An LED is the device shown above. Besides red, they can also be yellow, green and blue. The letters LED stand for Light Emitting Diode. If you are unfamiliar with diodes, take a moment to review the components in the Basic Components Tutorial. The important thing to remember about diodes (including LEDs) is that current can only flow in one direction.
To make an LED work, you need a voltage supply and a resistor. If you try to use an LED without a resistor, you will probably burn out the LED. The LED has very little resistance so large amounts of current will try to flow through it unless you limit the current with a resistor. If you try to use an LED without a power supply, you will be highly disappointed.
Learning to use LEDs and Transistors – [Link]
This project is a 3-digit digital thermometer easy to build for beginner or hobbyits.PIC16F628 used to read digital value
of temperature from a DS1820 sensor.All 7-segments drived by power logic 8-bit shift register TPIC6B595 with open collector output. For the 7-segment need 12V volt to drive because it have 3 LED per one segment.All segment no need to scan display. Source code programming with CCS C Compiler availible.
2.3 ” Digital thermometer – [Link]
This is an example that demonstration how to control some devices via USB interface.The PC software program with delphi.
– CPU PIC18F4550 with full speed USB interface at 48MHz.
– USB 2.0 compliance
– Use on-chip USB driver
– Control 1 stepping motor.
– MPLAB C18 for firmware at USB devices side.
– Delphi 6 for PC Host software.
Control stepping motor via USB interface – [Link]
The efergy meter is a wireless smart electricity meter that helps you track how much energy you use encouraging a reduction in energy while saving money, because the monitor gives instantly an accurate reading of how much energy you are consuming.
Efergy tells you every 6 seconds how much power you are consuming, how much money this is costing you and an estimate of your personal contribution to the climate change. If you turn a set of lights ON or OFF, you can see INSTANTLY the change this has to your energy use. Once you have this information to hand means you, your family, or business, can visually see the benefits of saving energy.
Efergy: Home energy meter – [Link]
Ever feel inundated by your IM client? The “Slow Messenger” is a small 96 x 64 pixel OLED display that delivers your instant messages over a long period of time and depending on your attachment to the device, gives you more or less messages. The device is meant to teach us about how much personal messaging means to us. If you leave the device alone for instance, it would not give you any messages. Hmm… this sounds like the same way my real IM client works.
Slow Messenger makes you care more about instant messaging – [Link]
I’ve had a few scuffles in my house over the TV remote so I decided to do something about it. I built a circuit that will block my TV and any device I choose from getting a signal from the normal remote control. I turn an ordinary remote into a jammer and the remote still works normally! Watch the video to see it work.
TV Remote Jammer! – [Link]
Control your home thermostat from work. Turn on a sprinkler from anywhere in the world by flicking a switch. This Instructable shows how to link two or more $4 microcontrollers using the backbone of the internet and some simple VB.Net code.
This builds on an earlier Instructable which shows how to link a microcontroller to a PC and use a pot to control a servo. This time we have a microcontoller talking to a VB.Net program then to an ftp website, back to another VB.Net program and thence a second microcontroller anywhere in the world, with or without human intervention.
Worldwide microcontroller link for under $20 – [Link]
This Instructable shows you how to interface a PC and microcontroller. This demo will sense the value of a pot or any analog input and also control a servo. Total cost is under $40 including the servo. The servo turns on a microswitch and then the microswitch turns on a lamp. In a practical application the pot could be a temperature sensor and the servo could be turning on a heater. The servo could be replaced with a relay or other power controller. The picaxe is programmed in a simplified version of basic and the interface uses VB.Net. All software is available for free.
Control real world devices with your PC – [Link]
Rob writes in –
Sometimes the best way to take a step forward is to take a step back in time. So Andrew Smith designed a fully-functional toy oscilloscope, made out of parts he found in his junk box, such as the EF91, EF80 and EF184 valves. Using a DC-DC converter to power the old (but still working) 7cm CRT he discovered in his loft, Andrew housed it in the same wooden box as the rest of the circuitry. The whole system runs from a single regulated 12.6V DC supply, which can be derived from a “wall-wart” PSU. Doc Brown would be proud.
Toy Oscilloscope – [Link]
Serasidis writes in –
An RC5 infrared remote control receiver that can be used to handle any function or software installed in your Media Center PC. Further, it can be used to power On/Off your Media Center even it is in Hibernate, stand-by or power-off mode.
Infrared remote control receiver for Media Centers – [Link]