Here is an example which implements a clock in just 36 lines of perl code. It displays time and date and the upper right corner shows a little icon called `heartbeat`. The `heartbeat` is added by the LCDd server. This `heartbeat` icon blinks once in a while to indicate that the display is still alive. In lcdproc you can have more than just strings.
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You get bar-graphs, scrollers, title bars. and text strings. At the beginning of the program you define those objects (they are called widgets) and then you fill them with data. It`s explained in the LCDproc Developer`s Guide from page 7 and on wards. #!/usr/bin/perl -w. # initiate the communication: print $remote "hello
";. # set our name and define a text string widget print $remote "client_set name lcdtime
"; print $remote "screen_add scr1
"; print $remote "widget_add scr1 str1 string
";. while(1) {. $date = scalar localtime; # now write to the LCD: print $remote "widget_set scr1 str1 1 1 "$date"
"; sleep 10; } The parallel port of a PC works according to specifications with 5V. If you now take a look at the datasheet of a modern LCD display (e. g from tuxgraphics: ) you will notice that even though the displays are big they need extremely little power. Only 2 mA ! With so little current it must be possible to power the display directly from the parallel port. The advantage is then that you do not need any extra power connector. It is just one LCD display with one connector to the parallel port. Very convenient. It is possible with a parallel port that really provides 5V. The problem is that there are some which do not follow the specifications. So how do you know if your parallel port is good enough for "self powered" solution Here is a little test: Now connect a 33K resistor to the parallel port between pin 1 and pin...
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....
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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....
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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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