by brmarcum @ instructables.com:
I hate Christmas tree lights.
Well not really, I just don’t enjoy having to climb under the tree every time I want to plug in or unplug the lights. In the interest of saving my sanity, I decided to build a motion activated switch that can power the lights for me. It has an integrated adjustable timer so they will stay on for as long or as short as I want. Here’s a video showing the final test on the fish tank light.
Motion Activated AC Switch - [Link]
Jaanus Kalde made this 32 channel light dimmer project, that is available at Github:
I needed a computer controllable 32 channel light dimmer for an art installation. After looking around a bit I found out that there isn’t even a Arduino shield for the work. So I made a quick 4 channel stackable board to control lights. The board uses SHARP thyristor based solid state relays to switch mains voltage. As normal with thyristors – all the outputs can be used as dimmers through zero-crossing detection. All outputs are able to handle 0.9 A / 200 W. We connected 40 W incandescent light bulbs to it but you can control whatever with it – lights, electronics, computers, motors etc.
32 channel mains lamp controller - [Link]
Andrianakis Haris informed us about his latest project. It’s a digital Thermostat for energy saving fireplaces. He writes:
In the need of my new homemade energy saving fireplace (which boils water for the radiator) i designed and built a digital thermostat. The idea to design my own thermostat came when i came across with the following problem.
When i first fire the fireplace the water in the boiler around the fireplace is cool. After a few minutes the fireplace warms the water enough so that the water temp exceeds the thermostat limit. The thermostat changes state and drives an electric valve to move the water from the fireplace boiler to the radiators. The electric valve is slow enough and takes a few minutes to make a full turn. While the water is moving from the fireplace boiler to the radiators, circularly cool water is coming back in the fireplace boiler from the radiators. Τhe water temp in the fireplace boiler is getting cooler and after a few minutes falls under thermostat’s limit. The thermostat changes state and stops the valve from driving the water to radiators. This happens again and again until the whole amount of water in the radiators is get warm.
Thermostat V1.0 for energy saving fireplaces - [Link]
Gaurav Chaudhary writes:
This little project will demonstrate how you can build NEC protocol based Infrared Remote Control to use with various NEC Protocol IR receivers. actually there are lots of projects out there to accomplish this task but i have to write my own code because of too many requests on this IR(infrared) Remote Control Relay Board with PIC 12F675 Microcontroller people keep asking “Where is the Transmitter for this” although you can use any NEC protocol based remote ,but i just wanted to build one by my self. so here it is.
NEC Protocol Infrared remote control with a microcontroller - [Link]
Attiny 2313 V-USB Media Volume Control. [via]
My most rewarding projects are the ones which i actually use. I like my audio gear so, this was the perfect companion project! On my desk i have a headphone amplifier for my AKG K702′s headphones, below it i have my self built Onixia integrated amplifier for my bookshelf speakers. I have been thinking about making a global volume control for both devices for quite some time… here is the results of my efforts.
Attiny 2313 V-USB Media Volume Control - [Link]
Paul over at Dorkbotpdx has written an article about his DMX lighting sequence player:
Portland CORE effigy at Burning Man will be using DMX controlled lighting this year. At least that’s the plan, but a low-cost and low-power way to automatically play the lighting sequence (without a PC) is needed. Here’s a little board I made for the purpose.
DMX lighting sequence player - [Link]
The RFID (Radio frequency identification) technology steps-up in the modern age in the field of access system, identification, protection system and so many places. In this project, we are using this as an door opening as well as door closing system based on the RFID card number identification. [via contact form]
RFID Based Door Opening System - [Link]
new projects on Open-electronics.org:
Connected to a burglar alarm or fire alarm in the event of making phone calls playing voice messages. Controlled via DTMF actuators can operate on the spot.
In recent years we have introduced several telecontrols based on the SIM900 GSM module. We released schematics and code for a gate opener (that activates when receiveing a call from a given number), a GSM thermostat to manage the temperature of remote houses with simple text messages, a remote alarm control with DTMF and, last but not least, a remote alarm with I/O and controlled via calls or SMS.
Many of these tools send text messages or place phone calls in response to changes to the electrical inputs. In some cases, especially when the receiver is a human, nothing is like a voice that clearly yields you screaming “fire in progress!”, or”thieves in the house!” etc.
GSM Voice Dialer with Automation Control - [Link]
Zak Kemble build an AVR based PWM fan controller. He writes:
So this is a bit of a continuation on my 555 timer based PWM controllers, but now using microcontrollers and MOSFETs instead of 555 ICs and transistors. I made 2 versions, one with switches for speeding up and down and the other with a potentiometer like the previous controllers. I used ATtiny25 controllers running at 31.25KHz (8MHz internal RC / 256 prescaler) with a 3.3V supply, the MOSFETs I used are STP36NF06L with 0.045Rds and 2.5Vgs max, perfect for 3.3V, the MOSFETs only generate ~180mW of heat at 2A ((0.045Rds * (2A * 2)) = 0.18W) so no heatsink needed, you can barely feel them getting warm.
AVR microcontroller based PWM fan controller - [Link]
Ktulu @ users.ininet.hu/ktulu/ writes:
The heart of the unit is an 8 bit PIC16F74 microcontroller from Microchip. It’s main task is to constantly monitor the room temperature trough a 1–wire digital thermometer IC, a DS1820 from Maxim, and to switch a relay on or off, that controls the gas boiler accordingly.The system also features a color LCD, which was removed from an old mobile phone, a few LED’s, an LDR sensor for night mode and a couple of pushbuttons.
PIC16F74 – Room thermostat with colour LCD - [Link]