I got a friend who works for small start-up in a rented office. His problem is that they have only a single remote control to operate the parking lot gate. They needed a device that will allow them to open the gate by using the cell phone.
I built a device that connects to a phone line and to a standard remote control. The device is actually a “docking station” for the remote control. When a ring is detected the device will “press” the gate-open button on the remote control.
Telephone Operated Car-Parking Remote-Control – [Link]
Allows to remotely manage the heating or cooling of any room. It can also notify, via SMS or phone call, when the sensed temperature falls out the set limit value or the alarm input is active.
All commands related to the control and settings of the device are sent via SMS.
There are three operating modes: forced (M), automatic (A) and enslaved (T); those modes can be set with a SMS or with a local button.
To fully integrate the device with the existing system, our unit can also work as a remote alarm: it has an opto-isolated input at tension level that can be connected to the boiler malfunction indicator and set to be adapted to the different functioning conditions (in order to send an alarm if it receives tension over the threshold or if it is at zero volts); in this way, if the system gets blocked (due to an obstruction in the chimney, the excessive lowering of fluid pressure in the radiators, lack of gas, etc.), the system remotely communicates the fault with an alarm SMS or a phone call.
The alarm on the opto-isolated input is valid only when the circuit is working in automatic mode (A).
That’s not all: there is also a thermal alarm that goes off when the sensed temperature in the room exceeds the limit set by the user, that is it exceeds the maximum threshold or goes below the minimum one; the same as for the one connected to the boiler indicator, the thermal alarm can determine the sending of SMS or phone calls. The circuit can store up to eight phone numbers to which send the alarms as SMSs or simple calls.
GSM Remote Control – Temperature Control - [Link]
A Gas Water Heater controller built around a netduino-mini, a DS1307 clock and a HiTech HS-6635HB servo. [via]
Gas Water Heater controller built around a netduino-mini, a DS1307 clock and a servo – [Link]
Instructables user fraganator writes:
Having a hardware interface to your favourite music / DJ / VJ software can really open up doors in your creativity. The most widespread form of hardware control to your PC for such applications is a MIDI based controller.
A MIDI controller can send and receive MIDI messages to your PC, allowing direct control of your software. Not only that, but the controls can generally be mapped to anything your like. So what might be a volume fader for one person can be an effect filter for another.
This article will describe how to build and program a custom arcade button MIDI controller, while trying to keep the price below $100. It is aimed at electronics and programming novices.
Arcade Button MIDI Controller – [Link]
robots shares his design for a reflow oven controller: [via]
I have bought [an] oven. The main reason for this was to bake some PCBs. As with every reflow oven, this one needs temperature control as well.
I have baked several pcb without problem with unmodified oven. But that might be luck, as the temperature profile is nowhere near perfect.
I have therefore decided to make some simple temp controller to take care of the whole soldering process. As my oven features fan, I will probably want to control it as well. The controller should not to need any special programmer (mega can by programmed with BP) and the board should be etch-able at home.
Reflow oven controller – [Link]
Here’s a project that shows you how to decode a tv remote control’s infrared (IR) signals and make your own IR receiver for it.
The remote control changed the way we watch TV. Some might say that it has made us even lazier. However you see it, it is important to understand how it works and how we can use it in our own projects. Most remote controls, whether for the TV, stereo or cable, operate using infrared light to transmit a command to a receiver, telling it to do something.
Infrared IR Receiver – [Link]
By watching this video, you can understand PID in just 4 minutes. More explanation is given below on this website.
Understanding PID – [Link]
rsdio presents: 1-Wire network via an SPI-compatible display controller.
To produce the 3-wire SPI™ interface required by a MAX7221 display controller (active-low CS, DIN, and CLK), this 1-Wire network serially addresses three 1-Wire switches (DS2413). The first switch creates Chip Select directly (active-low CS), the second creates the serial-data line directly (DIN), and the third switch—with the help of three exclusive-OR gates—creates the serial clock (CLK).
App note: One-wire control of SPI peripherals – [Link]
Hi every one. Today i’ll show you how to make a PWM (pulse width modulation) out of a very famous chip 555 (lm,ne any one will do) with some other parts offcourse. This is really simple and it is very handy if you want to control your leds, light bulb, servo motor or dc motor (brushless also works). My pwm can only change the duty cyle from 10% to 90% it cant do nothing more!
Very simple PWM with 555 - [Link]