Articles tagged “USB”
Using a VDrive to access USB flash drives from a Cambridge Z88
The VDrive is a handy module for electronic projects that need to access files on a USB flash drive. It's based around a USB host microcontroller and comes preinstalled with some firmware that provides control over the drive with simple commands sent via a serial connection (UART or SPI). A few years ago I started putting together some code to connect the module to my Cambridge Z88 computer. All I needed was a way to power the drive and a MAX232 chip to translate the computer's RS-232 interface to the VDrive's logic levels, and after around 150 lines of BBC BASIC I had a program that could show directory listings, let me browse folders, and fetch files from the USB drive to the Z88's file system.
Tape cycle frequencies and phases, plus VDrive3 support for BBC BASIC on the Sega Master System
I have now moved the tape interface circuit described in the previous entry from its breadboard prototype to a neat enclosure where I am happy to report it mostly works as well as it did before. I have spotted two issues, though. The first affects my small cassette recorder but not the large one, and is related to reading files from tape via the file IO routines (such as OPENIN then BGET# to retrieve a single byte, not from LOAD). Files are stored on tape in 256 byte blocks, and when the file is opened a whole 256 byte block is read from the tape and copied to the Master System's RAM.
BBC BASIC Electronics Sega Sega Master System Tape loader USB VDrive Z80
USB remote control receiver for PowerDVD
I enjoy watching films and mainly do so sitting at my desktop PC. This has taught me that cheap office chairs are not the most comfortable things to sit on for extended periods of time, especially when the next room contains a comfortable bean bag and a good place to stick a screen. A gap between the two rooms allows me to pass cables from one to the other, and after purchasing a 10m DVI-D cable and a USB extension lead on eBay I had both picture and sound sorted out (I use a USB sound "card"). This left me with one final problem: how to control the PC through a wall.
Comments ATmega168 ATtiny84 AVR Electronics Remote control USB
USB joypads and text on your TV courtesy of an ATmega168
Nearly a month since my last update - my, how time flies when you're having fun (or a heavy workload). I ended up building myself a cheap and cheerful SI Prog programmer for AVR development. After installing the development tools, scanning through the documentation and writing the microcontroller equivalent of Hello, World (flashing an LED on and off) I needed to find a suitable project. The first one was getting to grips with V-USB, a software USB implementation for AVRs. All you need for this are a couple of I/O pins, a few configuration file changes to set your USB device's vendor ID, product ID and device class, and a few lines of C code to actually implement your device.
VMusic2 - USB for the 83+
The TI-83+ lacks something the 84+ series has - a USB port. Enter the VMusic2. This low-cost (£25) module offers a USB host controller with a simple serial interface that can be used to read/write FAT-formatted USB mass storage devices. It can also play MP3 files straight from the drive! This is all very well, but the TI doesn't have a standard serial port either. To handle communications between the two, therefore, is a PICAXE-28X1 microcontroller. The TI can then run a program that communicates using its standard linking protocol.