Favorite Tools: C++11 User-defined literals
In many software domains units of measurement are frequently critical to the software's data processing requirements. Those same units, or rather the use of the wrong units, are often the source of bugs and disastrous mistakes. Although...
Experiences with the Linux Real Time Scheduler
●1 commentI have recently been helping with embedded software design and development for a data acquisition and visualization device. The software executes within an embedded Linux context and consists of various animated user interfaces rendering the...
Favorite Tools - Look Up Tables
●1 commentAs we grow in our engineering careers, we must continually add new tools to our collective tool kits. One favorite tool in my toolkit will be obvious to many experienced embedded software engineers. I still remember learning this approach early...
From bare-metal to RTOS: 5 Reasons to use an RTOS
●1 commentDevelopers can come up with amazing and convoluted reasons to not use an RTOS. I have heard excuses ranging from they are too expensive (despite open source solutions) all the way to they aren’t efficient and use too much memory. In some...
NXP LPC17xx/40xx: Decoding the Part ID
This is the first blog of a number dealing with the NXP LPC17xx/40xx processor families and how to program them despite the lack of documentation. The next blog will deal with implementing the LPC17xx/40xx UART with interrupts...
Use DPLL to Lock Digital Oscillator to 1PPS Signal
Introduction There are occasions where it is desirable to lock a digital oscillator to an external time reference such as the 1PPS (One Pulse Per Second) signal output from a GPS receiver. One approach would be to synchronize a fixed frequency...
The habitat of hardware bugs
The Moscow apartment which little me called home was also home to many other creatures, from smallish cockroaches to biggish rats. But of course we rarely met them face to face. Evolution has weeded out those animals imprudent...
Digital PLL's -- Part 2
In Part 1, we found the time response of a 2nd order PLL with a proportional + integral (lead-lag) loop filter. Now let’s look at this PLL in the Z-domain [1, 2]. We will find that the response is characterized by a loop natural...
From Baremetal to RTOS: A review of scheduling techniques
●5 commentsTransitioning from bare-metal embedded software development to a real-time operating system (RTOS) can be a difficult endeavor. Many developers struggle with the question of whether they should use an RTOS or simply use a bare-metal scheduler....
Choosing a Microcontroller for Your Vehicle
There are many things to take into consideration when choosing a microcontroller or microprocessor for your autonomous vehicle.VoltageSome processors run on 5V and others use 3.3V. Be sure to check the documentation before you buy. ...
MSP430 LaunchPad Tutorial - Part 4 - UART Transmission
●3 commentsToday we are going to learn how to communicate using UART with the Launchpad. For this purpose I will replace the default microcontroller that comes with the board with the MSP430G2553. It is the most powerful device in the MSP430 Value Line and...
Boot Sequence for an ARM based embedded system
●6 commentsHello 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...
MSP430 Launchpad Tutorial - Part 1 - Basics
●4 commentsTI's LaunchPad is a complete MSP430 development environment: all you have to do is download and install CCS IDE (login required), connect your G2231-ready LaunchPad to your computer with the included mini-usb cable, and you are ready to...
How FPGAs work, and why you'll buy one
●2 commentsToday, pretty much everyone has a CPU, a DSP and a GPU, buried somewhere in their PC, phone, car, etc. Most don't know or care that they bought any of these, but they did. Will everyone, at some future point, also buy an FPGA? The market size...
Introduction to Microcontrollers - Interrupts
●1 comment[quicklinks] It's Too Soon To Talk About Interrupts! That, at least, could be one reaction to this chapter. But over the years I've become convinced that new microcontroller programmers should understand interrupts before being...
MSP430 LaunchPad Tutorial - Part 3 - ADC
●2 commentsIn this new episode of our journey into MSP430 I will explain the basics of Analog to Digital Conversion on the MSP430G2231.We will write a program that will read an ADC channel and will toggle some leds based on the result of the...
Introduction to Microcontrollers - Timers
●2 comments[quicklinks] Timers - Because "When" Matters Computer programs are odd things, for one reason because they have no concept of time. They may have the concept of sequential execution, but the time between instructions can be...
How to Build a Fixed-Point PI Controller That Just Works: Part I
●4 commentsThis two-part article explains five tips to make a fixed-point PI controller work well. I am not going to talk about loop tuning -- there are hundreds of articles and books about that; any control-systems course will go over loop tuning enough to...
How to Estimate Encoder Velocity Without Making Stupid Mistakes: Part I
●3 commentsHere's a common problem: you have a quadrature encoder to measure the angular position of a motor, and you want to know both the position and the velocity. How do you do it? Some people do it poorly -- this article is how not to be one of...
Lost Secrets of the H-Bridge, Part III: Practical Issues of Inductor and Capacitor Ripple Current
●4 commentsWe've been analyzing the ripple current in an H-bridge, both in an inductive load and the DC link capacitor. Here's a really quick recap; if you want to get into more details, go back and read part I and part II until you've got equations coming...
