Design Examples

Antistatic monitor/data logger

The unit Mike is holding in the picture right, monitors anti-static wrist-straps and footware,  and shows the result on an LCD display.

It can also print out details and store all the readings along with a user identity number for later analysis as a data logger.

Mike has designed circuits & written software for brushless DC motor control to provide wave shaping, soft starting & speed control amongst other functions. This software is written in Assembly Language so that small very low cost microcontrollers can be used for large quantity production, these typically only have a small amount of program space, prohibiting the use of high level languages. Another advantage of these micros is that they have internal program which can be secured against copying, thus protecting the software investment in the product.

Mike @ MikeDaviesElectronics.co.uk

Lens Measuring Calculator

This unit uses a flash microcontroller to take reading from a linear displacement measure, and using values for refractive index set by push buttons, the software calculates the radius and optical strength in Dioptres.

Tennis Score-Board

This is a portable unit the size of a large briefcase, designed to hang on the fence of a tennis court, and show the score using 40mm tall fluorescent yellow characters. A radio 'Key-Fob' with 2 buttons is used to remotely increment each player's score. Being battery powered, low power consumption was a critical factor in the design of the microprocessor based circuit.

Military Joystick interface designs

Daco Scientific Ltd of Aldermaston in Berkshire manufacture military and ruggedised Joysticks & Tracker-Balls. Mike has designed interfaces for various new ranges of Joysticks, many of which are for use in Helicopters. The joystick positions are measure with 10 or 12 bit A/Ds, with out of range error checking.

Software calibration is used to set zero & full scale (to do away with trimpots etc requiring manual adjustments), with the calibration held in on-board EEPROM (non-volatile memory). Signals are sent via RS485 or RS232 data lines.

Motor Control Microcontroller Software