EmbeddedRelated.com
Tutorials

Thermistor signal conditioning: Dos and Don'ts, Tips and Tricks

Jason Sachs June 15, 201118 comments

In an earlier blog entry,  I mentioned this circuit for thermistor signal conditioning:

It is worth a little more explanation on thermistor signal conditioning; it's something that's often done poorly, whereas it's among the easiest applications for signal conditioning.

The basic premise here is that there are two resistors in a voltage divider: Rth is the thermistor, and Rref is a reference resistor. Here Rref is either R3 alone, or R3 || R4, depending on the gain...


Real-time clocks: Does anybody really know what time it is?

Jason Sachs May 29, 20118 comments

We recently started writing software to make use of a real-time clock IC, and found to our chagrin that the chip was missing a rather useful function, namely elapsed time in seconds since the standard epoch (January 1, 1970, midnight UTC).Let me back up a second.A real-time clock/calendar (RTC) is a micropower chip that has an oscillator on it that keeps counting time, independent of main system power. Usually this is done with a lithium battery that can power the RTC for years, so that even...


VHDL tutorial - A practical example - part 2 - VHDL coding

Gene Breniman May 27, 2011

In part 1 of this series we focused on the hardware design, including some of the VHDL definitions of the I/O characteristics of the CPLD part.  In part 2, we will describe the VHDL logic of the CPLD for this design.

With any design, the first step to gather the requirements for the job at hand.  From part 1 of this article, I have copied two sections that address some of the requirements for the CPLD design.

The data acquisition engine has the...


Tracing code and checking timings

Richard Dorfner May 25, 20115 comments

Debugging resource limited systemsApplications writers that write code on large systems have it easy. Well, perhaps not easy, but certainly easier. There are some things that they don't have to worry about and there is a huge array of tools available to them when it comes time to debug. The have choices in their toolsets, lots of choices. They also have a large selection of available methods for getting debugging information out to them such as log files, proc entries, pop up dialog boxes or...


VHDL tutorial - A practical example - part 1 - Hardware

Gene Breniman May 18, 20111 comment

In previous posts I described some simple VHDL examples.  This time let's try something a little more complex. This is part one of a multiple part article.  This is intended to be a detailed description of one of several initial designs that I developed for a client.  This design never made it into a product, but a similar design was used and is currently being produced.  As a considerable amount of work was put into this effort, I decided to share this design...


Byte and Switch (Part 1)

Jason Sachs April 26, 201114 comments

Imagine 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 engineers: what do you put between the microcontroller and the electromagnet?We used to think this kind of question was too easy, but there are a surprising number of subtleties here (and maybe a surprising number of job candidates that were missing...


Good old multiplexed keypad in an embedded system

Jayaraman Kiruthi Vasan April 17, 20118 comments

Good old multiplexed keypad in embedded systems

(My www.embeddedrelated.com Blog No.1)

Touch-screens, rotary encoder switches and other navigational aids rule the user interface these days.  Navigation through menus and sub-menus is child’s play as icons and thumbnails rule the screen.

 

Jumping from one screen to another, switching between programs and event notification pop-ups are made possible due to high...


VHDL tutorial - Creating a hierarchical design

Gene Breniman May 22, 20086 comments

In earlier blog entries I introduced some of the basic VHDL concepts. First, developing a function ('VHDL tutorial') and later verifying and refining it ('VHDL tutorial - part 2 - Testbench' and 'VHDL tutorial - combining clocked and sequential logic'). In this entry I will describe how to...


VHDL tutorial - combining clocked and sequential logic

Gene Breniman March 3, 2008

In an earlier article on VHDL programming ("VHDL tutorial" and "VHDL tutorial - part 2 - Testbench", I described a design for providing a programmable clock divider for a ADC sequencer. In this example, I showed how to generate a clock signal (ADCClk), that was to be programmable over a series of fixed rates (20MHz, 10MHz, 4MHz, 2MHz, 1MHz and 400KHz), given a master clock rate of 40MHz. A reader of that article had written to ask if it was possible to extend the design to...


Designing Embedded Systems with FPGA-2

Pragnesh Patel November 13, 200710 comments

In last part, we created hardware design of basic system. The next step is to generate (compile) hardware design. Compiled hardware design is known as bit-stream andstored in *.bit file. To compile hardware, use hardware->generate hardware tab. The complete hardware design generation takes several seconds to several minutes depending on computer speed and design complexity. In back ground, the whole design process involves many different steps including synthesis, placement, routing and...


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...


When a Mongoose met a MicroPython, part I

Sergio 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.


Embedded Software Creation II - European Normative & Legislation

Dr. Maykel Alonso December 20, 20116 comments

In this post I will explain the European Normative. I will answer the main questions and I will be open to answer all the doubts any of you could have. Please leave a comment and I will answer if i could.

Why I need to look and accomplish some standards? 

The main reason is if you want to comercialize the product in the European Union, if exists any European Directive that cover the product, the product must be marked with the CE mark. For USA it work in the same way by the...


Tracing code and checking timings

Richard Dorfner May 25, 20115 comments

Debugging resource limited systemsApplications writers that write code on large systems have it easy. Well, perhaps not easy, but certainly easier. There are some things that they don't have to worry about and there is a huge array of tools available to them when it comes time to debug. The have choices in their toolsets, lots of choices. They also have a large selection of available methods for getting debugging information out to them such as log files, proc entries, pop up dialog boxes or...


Handling Translations in an Embedded Project

Mattia Maldini October 13, 20234 comments

A brief walkthrough on how to handle human language translations in a low level C application. Some options are listed, each with advantages and disadvantages laid out.


Bellegram, a wireless DIY doorbell that sends you a Telegram message

Sergio R Caprile July 9, 2023

A wireless button that uses the M5 STAMP PICO and Mongoose to send a Telegram message when pressed. The code is written in C


Understanding Yocto Project Layers: A Modular Approach to Embedded Systems Development

Aaksha Jaywant September 16, 2024

In the world of embedded systems, flexibility and modularity are key to managing complex projects efficiently. The Yocto Project, a powerful build system for creating custom Linux distributions, embraces this philosophy through the use of layers. These layers are essentially sets of repositories that contain the instructions and metadata required to build a specific target image. By leveraging layers, developers can modularize their projects, reusing and sharing previously developed metadata...


Layout recomendations and tips for best performance against EMC

Dr. Maykel Alonso January 4, 2013

When making the layout of the circuit diagram, it is interesting to perform a preliminary analysis of several issues in order to minimize problems arising from electromagnetic compatibility.The analysis consists in:

Identify / Analyze components: This section will analyze the integrated components, as well as any recommendations it may have the manufacturer. We must also analyze the encapsulation possibilities which have the component.


When a Mongoose met a MicroPython, part II

Sergio R Caprile June 22, 2024

In the first part of this blog, we introduced this little framework to integrate MicroPython and Cesanta's Mongoose; where Mongoose runs when called by MicroPython and is able to run Python functions as callbacks for the events you decide in your event handler. Now we add MQTT to the equation, so we can subscribe to topics and publish messages right from MicroPython.


Intro to Microcontrollers Part 2: AVR Microcontrollers

July 11, 2013
Introduction

This is part 2 of my playing around with AVR microcontrollers. Last time, I had a basic setup which could program an AVR using the Arduino ISP. I used it to drive a simple 7-segment, multiplexed 4-digit LED display. This is a follow up where I try out some of the other features the ATTiny24A has to offer. I also decided to invest some money in an AVR Dragon programmer/debugger so I'll go over some basic playing and setup with this device. I'll also discuss some of the problems...