Cutting Through the Confusion with ARM Cortex-M Interrupt Priorities

Miro Samek February 26, 2016

The insanely popular ARM Cortex-M processor offers very versatile interrupt priority management, but unfortunately, the multiple priority numbering conventions used in managing the interrupt priorities are often counter-intuitive, inconsistent, and confusing, which can lead to bugs. In this post I attempt to explain the subject and cut through the confusion.

The Inverse Relationship Between Priority Numbers and Urgency of the Interrupts

The most important fact to know is that ARM...


Introduction to Microcontrollers - Ada - 7 Segments and Catching Errors

Mike Silva September 22, 20145 comments

7 Segments the Ada Way

Here is the Ada version (I should say AN Ada version) of the 7 segment multiplexing code presented in the last installment.  The hardware now is the STM32F407 Discover board, which is a Cortex M4F board.  There are lots of differences in GPIO and timer setup, but if you understoold the previous code in C you should not have much trouble understanding this code in Ada.

As interesting as the Ada approach to the task is the Ada ability to detect...


Introduction to Microcontrollers - 7-segment displays & Multiplexing

Mike Silva August 14, 2014

Doing the 7 Segment Shuffle

The 7 segment display is ubiquitous in the modern world.  Just about every digital clock, calculator and movie bomb has one.  The treadmills at my gym have 6 or 7, each one displaying 3 or 4 digits.  What makes the 7-seg interesting is that it presents an opportunity to make a trade off between GPIO (output pins) for time.  Every 7-seg display requires 8 outputs (the 7 segments and usually either a decimal point or a...


Using the Beaglebone PRU to achieve realtime at low cost

Fabien Le Mentec April 25, 20148 comments
Introduction

I work as an engineer in a synchrotron facility. A few weeks ago, I helped the people in charge of the power supply developments to integrate a realtime control algorithm on a prototype platform: a BeagleBone Black (BBB) running Linux. I had already worked with this board in the past, and I found it very interesting given its excellent resources versus price ratio (around 40 euros). This time, I was impressed by its realtime capabilities. I thought it would be a good idea to...


Embedded Systems - free EdX course by UT-Austin!

Lonnie Honeycutt October 29, 20131 comment

I was very excited to see that there will be an Embedded Systems class available for free at https://www.edx.org/course/utaustin/ut-6-01x/embedded-systems-shape-world/1172

It's free to sign up and take the online class at the EdX website.

More exciting is that the class is based on a TI Launchpad Tiva microcontroller development board.  The Tiva Launchpad features an 80-MHz ARM Cortex M-4 MCU with 256 KB of flash storage, 32 KB of RAM and 43 general purpose I/O pins.  


How to install Ubuntu 12.04 Precise, Xubuntu-desktop and Open JDK-7 on Beagleboard Rev. C2

Dr. Tayyar GUZEL July 25, 20124 comments

My aim was to install Ubuntu 12.04, Xubuntu-desktop graphical user interface and Java virtual machine (Open JDK-7) on my beagleboard so that I could run my java application on the monitor connected to the BB. I encountered several problems and solved them one by one. Following is how I've done it..

I had all the accesorries for the beagleboard (usb hub, dvi-to-hdmi cable, usb-ethernet converter, usb keyboard, usb mouse and a hdmi enabled monitor).

My host PC also has a Ubuntu 12.04...


Welcome to my life!

Morten Dramstad July 18, 20127 comments

Hi folks!

As an electronic engineer the most of my work is about making new designs where a microcontroller is present in 99.9 % of the applications. Since 2003 I am self-employed and do consultants work for different companies. I have been traveling to different parts of the world doing work for DeLaval International, a company that makes automation equipment for the dairy industry. A lot of the things I have done for them involves use of different Atmel AVR...


Boot sequence for an ARM based embedded system -2

DM April 6, 201213 comments

In the last post, we discussed about the startup execution sequence on an ARM based embedded system in broader terms. In this post, we are going to cover the details of a startup code.These details are also available through various ARM resources , however for the sake of completion of our discussion , here is - the flow the startup code for an  ARM based embedded system.

 Step 1: The reset

On startup, the processor will jump to fixed location ,(most ARM cores support two vector...


Boot Sequence for an ARM based embedded system

DM January 16, 201230 comments

Hello all,

Allow me to introduce myself. I am Deeksha and I come from plains of North India. My tryst with embedded technologies has been 5 years long and every single day I am amazed with the vastness and learning involved. The thing with embedded technologies is either you are into it, or you aren't. You cannot just hang around half-heartedly (I guess that holds true for every field, for that matter).You have to keep the learning and sharing process going on. And that is the reason I am...


