New Comments System (please help me test it)

Stephane Boucher October 4, 201618 comments

I thought it would take me a day or two to implement, it took almost two weeks...

But here it is, the new comments systems for blogs, heavily inspired by the forum system I developed earlier this year.  

Which means that:

  • You can easily add images, either by drag and drop or through the 'Insert Image' button
  • You can add MathML, TeX and ASCIImath equations and they will be rendered with Mathjax
  • You can add code snippets and they will be highlighted with highlights.js
  • You can edit...

Use DPLL to Lock Digital Oscillator to 1PPS Signal

Michael Morris July 24, 20162 comments
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 oscillator on the leading edge of the 1PPS signal. In many cases, this will result in adequate performance. However, in situations where simple synchronization does not provide adequate performance, digital phase-lock techniques can be applied to a...


Summer of gateware is coming (again)

Christopher Felton April 29, 20162 comments

How time flies!  I swear my last post was a summary of the 2015 summer of gateware.  This year (2016) MyHDL is participating in the Google summer of code again, for the second year, continuing as a sub-org of the Python Software Foundation organization.

This year, so far, has been amazing and inspiring.  We have had many talented students inquire about the project and contribute to myhdl and


Data Types for Control & DSP

Tim Wescott April 26, 20166 comments

There's a lot of information out there on what data types to use for digital signal processing, but there's also a lot of confusion, so the topic bears repeating.

I recently posted an entry on PID control. In that article I glossed over the data types used by showing "double" in all of my example code.  Numerically, this should work for most control problems, but it can be an extravagant use of processor resources.  There ought to be a better way to determine what precision you need...


3 Good News

Stephane Boucher March 9, 20161 comment
Good News #1

Last week, I announced a new and ambitious reward program that will be funded by the new Vendors Directory.

This week, I am happy to announce that we have our firsts two sponsors!  Quantum Leaps & Abelon Systems have agreed to pay the sponsorship fee to be listed in the new Vendors Directory.  Because of their support, there is now some money in the reward pool ($1,000) and enough to pay for the firsts 500 'beers' awarded.  Please...


The New Forum is LIVE!

Stephane Boucher February 18, 20161 comment

After months of hard word, I am very excited to introduce to you the new forum interface.  

Here are the key features:

1- Easily add images to a post by drag & dropping the images in the editor

2- Easily attach files to a post by drag & dropping the files in the editor

3- Add latex equations to a post and they will be rendered with Mathjax (tutorial)

4- Add a code snippet and surround the code with


Running Average

Mike February 15, 20166 comments

The running average filter is a useful way to reduce noise in a system.  One project I recently worked on required a 4 times frequency output from an encoder input.  The problem was the encoder is mounted to the wheel of an old truck and bearing noise was making the original algorithm generate way too many pulses.  The original algorithm worked, but the noise on the input made it useless.

I first implemented the moving average based on


Ancient History

Mike January 18, 201612 comments

The other day I was downloading an IDE for a new (to me) OS.  When I went to compile some sample code, it failed.  I went onto a forum, where I was told "if you read the release notes you'd know that the peripheral libraries are in a legacy download".  Well damn!  Looking back at my previous versions I realized I must have done that and forgotten about it.  Everything changes, and keeping up with it takes time and effort.

When I first started with microprocessors we...


Dealing With Fixed Point Fractions

Mike January 5, 20163 comments

Fixed point fractional representation always gives me a headache because I screw it up the first time I try to implement an algorithm. The difference between integer operations and fractional operations is in the overflow.  If the representation fits in the fixed point result, you can not tell the difference between fixed point integer and fixed point fractions.  When integers overflow, they lose data off the most significant bits.  When fractions overflow, they lose data off...


Mathematics and Cryptography

Mike December 14, 20153 comments

The mathematics of number theory and elliptic curves can take a life time to learn because they are very deep subjects.  As engineers we don't have time to earn PhD's in math along with all the things we have to learn just to make communications systems work.  However, a little learning can go a long way to helping make our communications systems secure - we don't need to know everything. The following articles are broken down into two realms, number theory and elliptic...


