DRA818 Transceiver with Arduino


This is a small prototype of future TRX for 2 meters band, the goal is to make a very simple construction for mobile usage, Based on DRA818 chinese module, he use Arduino with a rotative encoder some small buttons.

Some details:

– Coverage from 144 to 146 (possible extend from 134 to 174).
– Mode VFO or Repeater (shift -600k) with 1750Hz carrier.
– Function: Scan (not implemented yet), Memory, Step (5/10/12.5/25/100k), Wide/Narrow 12.5/25Khz, Power output 5/20W (with old TRW20 PA module).
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Find and listen TETRA Network in your area

Update 9/9/2016

I have write something for non friend linux users, a script (bash) for load all components in the same time, flow-graph are also modified for 425Mhz (most common in EU for puclic networks). Download here. Unzip and put the folder in your personal folder, change the path of every file by replacing “username” ( /home/username/Telive_Run ), give permission on every file, by CHMOD 755, now, you just need to run Telive_Run.sh to start the listen of your favorite Tetra network, default file loaded with GRC is telive_1ch_simple_gr37_udp.grc

sq5bpf has release two years ago, a great software called, TELIVE.

“Telive is a program which can be used to display information like signaling, calls, SDS, location information etc from a TMO Tetra network. It is also possible to log the signalling information, listen to the audio in realtime and to record the audio. Playing the audio and re-compressing it into ogg is done via external scripts. The software is based upon modified osmocom-tetra software. Location information can be written to a KML file, to be opened in Google Earth and similar software.”

1) Install the software, you can find documentations and install scripts on GitHub
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Si4703 small simple FM radio with Arduino


Again, a FM radio project based on Si4703 breakout board with Arduino, for your bench-work, bathroom … you can listen your programmed favorites radio station, build’s very simple, The breakout provides access to SDIO and SCLK for I2C communication while RST can be used for easy resetting. I use Arduino 3.3v@8Mhz, audio output is wired to Mini PAM8403 5V 2Channel USB Power Audio Amplifier with volume Control board, (1$ on ebay), a simple push button is dedicated to change station quickly by a simple “press”, Continue reading

Monitoring your network with SIGFOX


I’have finally found an excuse to use my Akeru SigFox board, with some lines on Arduino, two libraries, and a Ethernet shield, you can monitor if your network getaway, or server, website .. what you want in fact, still alive, with a ICMP request. The akeru board is stacked with the Ethernet shield, the loop check is the defined IP adress respond to ICMP request, if not, the akeru board send a SigFox request to the SigFox network, then the callback function send a email alert.
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Obsolescence programmée, réparation d’une station de charge USB, Watt & Co CH220-5-DOCK

Article rédiger en Français, ce produit n’étant a ma connaissance vendu quand France. WATT&CO est une startup d’une dizaine de personnes, installée dans le Vaucluse.

Watt & Co CH220-5-DOCK, de son nom commercial est une station de charge USB pour téléphone mobile, j’en ai eu trois qui sont passer entre mes mains, tomber en panne quasiment au même moment, le défaut vient d’une diode qui fini par cramé et rendre inopérant le circuit, la remplacer par une équivalence permet de résoudre le problème.

Première étape, démonté l’appareil, deux vis de sécurité a retirer avec le tournevis qui va bien.
SCharge_Watt&8 (1)
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