Archives for category: Own Software

This is the final prototype of the Tesla User Interface. It was developed during the time of my diploma thesis in media computer science at the Ludwig-Maximilian University of Munich. Thanks go out to my supervisor Aurélien Tabard for a helping with this setup.

The wireless and batteryless control widgets are regular Mifare Classic 1k protocol RFID ICs by NXP Semiconductors, that have been enhanced with mechanical control element functionalities, like button, slider or rotary switch.

Few Words about the Reader Setup:


Under the white plate an Arduino is connected to two SM130 reader modules. Via two dual 4-channel analogue multiplexer/demultiplexer each of the modules itself is connected to two antennas like it can be seen in the figure above. The communication naturally proceeds through the modules. The Arduino directly controls the multiplexer, by applying a current to the multplexer’s address pins in the right way. Furthermore each module has a status LED that tells if it is ready and one LED indicating when an ID read event occurred. The detected ID information is delegated over the serial connection to the Arduino and from there further to the PC and the Processing software. This means that three serial communication connections have to be handled by the Arduino, what demands an equal baud rate. Therefore the maximum baud rate is determined by the maximum baud rate of the slowest component in the setup. And finally a picture of the wiring:


One more time a discription of serial communication between an Arduino and a Processing sketch. But this time the important steps in making up a serial connection between an random serial device to the Arduino, which itself has a another serial communication to the pc running a Processing programm.

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First of all I emphasize that unfortunately none the following attempts of reprogramming fused AVRs was successful in my case. Therefore this is more a personal documentation of what did not work, rather than a tutorial on how to get AVRs reprogrammed.

The general problem is, that once the fuse bits of an AVR are set to except an external clock source, the AVRs can in theory only be reprogrammed when they have that external clock source during the reprogramming process as well. In practice it is much more complicated.

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