Last Updated 12-Dec-2004

WHEELER SYSTEMS LTD

Over the years, we have designed, or been involved in the design of, many different products. Some of these are described here:

The X-Plorer+

The X-Plorer+ is a memory card based portable audio player for use in exhibitions, museums and Art Galleries. It is the modern development of the older Gallery Guide. MP3 encoding is used to maximise the number of hours of audio available; the unit can store up to 100 hours of audio on a Compact Flash card, with up to 9999 different tracks, each in any one of up to sixteen languages. Beside each exhibit is a four digit number, which when keyed into the unit, plays an audio description of that item. This basic capability has been enhanced by an infra-red receiver to provide automatic "tours" of an exhibition and also remote control of the unit, so when the wearer walks into a particular room, the unit will automatically play an audio track. It can also be linked to a video display to provide synchronised audio in the users choice of language.
Internally, the unit consists of a processor, ram, MP3 audio decoder and amplifier, battery and charger and a remote control interface. The unit connects to a rack for battery charging, datalogger downloads and media updates.
We have been responsible for most of the software and hardware design for this product, and many thousand have now been produced and are being used around the world.

These are some of the prototype units, and a compete rack full of XP+ units.
   

The Gallery Guide

The "Gallery Guide" is a portable CD player for use in exhibitions, museums and Art Gallery. Unlike a standard CD player, a single CD in this unit can store up to 50 hours of audio, with up to 9999 different tracks, in any one of up to eight languages. Internally, the unit consists of a CD-ROM player, processor, buffer ram, audio decoder and amplifier, battery and charger and a remote control interface. The first generation of Gallery Guides used mono ADPCM audio storage, which was limited to 40 hours of audio per CD. The current generation use MPEG encoding, which gives up to 50 hours of audio and CD quality stereo (though not both at the same time, unfortunately). The next generation, which is being designed at the moment, will store up to 100 hours on a CD. We have been responsible for a large part of the software design, most of the internal software and have assisted in the design of some of the ancillary equipment, such as chargers, data logging racks and encoding software.

The "insides" of a Gallery Guide

The Firecoder

Since 1990, Wheeler Associates has been involved in paging systems for the UK Emergency Services, primarily UK Fire Brigades, but also the Royal National Lifeboat Institute (RNLI) and other organisations around the world. The first systems were simple monitored transmitter systems for pagers, but over the years, the system has expanded to provide reliable mobilisation services which can also control printers, bells, PA systems and many other devices. 

First generation encoder card

The communication services use various different communication bearers such as Data PSTN, Voice PSTN, ISDN, Kilostream, Tetra, IP and VHF radio systems. Currently, over 70% of the UK Fire Brigades have some systems installed which are based upon our designs. Increasingly, this technology is also being sold abroad; for instance, 200 stations are now installed in Australia and seven stations in Germany.

  A "firecoder" in development

Every few years, a new design of card is done. The one below provided all the functions of both cards shown in the chassis above, and also includes voice input and output facilities, and an enhanced Data and Pocsag encoder/decoder.

As well as the hardware design, we have also been responsible for the PC based software which allows the system to be configured, tested and exercised. This is a screen shot from one of the early programs:

Originally, the bulk of the this PC software is DOS based, but all new development is currently using the Windows-9x/NT/XP environment, with a Linux version currently under development. This is the same program in its Windows incarnation:

Some new applications are now using a browser interface, which, even though it can have limitations, provides a great deal of flexibility in remotely controlling programs.

Other Paging Systems

A large number of other paging related systems have been designed, most commonly protocol converters to convert various protocols into a form suitable to drive paging systems.

Baby Cot Alarm

This project provides a monitoring service for babies in hospital cots. This can detect that the baby has been removed, or that it's heartbeat or breathing has stopped. Once triggered, the cot itself sounds an alarm, and sends a message back to a central PC, which can alert nursing staff, and if required, lock doors to prevent the baby being stolen. Swipe cards are used to identify the mother. Our involvment in this project has been primarily the control and communication software.

CP/M Office Computer (1980's)

Prior to the "invention" of the PC, general purpose office computers were often based on CP/M systems. The machine we designed used a Z80 processor running at 4MHz, with 64K or 256K of memory, 10Mbyte hard disk, a 80x24 text screen and a 300 or 1200 baud modem. Compared to a modern PC, it almost seems impossible that such a machine would be any use, but nearly 2000 of them were built and provided offices with Word Processing, Accounts, Spreadsheets, access to Prestel (the nearest thing to the Internet in the UK at that time) and Telex. At the time, printers were mostly "just about legible" dot-matrix printers, but the lucky few had a "daisywheel" printer, which provided better than typewriter quality, albeit at the expense of a lot of noise!

I still have one of these machines running, though I suspect there are very few still in existence. Believe it or not, at the time, the case design was considered quite contemporary!

Other Projects

Design and development of various embedded systems for the environmental monitoring industry, including microprocessor software and communications links.

Design of the digital and software sections of a Digital Storage Oscilloscope plug-in card for the IBM-PC. This card had two channels, with sampling up to 20M samples/second, and full control from the IBM-PC keyboard.

Design of an interface card and software to store and retrieve high speed, newspaper facsimile signals using an IBM-AT computer with high capacity SCSI disk drives.

Design and development of IBM-PC based interface card to emulate the BBC machines' analogue, parallel, printer and sound ports.

Design and implementation of two different database systems for the semiconductor industry using relational database techniques and a combination of SQL, Informix 4th Generation Language and "c" software.

Design and implementation of an extensive semiconductor data analysis system using "c"  (12000 lines of code), including extraction of relevant data from an existing VAX based database.

Design and coding of a distributed database for tracking vendor production performance & defect analysis, using "c" language, replacing an existing dBase database.

Hardware and software design of several microcontroller products, generally based upon the 8048/8051 series.

Design and coding of a PC based radiopaging controller, using memory resident, window based software written in "c" and 8051 assembler.

Implementation of ATE system for testing ECL logic chips, including analogue testing using IEEE-488 instrumentation.