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Showing posts from May, 2006

Moving code from ESP8266 to ESP32

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A while ago I made a mashup of Dan Royer's code CNC 2 Axis Demo with my own code for trapezoidal motion stepper and servo control for ESP8266.

I assumed porting the code to the ESP32 would be trivial, and that was true for the most part: changes like library name being Wifi.h instead of Wifi8266.h were not a problem. UDP now does not like multicharacter writes but you can use print instead. So far so good.

However, when it came to the interrupt code I was stuck with the stepper interrupt causing an exception sometimes. And to make things weirder, the servo interrupt worked flawlessly (both of them had the IRAM_ATTR directive if you ask me).

Going little by little, I could narrow down the culprit to a floating point operation during the interrupt, that would cause problems sometimes but not always. Browsing around I found this post. Where the solution was simple: do not use floats within the interrupt routines but doubles. The reason was the float calculation would be performed by…

What if ... ?

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Imagine your computer gets a new type of malware that makes it download certain URLs every now and then. Imagine that software creates a special HTTP request with a fake "Referer:" header. Imagine that the purpose of that is to pretend that you are clicking on an advertising link. Imagine that the mentioned links are ads of porno sites. Imagine the software includes an engine to spread itself on your local network. Imagine your boss starts monitoring the employees network activities so you are caught red handed, at least apparently. Imagine that you are fired because of your alleged browsing activities.

Now stop imagining.

It might already happened to one of my clients and his colleague, both fired for the same reason (porn surfing at work) they claim it is wrong because they did not do that. I cannot tell you for sure because their former company is not interested in researching this matter any further.

However, neither the cookies nor the temporal internet files nor the URL …

Newer Ubuntu 6.06

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In a previous post I explained how I got my laptop running SuSE Linux 10.0. But I was not happy with the way Linux was working on my Acer laptop. Although I managed to get everything working ok (except the internal memory card reader) I was not very happy about the power management. I was not happy it took me some effort (including recompiling the kernel) to get audio working. But after all it worked.

I have been giving away Ubuntu CD-ROMs to my students since 4.10 and I have installed Ubuntu to my brother's computer and both (my brother and his computer) have been happily working since then. It is a pity MP3 or Divx are not supported out of the box. Printing and OpenOffice and GIMP have been working like a charm.

This time I thought maybe I should give Ubuntu are try, so I downloaded the latest beta (Dapper flight 7) but instead of Ubuntu I took Kubuntu, which is a blue-ish KDE-based versus Gnome-based Ubuntu. The new Live Cd includes a more or less painless built-in graphical inst…

Mother's day shopping spree

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I saw a couple of items on a PCCITY brochure that catch my eye. First one was the Freecom MediaPlayer-35 with a 250GB HD. I bought last summer a similar device from EasyBuy but I sold it after the summer as it was only 40GB capacity (though the fact it was USB-powered and only 2.5" made it quite portable). This unit is based on the use of 3.5" IDE hard disks which are cheaper and higher capacity than 2.5" cousins. This unit like many others in the market will handle your DivX, MP3 and JPG files so you can bore or scare to death your friends (worth mentioning it can also handle OGG audio). But it can also came with the relatively new feature of a LAN connection so you can also play contents from a Windows (or Samba) share on your home network. Network connection is just for streaming and video/music/photo files are transferred using USB 2.0. The unit can also play your ripped DVDs, menu included. Outputs are quite complete, including composite, analog audio, coax audio a…

Nice ad

They are playing this one now in Spain. And it seems that youtube has not a problem with you posting an ad even if your do not hold the copyrights of that ad. I guess this is what ads are for. Anyway, I think it is a funny ad.