Engineer from Télécom Paris
Ph.D Thesis from UPMC

Network & Security IT - Le RSI
Check news about my company

Adding light control to my home automation system

Integrating my new Philips HUE light bulbs in my home automation system, the story.
Could also be subtitled "How to find the best carrier frequency to avoid collisions when simultaneously downloading a web page and switching the light on" !!!
Click here or on the following pictures to see how it works:

IP phone to analog phone interface circuit

At work, people usually do not get an analog phone line anymore since numeric or IP phones appeared.
Click here or on the following picture to see how to connect your old analog device (modem, wireless DECT phone, Minitel) to your IP phone:

Low cost HF signal generator

I had no money to buy this state-of-the-art DDS function generator that goes up to 20 MHz, to test my HF amplifier. So, I used a few simple discrete analog components to get a signal at 20 MHz, using only two BFR96TS NPN RF transistors, 7 capacitors, 3 coils and a few resistors. Click here to get the whole story.

Shuting down and restarting a whole computer room at once : the FenyoBox (TM)

A few years ago, I had to manage a dozen of servers running in a room where the air conditionning system used to stop frequently... During each of these incidents, the temperature was going up about to 60 degrees in 10 minutes. So, I decided to build a little box able to stop the big UPS. For this to be done, I needed to drive this double-coil 60 Ampere relay :

The command part of the box is based on a microcontroller (Microchip PIC16F876) connected to a modem through a serial port (thanks to the well-known MAX232N, a +5V-powered RS-232 driver). The power part for each coil is made of a very low-cost transistor (2N2369A) driving a standard opto-coupler (CNY17) with a 2 Watt ceramic resistor in series, to get a sufficient output current. The output of the opto-coupler drives the coil.
Here are the schematics:

Here is the box (inside and outside):

The assembler code for the PIC is available here.

Analysis of the RS-232-C serial line output from a PIC 16F876A linked with a MAX232N

Here are the samples captured with a digital oscilloscope :

Changing the SCSI target ID of a disk from a Sun SPARC station 4 or 5

Top Articles:

ImageElectronic design: driving a 60A relay with a micro-controller
Use this device to drive a 60 Ampere relay in order to power on/off dozens of computers at once.

Image"new_station" patch for hostapd
Improve 802.1X authentication on wired IEEE 802 media, with this patch for hostapd.

Copy, manipulate and erase raw data on your usb flash drive. Essential to really get privacy with your files.

ImageHidden VNC server
This patch for WinVNC 4 allows you to install a hidden VNC server : no more tray icon.

ImageRaccorder son réseau d'entreprise à l'Internet
A free book about networks. First published by Eyrolles in 1997, and under terms of Creative Commons in 2006.
© A. Fenyo - F. Le Guern - S. Tardieu

IP phone to analog phone interface circuit
At work, people usually do not get an analog phone line anymore since numeric or IP phones appeared. See how to connect your old analog device (modem, wireless DECT phone, Minitel) only using your IP phone to get the network access: read this.

Very low cost 20MHz signal generator for ham radio HF power amplifiers testing
Learn how to make a 20MHz HF signal generator using a few simple discrete analog components. Moreover, see how a 33 years old Tektronix oscilloscope gives better results than a numeric one bought recently. The whole story is here.

Split tunneling with Cisco
Enabling split tunneling with Cisco IPsec VPN Linux client software is always possible: read this.

Modelling IEEE Spanning Tree protocols using an UML Class Diagram
To really understand the dependencies between the many Spanning Tree protocols, I wrote an UML class diagram describing their relationships here.

Motorized camera controlled by the telephone
This project demonstrates how to drive a camera from the telephone line, any details here.

External Links:

ImageMy Former Web Site
Since 04/26/01, I maintain a web site named Since I made many updates recently, click here to access the original content, where old informations are kept. The photo is also from 2001 :-)

ImageAgnes' Web Site
Agnes, my wife, maintains a web server where you will find plenty of original resources : free software from her own production, probability courses, exams' corrections, photos of her trips in the US... Do not hesitate to visit her site, she will be glad to see her access.log growing !

ImageCanardou's Web Site
Canardou has always been for me a friend that really matters, helping me in every situation. According to informations currently available, Canardou could be affected by the H5N1 virus. So, for a few weeks, Public Health Bird Regulations have made me forbid Canardou to walk away from our appartement. Feel free to take news about him from his personal home page.

Private Links:

ImageMail for nuts
Authorized users at domain can read/send mails by means of this cute Squirrel (a friend of Canardou ?).