These displays made by Cherry were used in Williams and Data East pinball machines. But they still can serve as great resource for embedded projects like this one. It is driven by PIC 18F452 microcontroller that controls HV display through CMOS 4514 BCD decoder.

There is also a DS3232 clock with battery backup so it is possible to display reliable time. Probably the hardest thing in this project is to run display which requires high voltage. But this is done with MAX1771 voltage driver. Clock is assembled on a single PCB which is pretty large ~1 foot (305mm).

This device is designed to turn lights on when entering room and turn off after some time. As author says: “It’s an overkill of what is supposed to be a simple switch with a timer when I open/close my door. Anyway, it is modular+wireless and that’s what I like.” so the interesting part is that it is a remotely controlled device. The switch is the previous device that is a dual channel IR remote control.  So this module only detects presence of human in the room and sends commands through RC5 to remote switch where lamp wires are attached.

Project is based on PIC 12F675 microcontroller which detects obstacles with Sharp IS471F sensor with two transmitting IR LEDs. Device also excludes ambient light with CdS cell – so no activation due day light presence.  When someone enters room automat emulates RC5 command and sends it with another IR LED.

This is a great project because it is a complete solution to run your own animations on Illuminatrix during Burining Man 2010. Project itself is pretty complex one that consists of 16 distinct PCBs built around PIC16F1827 on each that control 3 LED drivers for every color of RGB LEDs.

All these slave boards are controlled by master board run by PIC18F26J50 microcontroller that sends data via I2C interface. Animations are stored in SD card so animations are run one by one, or user can enter animation ID with PS/2 keyboard and view own animation. Well this is great stuff for shows.

This circuit does what the name says – it reads temperature of an object and then adjusts PWM signal that turns fan. So the hotter – the more intense cooling will be.

Controller is based on PIC12F675 microcontroller that reads temperature from LM35 temperature sensor via ADC channel. Then ADC value is converted to temperature. Fan controller can be used anywhere where cooling is needed. Mainly it will fit on a PC for cooling hard drives, or other gadgets.

Don’t hurry to throw old stuff away – they might be interesting and useful for some projects. Check out this alarm system built around modem. Alarm system itself consists of PIC microcontroller and PIR sensor. When someone is detected in the room microcontroller dials a number to alert the user.

Microcontroller communicates with modem via RS232 interface. There is a DS275 chip used instead of well known MAX232 – this way circuit becomes even simpler as there is no need for caps. As there is only one sensor at present probably it would be great to expand project to secure more objects by adding more detectors.