Monitors the Rack box status panel, IR sensor, porch door and turns off lights. Uses an AVR ATtiny2313 microcontroller.
Multiplexer output extender
![Multiplexer output extender](https://blog.cavelab.dev/2006/09/multiplexer-output-extender/cover_hub51e5a6750f45b717c210b74d597e01d_55056_860x0_resize_q80_lanczos.jpg)
Get more digital outputs on your I/O device with a multiplexer, 3 outputs turned into 7.
Sound alarm control unit — AVR module
![Sound alarm control unit — AVR module](https://blog.cavelab.dev/2006/08/avr-sound-alarm-unit/cover_huee3dc019f0e567715a6f70520235a02f_86366_860x0_resize_q80_lanczos.jpg)
Simple unit to control three sound signals; beep, siren and buzzer. Uses an AVR ATtiny2313 microcontroller.
Fan controller with LCD — AVR powered
![Fan controller with LCD — AVR powered](https://blog.cavelab.dev/2006/08/avr-fan-controller-lcd/cover_hu97a8699224dd8dbdfa72e3e01fbc13bb_146525_860x0_resize_q80_lanczos.jpg)
Reads temperature and controls a fan using a PWM output, fan and alarm set point can be adjusted and is shown on a LCD. Uses an AVR ATmega8 microcontroller.
Emergency power off controller — controlled by 555 timers
![Emergency power off controller — controlled by 555 timers](https://blog.cavelab.dev/2006/08/emergency-power-off-controller/cover_hu088e878e333c420fbe7b6bbacf977db8_523674_860x0_resize_q80_lanczos.jpg)
Emergency stop controller for the rack box project. Uses two 555 timers.