This project is a small automatic cooling system for home theater rack. It supports 2 temperature sensors for different zones in the rack and 2 12V PWM fans (standard for PC case cooling).
There is a power switch connector for a switch mounted on the casing (will be designed and 3D printed later). A reset button is provided mostly for reprogramming purpose. There are 4 buttons for setting up temp...
Universal board for LED control.
- Atmega8/328 on board with programming connector
- PCA9685 for 16 channel PWM up to 1.5kHz (eye-safe frequency), 12 bits per channel
- cheap ULN2003 with paired outputs for 1A per channel (2-3 meters of RGB 5050 strip per connector)
- or SOT23 MOSFETs if you need more power
- BT05 bluetooth module or MAX485, control by wire or wireless. DMX512 is possible.
**555 timer based PWM LED dimmer**
This project uses PWM to turn on and off a LED (or a strip of them) really fast and changes the duty cycle (Fig.1) so that the human brain perceive it as the dimming of the LED(s). This means that the MOSFET doesn’t have to drop large amount of voltage, this makes the device very energy efficient.
This is the analogue part of the circuite for my Arduino battery charger project.
The software can be found at https://github.com/GarethDaviesLondon/PWM-Charge-Controller-Arduino.
The pin outs refer to an Arduino Nano.
The key to this project was to make the Nano go to sleep when the sun wasn't shining.
Night Light LED dimmer documentation and code are available at http://jerrykomor.com/Stuff/Arduino/Night Light.
I made this as alternative to bet site night light. I'm using a ribbon type LED trip thats stuck to the mack of a head board which hids a bit between the carvings on head board and the control module is basically a PWM controlled with 3 buttons: Up, Down, and On/Of switching and IRL540...