Dealing With Fixed Point Fractions

Mike January 5, 20163 comments

Fixed point fractional representation always gives me a headache because I screw it up the first time I try to implement an algorithm. The difference between integer operations and fractional operations is in the overflow.  If the representation fits in the fixed point result, you can not tell the difference between fixed point integer and fixed point fractions.  When integers overflow, they lose data off the most significant bits.  When fractions overflow, they lose data off...


Learning VHDL - Basics

Enrico Garante June 15, 20135 comments

Since FPGA are becoming more accessible to the hobbyist, learning how to use them can be really useful for certain applications, like DSP and video generation; moreover, engineers that are able to code in VHDL/Verilog are always requested on the job market.

In this tutorial I will cover the basics of Xilinx ISE and VHDL. I willl base my code on the Basys2 board from Digilent: it is really cheap (especially for students) and has a lot of features on board, as you can see from the picture...


The Spartans

Christopher Felton February 20, 20104 comments

The latest release of the Xilinx Spartan family is the Spartan6 line of FPGAs. It has been awhile since the last major Spartan released, the Spartan3, but this last year Xilinx released the Spartan6. The Xilinx Spartan family is the low cost FPGAs compared to the higher cost and high performance Virtex family. The Spartan family is derived from the Virtex architecture with some changes to reduce the cost. The Spartan3 FPGAs were derived from the Virtex-II architecture. Since the Spartan3...


Inside the Spartan-6: Using LUTs to optimize circuits

Victor Yurkovsky June 24, 20153 comments

While building a small CPU on a Spartan-6 chip I came across the same old problem: my Verilog was mapping to a lot of slices . Way more then seems reasonable. So let's dig in and see what's really going on.  

The J1 CPU (see Messing Around with a J1) is an amazingly streamlined design expressed in just over 100 lines of Verilog, and is reasonably compact at 150 Spartan-6 slices (half of that with the modifications described in the article).  But the Picoblaze is...


Free Goodies from Embedded World - Full Inventory and Upcoming Draw Live-Streaming Date

Stephane Boucher March 22, 20191 comment

Chances are that you already know that I went to Embedded World a few weeks ago and came back with a bag full of "goodies".  Initially, my vision was to do a single draw for one person to win it all, but I didn't expect to come back with so much stuff and so many development kits.   Based on your feedback, it seems like you guys agree that It wouldn't make sense for one person to win everything as no-one could make good use of all the boards and there would be lots of...


StrangeCPU #4. Microcode

Victor Yurkovsky May 13, 20137 comments
Summary:

Sliding windows containing runs of microcode.

Table of Contents:

MyHDL FPGA Tutorial II cont. (Echo, Audio Interface)

Christopher Felton September 13, 201210 comments
Introduction

To demonstrate the echo on an FPGA board an interface to an audio ADC/DAC chip will be used. The following will explain the connection to the audio codec and the HDL module used to interface.

Audio Codec Interface

I have two boards with TI AIC23b audio codecs. The AIC23 has a configuration interface (ability to program the registers) and a streaming audio interface. The SPI mode will be used to configure the codec and the I2S interface is used to send and...


Finally got a drone!

Stephane Boucher August 28, 20172 comments

As a reader of my blog, you already know that I have been making videos lately and thoroughly enjoying the process.  When I was in Germany early this summer (and went 280 km/h in a porsche!) to produce SEGGER's 25th anniversary video, the company bought a drone so we could get an aerial shot of the party (at about the 1:35 mark in this video).  Since then, I have been obsessing on buying a drone for myself and finally made the move a few weeks ago - I acquired a used DJI...


Free Goodies from Embedded World - What to Do Next?

Stephane Boucher March 6, 20193 comments

I told you I would go on a hunt for free stuff at Embedded World in order to build a bundle for someone to win.


Embedded World 2018 - The Interviews

Stephane Boucher March 21, 2018

Once again this year, I had the chance to go to Embedded World in Nuremberg Germany.  And once again this year, I brought my video equipment to try and capture some of the most interesting things at the show.  

Something new this year, I asked Jacob Beningo if he would partner with me in doing interviews with a few vendors.  I would operate the camera while Jacob would ask the right questions to the vendors to make them talk about the key products/features that...