USB Chipcard Reader

There are two basic types of chip card in credit card format: Those with a processor and those without. Memory chip cards have just a simple EEPROM (electrical erasable and programmable read-only memory) of type 24Cxx fitted beneath the eight contact pads. The memory size can be from 128 Byte (1 Kbit) to 2048 Byte (16 Kbit). Control of the memory is via a two-wire interface which could be either I2C or Two-Wire-Interface (TWI) depending on the card manufacturer.

Problems can arise with USB hubs that are powered from a PC when gadgets plugged into them draw too much current. This is often the case with devices fitted with USB cables that are too long or too thin, causing voltage drop. There’s no need to scrap your old USB hub, however, if you upgrade it using this little circuit and an external power supply.

Remote control using mobile phones and SMS (Text Messaging) is in great demand but many systems on sale suffer from imperfections. The ingenious new design combines powerful capabilities with low technical overheads. It has programmable AC mains switching outlets plus status reports by text message and alarm-activated delivery of GPS data. The project featured in this article employs readily available mobile phones for the GSM receiver and data output function (at no cost at all if you use discarded handsets).

Cars made by the Volkswagen/Audi group (VAG) are easy to interface to using the OBD-2 connector: the VAG-COM software allows values to be read out from the car and parameters to be set. The communications protocol used is called KW 1281. Versions of VAG-COM up to 311 require the use of an isolated interface connected to the PC’s serial port to protect both the car’s computer systems and the PC itself from possible damage.

It’s about time, you might say! After all, even if the ATmega microcontroller isn’t necessarily mega, it’s still quite popular and we feel it hasn’t really received the attention it deserves in Elektor Electronics. The Mini ATmega Board described in this article puts a change to that, and a nice application for it — our Standalone OBD2 Analyser— is featured in an accompanying article.

You can use the OBD-2 / EOBD diagnostic connector required in all recent cars to read out a lot of interesting data if you have a suitable interface adapter and a notebook computer. An even more practical solution is to use the stand-alone analyser described here, which can be used as a hand-held unit or fitted in your car. Diagnostic data is evaluated using an ATmega16 and shown on an LCD with four rows of 20 characters. Up to eight parameters can be constantly shown on the display while you’re driving. Having this information at your fingertips can be especially handy if you have car trouble.