Recording Hardware & Software

PC Software Development

Since developing our first professional noise and vibration measurement products in 1986, PTP have developed a particular expertise in this market. Working with end users and experts, we have continued to develop new applications for PC and handheld computers that are innovative in their use of hardware and software to provide cost effective instrumentation for environmental noise measurement, machinery condition monitoring, and the production testing of mechatronic assemblies. The development of low cost, high quality hardware for audio data recording and playback in the last few years has revolutionised our ability to develop cost-effective instrumentation: instead of developing custom DSP-powered hardware as the instrumentation front end, we can now utilise sub-£100 USB ‘sound cards’. Although these still require high-quality analogue preamplifiers to achieve measurement to the requisite standard, the net result is a much reduced product cost to that previously attained. A necessary adjunct to low cost hardware is low cost software. In the last quarter of 1999 we identified a requirement to develop a ‘toolkit’ for PC-based sound recording and playback that would provide an easy-to-use, robust, interface for applications to the Windows Multimedia subsystem. Over the Christmas break that year, the MSSRecorder  ActiveX control was born, and during the next month or two was developed into a robust mechanism for achieving basic sound recording and playback.We quickly realised that this control was applicable to a much wider range of applications than we needed ourselves. Embedding the control in a suitable general-purpose application, QuickRecord, we began marketing the control and application as inexpensive internet shareware and were pleasantly surprised by the reception it got!

Over the following years the control was enhanced and improved in many ways, and the current version of the control, MSSR210, incorporates VOX, basic audio editing facilities, the ability to directly record and replay any format of wave audio supported by the Windows Audio Compression Manager (including GSM and MP3 formats). More information about the control is available at www.ptpart.co.uk/quickrecord. With over 500 developers worldwide using the control, it has been used in diverse applications including dictation applications, call centre monitoring, radio and voice recording, and educational software as well as applications like our own in test and measurement. We have been pleased to develop special customised versions of the control for several customers with enhanced (or in one case simplified) facilities, reformulating the control where required to ease its incorporation into particular applications.

With the product sales and custom developments repaying the initial modest investment many times over, we have been extremely pleased at the success of this control and the simplicity and robustness it brings to audio applications. In early 2004 we introduced a companion ActiveX control – MSSMixer (www.ptpart.co.uk/mssmixer) – to allow simple control of the Windows Audio mixer. This is also proving a popular solution to a common problem!

Hardware

When noise and vibration experts INVC (Industrial Noise and Vibration Centre Ltd, www.invc.co.uk) wanted to offer their customers a low cost, professional quality noise annoyance recorder – with standards approval – they turned to PTP to help them. The desire was to produce a portable version of a PC noise recording and analysis package. The package, NoiseMaster, was developed by us for INVC some three years ago and since that time it has undergone a number of changes to enhance its functionality and constitutes a significant development. The annoyance recorder plugs a perceived gap in the market, and our aim was to do this as economically as possible by leveraging much of the original NoiseMaster development. INVC’s idea was to put a fanless PC (based on a Mini-ITX form factor motherboard) into a case with a small TFT display, flash disk drive, numeric keypad and custom high quality preamplifier. To that end INVC assembled a prototype system with PTP being tasked to design a custom USB-controlled preamplifier and to adapt the NoiseMaster application.

As NoiseMaster had been developed using National Instruments LabWindows/CVI, providing an application-specific user interface was simple. New panels were defined so that they were visible on the small low-resolution display and hooks were provided back into the original code. With INVC based in Slough and PTP in Cambridge we were able to perform design reviews remotely. We visited with the final prototype to discuss how the unit could be put into production. It soon became clear that INVC were not really in a position to manage the day to day tasks of overseeing manufacture, not least because they were extremely busy! We were able to step in and offer to take this on for them. We now manufacture the equipment for them - they simply place an order on ourselves for the instrument and we are able to deliver the equipment to them within four weeks. This has enabled them to insulate themselves from the distractions of instrument production. Initial prototype development was carried out for less than £11000 (€16K), which included modification of the PC application, design, and prototypes of the USB-controlled preamplifier and sound card.

During the development, the numeric keypad proved to be unsatisfactory and the plan was to replace it with a touch pad to control the mouse cursor. In the initial stages of manufacture of the first two units PTP became aware of a recently introduced 7-inch S-VGA display with touchscreen that greatly enhances the final product (and which INVC believe will increase sales by at least 30%). We were able to include this display and adapt the code to support it at no extra cost.