Read only memory or ROM comes in various shapes and sizes – the most famous (maybe) is the CD-ROM (Compact Disk). CD writters make use of lasers to modify the pits so that they would represent numbers. Another type of less famous ROM is the EEPROM – electronically erasable programmable read only memory where it only needs either SPI, I2C, Parallel or 1-wire communication to read and access this ROM from SV3ORA is grand – its made up entirely of inductors, it doesn’t need any special protocol just a pulse and you will get your data.
How do we write to pieces of bloody coils? Inductors are considered to be AC passives – they usually operate using AC inputs or pulses, they dont work on DC inputs and anything that can saturate them :). This project makes use of a pulse that will generate a magnetic field around the wire and depending on the configuration of the wire, weather it passes through the center of the coil or not will generate a digital value. So when the wire enters the coil its a logic 1 when it doesn’t its a logic 0 – see the picture below as a bit of illustration.
When you finished ‘writing’/tying your data on the cores it will look like the first picture – to access your data you will then need to provide pulses – neat huh?