I recently purchased 10 SLM1608 (SLM1606) LED matrix display units from Ebay (you might also contact the seller directly at [email protected]). These are 16x16 LED matrix units with a green and a red LED per pixel allowing each pixel to be switched to either green, red, amber or off. The goal of this LEDMATRIX project was to build a 80x32 pixel display by arranging the displays in two rows with 5 displays each giving a total of 16*16*2*2*5 = 5120 LEDs to be controlled individually. Fortunately these displays come with interated controllers and the data can be shifted into a single display using as few as 6 digital signals. By multiplexing some of the select signals all 10 displays can be controlled with a total of ten wires. Using a cheap ATmega32 microcontroller all ten displays can easily be controlled and updated in real time.
Click here to download the full size of the above Circuit.
This kind of display is usually controlled via RS232. This has the disadvantage of being very slow and the display data is limited to simple text messages only with the microcontroller of the display doing the actual text drawing. Instead of doing it the same way i decided to use an ethernet interface for the LEDMATRIX display. Even the most simple ethernet interface i am using is fast enough to transfer graphics data in realtime from a PC to the display allowing to update the entire screen 50 times a second. The ethernet support of LEDMATRIX is based on the cirrus logic cs8900 chip which is e.g. supported by the free Procyon AVRlib which has been used for this project.
The LEDMATRIX additionally includes a simple speaker allowing to e.g. notify the user of a new message being displayed. Furthermore a TSOP1736 IR receiver can optionally be connected. This device receives and decodes the IR signals used by ordinary TV remote controls. By returning informtion about received IR signals to the controlling PC, the displays contents may e.g. be remotely changed using a simple spare IR remote control.
With one display drawing 2A @ 5V, the power supply of the LEDMATRIX needs to source all ten displays and thus needs to be able to provide a total current of 20A. You might be able to find a cheap old PC power supply that delivers 20A on the 5V line. I am using a Lambda UAZ1G 30A power supply. I made some small modifications to...
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.....
characters left: