Tinkering with Raspberry (and other things)

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GPRS/GSM via Serial (again)

I recently stumbled over a cheap GPRS/GSM shield made for the Arduino platform, of course on ebay, of course from China. As it was priced at a very reasonable 20 EUR (25 USD), I thought I’d go with the risk and order from China. Several weeks later it finally arrived and, I couldn’t believe that at first, worked out of the box.

This is how it looks. If you get interested in one of these gadgets, just search for “GSM Arduino” on ebay, that should do the trick.


It’s a SIM900 based design and has a real time clock (plus buffer battery) on the back. A full description of all the possible AT-commands can be found here. It is basically the same shield that can be bought from Seedstudio, but much cheaper. A description with some sample sourcecode (that is working!) can be found at the Geeetech-Wiki pages. Continue reading



Short message texting (SMS) with Huawei E220

Finally I got a second Raspberry for tinkering as the old one is now operating as my own calendar and address server (which is pretty useless if the “agencies” really can monitor and decrypt HTTPS, SSL, VPN and every other means of communication). And I have been to my “evidence vault” and found an old UMTS-modem, a Huawei E220. So the most obvious thing to do was to send and receive short message texts (SMS) via my Raspberry Pi. There are some frameworks out there that do this from scratch, but I wanted to dig a little deeper and do it by myself. So read on and I will reference some of the available tools and show you my proof of concept. Continue reading