Circuit Diagram Knowledge

Microcontroller AT89C2051 is a 20 pin version of the microcontroller AT89C51. Technical interface to microcontroller AT89C51 AT89C2051 and can be prepared very simply. SED 1200 LCD can be used to display 20 letters / numbers very good, quite adequate for displaying telephone numbers and other short message message. As the LCD display in general, SED1200 consists of two parts, namely the LCD panel which consist of many points LCD and a microcontroller attached to the panel and serves to set the dots LCDd be the letters / numbers that read, as well as functions for communication between the LCD display with another microcontroller using the LCD display. Task LCD display microcontroller users only send ASCII codes to be displayed.

In the data sheet says SED1200 LCD display is compatible with 4-bit microprocessor and 8 bits, this is due to SED1200 only equipped with 4 channels of data (DB0 .. db3) is used to distribute the ASCII code or command to set its SED1200. In terms of ASCII codes and commands are all 8-bit codes, the codes were sent twice, which first shipped is 4 bits are weighted higher (most significant bit - D4 .. D7) and then the remaining 4 bits (D0. . D3). In addition to DB0 .. db3, SED1200 also equipped with CS, WR and A0 such as components that are compatible with the microprocessor, which is somewhat distorted signal CLK lajut which will be discussed further below.

A0 is used to distinguish data that is sent to the SED1200, if A0 = 0 data sent is a command to control the SED1200 and vice versa if A0 = 1 data sent is ASCII code you want to display.

The process of sending data to the SED1200 depicted in Figure 1 can be described as follows:

CS signal is used to activate the process of sending this data, during this process CS activated by voltage level 0 .

The data will be sent to the SED1200 prepared at DB0 .. db3, as discussed above codes are sent to the SED1200 split into 2 time delivery, this is seen clearly in Figure 1 which describes the delivery of D4 .. D7 .. D0 and subsequent delivery D3.

After the data is ready, WR signal is used as a signal of commando for the SED1200 to retrieve the data on DB0 .. db3. Data collection is exactly what happened at the time of WR changed from 0 to 1

Interface to AT89C2051

AT89C51 AT89C2051 is a simplified into a microcontroller which only the legs of 20, a simplification that resulted AT89C2051 not have the legs DB0 .. DB7, P2.0 .. P27, WR, RD and ALE and how many other feet, other than that the instruction MOVX @ DPTR, A can not be used, thus the circuit of Figure 2 at all can not be used for the AT89C2051, and instead made the circuit of Figure 3, in this series and WR DB0 .. db3 replaced with Port 1 and its function is simulated through the program.

SED1200 CLK foot foot connected with P1.7 AT89C2051, SED1200 pulses required to process the received data generated by the program, it is not necessary to provide a special circuit to generate clock.

Cuts Program 2 is a sub-routine to control the SED1200 are connected to the AT89C2051 as shown in Figure 3, before taking the second sub-routine, the data to be sent to the SED1200 had to be prepared in the accumulator A.

Differences sub-routine and KirimASCII KirimPerintah lies in the value A0 at the time of the sub-routine work. Sub-routine KirimPerintah work with A0 = 0 (line 7), AT89C2051 received data sent as a command to set the SED1200 SED1200 work. Sub-routine KirimASCII work with A0 = 1 (line 11), received the data sent AT89C2051 SED1200 as ASCII code to be displayed

Throughout the process activated by the CS data transmission voltage level 0 is done in line 13 and in his re-nonaktip on line 19.

Data in the accumulator A is sent byte-by-half-byte half twice, first sent A4 .. A7 (lines 15 and 16) then sent A0 .. A3 (lines 17 and 18).

Given AT89C2051 no ALE signal instead row 22 to be raised 16 to 25 clock pulses required by the CLK SED1200. 16 pulse is generated after A.0 .. A.3 sent to the SED1200, out of the sub-routine is SED1200 is ready to receive data again.

Line 29 to 36 Discount Program 2 simulates line 21 Discount Program 1, in line 29 feet WR SED1200 in zero out, lines 30 to 35 send to DB0 A0 .. A3 .. db3 (P1.0 .. P1.3) without changing the other signals are already in Port 1. In line 36 WR returned to 1 , then that information on DB0 .. db3 taken by SED1200.

Treatment LCD Monitor. At this time computer use familiar and already widely used either for work or entertainment. And of course when talking about computers it will not be far away with a device called a monitor. And today use CRT monitors have started to decrease with the LCD Monitor that despite having a price that is quite expensive but have many advantages than conventional CRT monitors.

Here are a few advantages of LCD monitor is a stylish design, flat Lcd and a brighter color than convex or crt monitor Lcd, while also LCD Monitors have many advantages among which have a high resolution so that it can help many people especially those working Visual design field.

There are some special treatment for LCD monitors in this case is for the treatment of LCD monitors, the following are some steps steps:

Use the LCD as needed, Do not use if you do not need so-necessary and do not use it 24 hours nonstop jedanya have no time for any electronic item there during his lifetime (Lifetime). Turn off your LCD monitor when your computer dies, in order to save electricity and also keeps your LCD monitor remain durable.

Use the type that has a grounding electrical power, because it can minimize the damage in the event of lightning strikes. This option is optional.

Perform regular cleaning, at least 2 weeks 1 times, for LCD monitors are always in a state clear of dust and other debris. Remember! to clean it must use a very soft cloth that has spread with a special liquid cleaners LCD monitor. If necessary you can buy special equipment to clean the LCD monitor.

Do not engage in cleanup activities in the state of electricity is still flowing, unplug all cables available on the LCD to avoid things that are not desired. The existence of water coming into the series of LCD monitors will be able to cause fatal damage.

Keep the LCD of the things that contain water such as rain water, drinking water etc.. Because all electronic goods electrical short circuit will occur if water enters into the electronic components.

Keep the LCD of goods containing such magnetic sound system, Persani, HP etc. signals. Because it will be fatal is going to happen Noise or damage which may destroy the layout on the monitor Lcd.

LCD Save a strategic place and safe from the reach of small children, so that you can not avoid tersenggol LCD or a small toy.

Unplug all cables associated with the computer (including LCD) in the event of rain accompanied by lightning, because lightning can be grabbed via the antenna propagate through the cable TV and electricity.

To protect the Lcd / LCD Lcd can use the Screen Protector function prevents dust entry into the LCD and also take care of all sorts of scrapes. Remember to choose the Lcd protector is not a trace when reopened.

If there is damage to your LCD monitors, LCD submit to the experts. Do not disassemble itself without accompanied by experts in the field of electronics. Module Components including LCD monitors that can be easily damaged. LCD Monitor Service you to the service center to ensure the improvement is good and right.

Good article on the LCD monitor is beneficial treatment.