I have worked on a number of micro controller projects using PIC18 devices, here are some examples:
This unit was designed to monitor and control a domestic swimming pool installation. It monitors all relevant temperatures to control the solar panel switching. The algorithm was tuned to obtain the most heat from these panels without ever cooling the water when the sun temperature is weak. It also switches the pump on and off and monitors the water pressure.
During the winter it controls a fan heater to prevent frost damage while switching on the pump in severe conditions.
All information is data logged and stored. It is a standalone unit fitted within the pump house but linked to a PC situated within the house via a wireless link, using two XBEE units. The house PC runs a VB application to monitor the results and graphically display the data as shown in the attached picture.
The application also allows remote control of all pool equipment to override the automated functions.
All electronics, firmware and VB application were designed / written exclusively by myself and completed with 6 weeks.
I developed this device for my own personal use as I could not find anything on the market that was suitable. I have gates at the front of my garden where I mount a transmitter device, The transmitter sends out a signal when triggered by a reed adjacent to a magnet as the gate is opened. This signal is picked up by receivers located in two different rooms in my house plus one in my work shop in the back garden. The receiver unit can either sound a buzzer for a few seconds or play the opening to a song. I also have a transmitter in a garden shed located in the front garden to detect if that door is opened. The receiver was designed to accept up to eight different transmitters although I am only using two at the moment. Individual LEDs indicate which transmitter has activated and the sound can be muted by pressing the green button that then illuminates showing the unit is in mute mode. The volume cane be adjusted up and down by the use of the two red buttons. The range is 100m and the PP9 battery in the remote transmitter lasts about 9 months
This device is used to measure the volume of fluid used by one or more drip bags fed into a patient.
The measurement sensor is a load cell that feeds a 24bit ADC. The displays consist of two LCD screens, one to give the volume used by the current drip bag and the other to give the volume used over multiple drip bags.
The unit contains both hardware and software averaging to prevent vibrations from the IV pump from effecting the accuracy and ensuring stable display readings. Powered from an external 9V DC supply or internal rechargeable batteries. Control is via a simple infer-red sensor to avoid touching the scales.
I have developed two Leak detection devices, an 8 channel model shown in the picture above (without the front panel) and a larger 16 channel model. The units have a main Alarm and fault relays plus an audible alarm. Each channel can sense detect a programmable external resistance and detect an open circuit fault. It also has individual alarm relays for each channel plus individual protected power sources. The unit data logs all activity. On the 16 channel model there is also a Modbus Interface to allow for remote communication
I have developed two Leak detection devices, an 8 channel model shown in the picture above (without the front panel) and a larger 12 channel model. The units have a main Alarm and fault relays . The units can interface to various remote heat and smoke detectors which it powers via individual protected power sources. . On the 12 channel model there is also a Modbus Interface to allow for remote communication
This is an Athletics track gun replacement system. It is designed to replace the use of a starting gun in field events. It consists of one transmitter and multiple receiver units place around the track to broadcast the start sound. This can be a simple tone or a gun simulation sound.
A device to accurately measure the earths magnetic field. The device can data log all the results to an SC card that can be up loaded to a PC.
This car was designed to follow a black lane painted on a light background. It had optical IR sensors back and front to detect the presence of black and white. It also had ultra sonic sensors front and back to detect the presence of an object.
The robot was fitted with left and right stepper motors to control the drive. The firmware was designed for the robot car to travel forwards following the black line until the ultra sonic sensor detected an object less than six inches away. In which case the car would switch to reverse and follow the black line backwards until a rear object was detected.
The whole project was designed, built and fully tested within three weeks.
Various devices to fire lasers and measure the angles
The unit will be used primarily to test and demonstrate multi-channel data acquisition set-ups such as oscilloscopes and transient recorder systems/ data loggers. Once the instrumentation is set up and configured to the correct settings the "Waveform player" unit would be used to give "real" signals to the system to check that trigger levels, time bases and amplitude levels are set correctly.
The signals to be replayed will be saved waveforms that have previously been captured by similar data acquisition systems. The unit will have four channel outputs that can all output individual waveforms at a fixed 1M/s rate simultaneously. The waveforms will be read from an SD card that can be inserted directly into the unit.
All operations will be from one micro controller that has a user interface that consists of a few buttons and an LCD display.
The control for this high-speed function was complex and required the use of a high-speed gate array in conjunction with the PIC micro controller. The four-layer PCB is very dense with SMT components fitted to both sides. The prototype has now been approved by the customer and currently a production batch is being built.
The purpose of the Anniversary Reminder is to provide a convenient and automatic reminder of anniversaries, with appropriate messages and sound. The unit will constantly display a reminder of the number of days passed since a birthday or anniversary.
On the yearly anniversary of the event, from 9am in the morning to 6pm at night the unit will output the first few lines a simple musical cerebration of the event such as "Happy Birthday To You". Again, the whole project was designed, built and fully tested within a few weeks.
This device was designed to control the exposure of MS patients to blue light at specific points in time to regulate their circadian rhythms (sleep cycle). Switches will be mounted to the hinge on the glasses so that it can be determined if patient was wearing them when the LED's were on.
The device had to meet the following specific targets:
Together with the PC user interface screens to upload the data and to program the LED events.
The design has now been implemented on a custom PCB and production units are being assembled.
The application was to read audio files from a FAT32 formatted SD card and play then through a low power amplifier. This was successfully implemented as a prototype module and is currently being evaluated by the customer.
This project was to design an LED control system that would simulate the flashing navigation buoys situated in harbours and estuaries. The LED's would be fitted within a map of the particular coastal area of interest and each one would flash on and off exactly matching the flash rate of each navigation buoy.
The system I designed could support up to 80 LEDs organised into twenty groups of four. Each group could then be programmed with an individual flashing characteristic.
The overall brightness of the LED's is controlled by a pulse width modulation method using the current ambient light detected by a light sensitive resistor. The over setup of each groups timing is programmed from a user-friendly VB windows application via a USB interface.
This is a game to align mirrors to direct a laser to a target.
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