Ethernet has traditionally been a quite complex interface. All Ethernet chips until today had 100 pins or more, where difficult to find in small quantities and difficult to use from a small microcontroller with little memory. Microchip has changed the world with their new ENC28J60 Ethernet chip! This opens a whole world of completely new applicati
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ons. You can easily build small devices which can be spread all over the house and simply connected to ethernet. The ENC28J60 from Microchip is a fantastic chip. It has Tx/Rx, MAC and PHY in one small chip. There are very few external parts. Basically just a crystal and an Ethernet transformer, aka magnetics. All this comes in an convenient 28-pin DIP package. Easy to solder and perfect for hobby applications. The microcontroller can then control any hardware you like: You can attach some sensor (light, temperature), you can switch on an off something you can attach a LCD display, etc. In this first article we will build a generic hardware with lots of IO interfaces and analog to digital converter inputs. We will however only control a small relay to switch on or off something. In later articles we can then use the same hardware and do more complicated things. The main purpose is to show here the circuit diagram and explain the software. We use a UDP application to send commands to the microcontroller. Those commands will then cause the microcontroller to switch on or off the relay. It think it will be possible to even implement TCP. The current UDP software is less than 3k bytes and that is not even half of the memory on an Atmega88. TCP would then allow us to control the device via a web browser. I have however not tried it yet. Here is the circuit diagram. Most of it is very straight forward and standard for the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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