C++ on microcontrollers 4 – input pins, and decoding a rotary switch

Wouter van Ooijen November 12, 20112 comments

previous parts: 1, 2, 3

 This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

So far I...


Using the Beaglebone PRU to achieve realtime at low cost

Fabien Le Mentec April 25, 20148 comments
Introduction

I work as an engineer in a synchrotron facility. A few weeks ago, I helped the people in charge of the power supply developments to integrate a realtime control algorithm on a prototype platform: a BeagleBone Black (BBB) running Linux. I had already worked with this board in the past, and I found it very interesting given its excellent resources versus price ratio (around 40 euros). This time, I was impressed by its realtime capabilities. I thought it would be a good idea to...


Boot Sequence for an ARM based embedded system

DM January 16, 201230 comments

Hello all,

Allow me to introduce myself. I am Deeksha and I come from plains of North India. My tryst with embedded technologies has been 5 years long and every single day I am amazed with the vastness and learning involved. The thing with embedded technologies is either you are into it, or you aren't. You cannot just hang around half-heartedly (I guess that holds true for every field, for that matter).You have to keep the learning and sharing process going on. And that is the reason I am...


An overview of Linux Boot Process for Embedded Systems

Kunal Singh December 25, 200811 comments

This Text provides an insight in to the Embedded Linux Boot Process. Reader should have a basic Knowledge of Boot Process in general and should be familiar with Embedded Linux Boot Process.

.................PART-A................(1) Software components Involved in Embedded Linux Boot Process    (a) Bootloader    (b) kernel Image    (c) root file system - either an initrd image or a NFS location(2) Steps during Booting process of a conventional...

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

Wouter van Ooijen October 9, 20118 comments

 

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

I am lazy. I am also a programmer. Luckily, being a lazy...


Boot sequence for an ARM based embedded system -2

DM April 6, 201213 comments

In the last post, we discussed about the startup execution sequence on an ARM based embedded system in broader terms. In this post, we are going to cover the details of a startup code.These details are also available through various ARM resources , however for the sake of completion of our discussion , here is - the flow the startup code for an  ARM based embedded system.

 Step 1: The reset

On startup, the processor will jump to fixed location ,(most ARM cores support two vector...


Introduction to Microcontrollers - 7-segment displays & Multiplexing

Mike Silva August 14, 2014

Doing the 7 Segment Shuffle

The 7 segment display is ubiquitous in the modern world.  Just about every digital clock, calculator and movie bomb has one.  The treadmills at my gym have 6 or 7, each one displaying 3 or 4 digits.  What makes the 7-seg interesting is that it presents an opportunity to make a trade off between GPIO (output pins) for time.  Every 7-seg display requires 8 outputs (the 7 segments and usually either a decimal point or a...


C++ on microcontrollers 2 - LPCXpresso, LPC-link, Code Sourcery, lpc21isp, linkerscript, LPC1114 startup

Wouter van Ooijen October 24, 20114 comments

 previous parts: 1

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

I teach my students that...


Introduction to Microcontrollers - Ada - 7 Segments and Catching Errors

Mike Silva September 22, 20145 comments

7 Segments the Ada Way

Here is the Ada version (I should say AN Ada version) of the 7 segment multiplexing code presented in the last installment.  The hardware now is the STM32F407 Discover board, which is a Cortex M4F board.  There are lots of differences in GPIO and timer setup, but if you understoold the previous code in C you should not have much trouble understanding this code in Ada.

As interesting as the Ada approach to the task is the Ada ability to detect...


How to install Ubuntu 12.04 Precise, Xubuntu-desktop and Open JDK-7 on Beagleboard Rev. C2

Dr. Tayyar GUZEL July 25, 20124 comments

My aim was to install Ubuntu 12.04, Xubuntu-desktop graphical user interface and Java virtual machine (Open JDK-7) on my beagleboard so that I could run my java application on the monitor connected to the BB. I encountered several problems and solved them one by one. Following is how I've done it..

I had all the accesorries for the beagleboard (usb hub, dvi-to-hdmi cable, usb-ethernet converter, usb keyboard, usb mouse and a hdmi enabled monitor).

My host PC also has a Ubuntu 12.04...


C++ on microcontrollers 4 – input pins, and decoding a rotary switch

Wouter van Ooijen November 12, 20112 comments

previous parts: 1, 2, 3

 This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

So far I...