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Plastic, a new card that allows you to store credit cards, debit cards, gift cards and frequent shopper in one. It has an e-ink screen and has security chip. Your wallet will be made once you know Plastic diet, a device that would replace most secured credit cards, debit cards, gift cards and frequent customer. The device is a card that is linked to an application on your phone (via Bluetooth). Plastic has the ability to store up to 20 cards and the application keeps a history of transactions. Does this sound familiar? This is because you probably remember the product called Coin which was introduced in 2013 or 2010 presented in 2.0 Card Like Plastc, these products attempt to store the information of different cards to choose which you want to use each time you want to use. The difference between Plastic and other cards is that Plastic can display bar-codes, frequent shopper cards or gift cards and all information can be erased remotely if it has been lost or stolen. Plastic has a scre...

Oscilloscope screen capture of output from the audio player Top - left channel Bottom - right channel Using the PIC32MX250F128B, I decided to make a simple audio player. I wanted to play back good quality audio from a large memory space - a microSD card. So, I made this WAV player that can play back 16-bit 44.1kHz WAV files with 12-bit stereo audio output. Of course that's not all it can play back. It is programmed for automatic period configuration so that the period is set on the fly based on the song sample rate. It can play back both 8-bit and 16-bit mono and stereo audio files and I have tested from 8kHz 8-bit mono to 44.1kHz 16-bit stereo. The player itself does not include an audio amplifier to drive speakers but can drive earphones. I've used an external stereo speaker for testing. The hardware is fairly simple! Using the Microchip Memory Disk Drive File System (MDDFS) library, and my previous work using the MCP4822 dual 12-bit DAC, integrating these components to make ...

Here is a stereo tape head preamplifier circuit for your PC sound card that can playback your favourite audio cassette through the PC. Audio signals from this circuit can be di Here is a stereo tape head preamplifier circuit for your PC sound card that can playback your favourite audio cassette through the PC. Audio signals from this circuit can be directly connected to the stereo-input (lineinput) socket of the PC sound card for further processing. The circuit is built around a popular stereo head preamp IC LA3161. Circuit diagram: Stereo Tape Head Preamplifier For Pc Sound Card Circuit Diagram Weak electrical signals from the playback heads are fed to pins 1 and 8 of IC1 via DC decoupling capacitors C1 and C6, respectively. Components between pins 2 and 3 and pins 6 and 7 provide adequate equalisation to the signals for a normal tape playback.  The amplified and equalised signals available at output pins 3 and 6 of IC1 are coupled to the inputs of line amplifier circuit built aro...

In this article I will discuss my own experiences about designing a USB sound card, which is the USBDAC. DAC is an acronym for Digital-to-Analog Converter because in a sound card, digital data representing the sound is converted into analog voltage that moves the speaker cone. My device is loosely based on the PCM2706 reference design. I will not go through the tecnical details but instead concentrate on my own experiences in the design of the device. This is to keep people not familiar with electronics, as well as newcomers to electronics design, interested. You will see that one working product is the result of many failed prototypes.