Miscellaneous Project Examples

MP3 based Talking Sign using a Rabbit 2000 and Micronas 3507 MP3 decoder

This project was to develop a networked Ethernet or RS485 accessed speaking information point controlled by pushbutton and 433MHz based radio access.

The MP3 standard was chosen to compress audio files prior to transmision to the sign from a central terminal and ultimate storage within the information point itself. The information point link access protocol chosen was the sign industry standard Vultron message specification, various user extensions were developed to extend this protocol to add MP3 file transfer ability.

The existing installation point infrastructure could either be RS485 or Ethernet hence a dual solution was developed. The software was developed using Z World Dynamic C.

Teletext Product for Business Services

The objective of this project was to port an existing product such that it could process several "packet 31"services simultaneously with decryption and error correction functions. The new product used the Motorola Coldfire 68K micro controller and a newly released Philips Multimedia video data acquisition chip. The new code was developed using tools from Diab Data including their SDS SingleStep debugger and compiler.

Digital Camera Interface

The work described below interfaces to a camera module utilising the VV5404 ST (formerly Vision) camera module. This work was in two parts, the first part required development of a driver using an existing interface chip. The second part required interfacing to the camera module directly, bypassing the interface chip.

The interface chip solution was known only to be able to produce 2-3 video frames per second, this solution was developed initially in the event of needing a partial solution very quickly or as a fall back.

The client requirement was for a direct driver solution that did not require the interface chip. The diver and associated hardware was to produce a minimum of 15 frames per second. In fact the direct driver solution produced was capable of handling the 30 frames per second maximum capability of the camera module itself, this was subject to final choice of processor speed after considering on-going parallel task processing.

The driver code handled a 4 bit wide parallel video bus from the camera module that contained embedded command and control sequences along with blank, black and visible image video lines. The driver also detected, decoded and acted upon control sequences, dissected required visible video and presented this information to a higher level process in real time. The driver also handled frame, line and LSB/MSB nybble synchronisation. Development was initially performed on a PC utilising an ISA prototyping card before porting to the final embedded hardware.

Raycomm are a UK based, custom software and electronics design and development service company creating bespoke electronic products, mobile device software applications, backend web server software and e-commerce database software.