An IR detector triggers a stepper motor to open the pet door, wait a short period of time and then close the door. Stepper motor gives precise control of door position.
A level sensing strip in the fluid signals the current level. The microcontroller controls a pump which will fill the container to the set level and then drain the container using a solenoid operated valve. Status of the system is indicated on a row of LEDs.
A hand held accelerometer is used to control a labyrinth game via microcontroller controlled servo motors. The batteries supply the servo motor power.
The microcontroller measures the fan RPM. It signals a warning if the speed goes too low or too high.
An oxygen sensor interfaced to the microcontroller measures the exhaust of an automobile (video of operation can be seen in computer monitor). A row of LEDs indicates measured oxygen content.
The chanter is mimicked using push buttons along a custom printed circuit board. Button presses as transferred via an SPI interface to the microcontroller which generates the appropriate output frequency using the DAC.
The user sets the string to tune using the keypad. A strobe light (or speaker) is used to provide the tone the string should match.
An IR detector is used to synchronize the microcontroller with the position of the spinning disk. The microcontroller strobes the disk with red, green, and blue LEDs at the apropriate rotation to indicate the time (which is read off of a clock chip).
A pacemaker is used to simulate the heart. The microcontroller measures the rate and indicates the range with a multi-color LED. A speaker alarm goes off if the rate gets too high.
An analog amplifier was designed and built to amplify the signal from a pH probe. The analog to digital converter in the microcontroller digitizes the value, the pH is calculated and displayed on the LCD.
An analog amplifier conditions the signal from the electrodes (on the heart), which is then converted to digital in the microcontroller. The microcontroller uses a speaker and light to indicate signal not present, and converts back to analog for display on an oscilloscope.
Control panel for operating pumps. The control panel allows maintaining the level of water either manually or automatically, with the level sensor either being a level transmitter or a set of float switches. The project centers on the control panel and not the water tank and pump hardware.
Using some additional analog circuitry, implemented a digital volt ohm meter. Readout is on the LCD display.
A servo motor does a 180 degree sweep of the surrounding area with an infrared range finder. Found objects are indicated by the RGB led on the board.
The microcontroller generates a morse code message and controls the output signal strength of the transmitter inside the box. (The paint can contains output load resistors for the transmitter.)