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]
This project is a digital temperature controller able to be used both for heating and cooling.
The temperature controlling system maintains a user programmable room temperature where air conditionars are not provided.For this purpose we need a cooler and a heater.Cooler is used for decreasing temperature and heater is used for increasing temperature.This project also shows the real time temperature in degree centigrate.It can be used in any season.
AT89S52 Room Heater/Cooler Temperature Controller - [Link]
I really liked the idea of controlling my “Home Theatre” lights with a remote (TV or other), this would save me the exhausting task of heaving myself off the couch to turn the lights on or off.
I found one of my remotes has a spare power button, its one of those stupid “universal” remotes that comes with DVD players or TVs but only work if you have all the same brand equipment, I don’t so this made a good option for a light switch.
Remote Controlled Home Theatre Lights - [Link]
soldersplash.co.uk folks are creating a 24 channel Servo controller. It’s controllable over SPI or USB and can be stacked on top of our SplashBase board to enable network control. Up to 5 of these can be used to enable control of 120 servos in total.
24 Channel Servo Controller- [Link]
Computer Precision for Power Tools @ NYTimes.com – [via]
WOODWORKING is a tricky skill to master. Students learn to measure carefully before they reach for a saw, and to cut as true to the design as hand and eye allow. But, even so, precise cutting is a painstaking job, full of pitfalls and mismatched moldings.
Alec Rivers, a Ph.D. student at M.I.T., guides a cutting tool through wood by watching a computer screen.
Now computers and their tireless calculations may bolster the skills of many people who want to create well-cut picture frames, inlays or furniture but lack the dexterity.
Alec Rivers, a Ph.D. student at the Massachusetts Institute of Technology, and colleagues have created a prototype for a compact, computerized addition to power tools that automatically performs precision measuring and cutting.
The system, which has a tiny camera, motors and a video screen, takes part of the pain out of woodworking, by using what Mr. Rivers calls “tool GPS.”
Computer Precision for Power Tools - [Link]
A microcontroller-based voltage cutoff circuit, currently in use on several motorcycles. It is designed to monitor the voltage level for the battery, and activate an accessory circuit when the level is sufficiently high. If the level drops below a calibrated level, the accessories are cut off.
Low-Voltage Cutoff Switch - [Link]
Irdroid v2.0 is advanced version of the Irdroid remote control hardware. The unit is standalone, powered by 12V DC adapter and it has a bluetooth communication module. The unit features a infra-red remote control for android and a Bluetooth Music receiver in one. The module can be used simultaneously to control home TV/AV equipment and to turn any speaker into a wireless bluetooth speakers.
Irdroid v2.0 – universal remote for Android - [Link]
The BTSwitch project was developed to switch electric devices (lamps…) using an Android smartphone.
In the following video, you can watch the device working, while in the next pages you can find some technical details… enjoy your reading!
BTSwitch – Switch electric devices using an Android Smartphone - [Link]