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. ...
Digital PLL's -- Part 1
1. Introduction Figure 1.1 is a block diagram of a digital PLL (DPLL). The purpose of the DPLL is to lock the phase of a numerically controlled oscillator (NCO) to a reference signal. The loop includes a phase detector to compute ...
Best Firmware Architecture Attributes
●1 commentArchitecture of a firmware (FW) in a way defines the life-cycle of your product. Often companies start with a simple-version of a product as a response to the time-to-market caveat of the business, make some cash out...
A few uses for an autonomous vehicle
From the time technology that we have come to know was invented, it has been used to gain an advantage militarily or to make life easier. Military usage seems to be a driving factor, but it is not the only factor. Guerilla tactics played...
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....
So You Want To Be An Embedded Systems Developer
Then listen now to what I say. Just get an electric guitar and take some time and learn how to play. Oh, wait, that's a song by the Byrds. But the strategy is the same. Get some information and tools and learn how to use them. No need to...
Ten Little Algorithms, Part 5: Quadratic Extremum Interpolation and Chandrupatla's Method
Today we will be drifting back into the topic of numerical methods, and look at an algorithm that takes in a series of discretely-sampled data points, and estimates the maximum value of the waveform they were sampled from.
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...
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...
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...
Endianness and Serial Communication
●1 commentEndianness is a consideration that is easily overlooked in the design of embedded systems. I myself am amply guilty of this oversight. It’s something you don’t ever have to worry about if you’re only working with a single...
Byte and Switch (Part 1)
●1 commentImagine for a minute you have an electromagnet, and a microcontroller, and you want to use the microcontroller to turn the electromagnet on and off. Sounds pretty typical, right?We ask this question on our interviews of entry-level electrical...
Boot sequence for an ARM based embedded system -2
●3 commentsIn 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...
Introduction to Microcontrollers - Further Beginnings
●3 commentsEmbedded Programming Basics This tutorial entry will discuss some further embedded programming basics that you will need to understand before proceeding on to the LED blinky and other example programs. We will do this by looking at the...
