development is tedious and error prone, so Fabien Le Mentec shows how to use TI's PRU C toolchain to simplify the workflow. He walks through installing the CGT package, integrating the compiler with a modified prussdrv loader to honor the _c_int00 start symbol, and provides a BeagleBone Black example with build scripts and sources on GitHub. The post also covers inline assembly constraints and code-size tradeoffs.


C++ on microcontrollers 1 - introduction, and an output pin class

Wouter van OoijenWouter van Ooijen October 9, 20117 comments

Wouter van Ooijen shows how small C++ abstractions make GPIO code portable and reusable. Starting from a simple output_pin interface he implements concrete pins for an LPC2148 GPIO and a 74HC595 shift register, then composes behaviors with wrappers like tee and invert. The post demonstrates virtual methods, references, and constructor initialization lists to build drivers you can reuse across boards.


Byte and Switch (Part 1)

Jason SachsJason Sachs April 26, 201114 comments

Driving a 24V electromagnet from a 3.3V microcontroller looks trivial, but Jason Sachs shows how that simple switch can fail spectacularly. He walks through the cause of MOSFET destruction when an inductive load is turned off, and explains the practical fixes you actually need: a flyback diode, a gate series resistor, and a gate pulldown to keep the transistor well behaved.


Introduction to Microcontrollers - Timers

Mike SilvaMike Silva September 27, 20132 comments

Time is everything in embedded systems, and Mike Silva walks through how microcontroller timers turn clock pulses into dependable events. He covers prescalers, counter bit widths, overflow versus compare modes, atomic multi-byte register access, the "-1 rule", input capture and compare leapfrogging, with concrete AVR and STM32 code that highlights common pitfalls and reliable patterns for precise ticks.


An overview of Linux Boot Process for Embedded Systems

Kunal SinghKunal Singh December 25, 200811 comments

Booting Linux on embedded hardware collapses PC boot stages into a single bootloader, and understanding the early steps helps troubleshoot low-level failures. Kunal Singh breaks down the sequence from the bootstrap firmware and primary/secondary bootloaders through zImage decompression, MMU and page table setup, start_kernel, and the initrd pivot to the root filesystem. Practical focus favors ARM examples.


Boot sequence for an ARM based embedded system -2

 DM DM April 6, 201213 comments

DM walks through the concrete steps of an ARM system startup, from the reset vector to handing control to C. The post explains what the early assembly reset code must do: set system registers, initialize stacks, set up the MMU, copy .data and clear .bss, and remap the vector table into RAM for faster interrupts. It finishes with external memory bring-up and loading an OS image.