Writing LEDs air
Today, most electronic systems with complex functions, micro-controllers are designed using. Easily programlanabilmeleri, prices to be cheaper and less due to external hardware requirements microcontrollers have an important place in the field of electronics. For example, Series produced by the company Microchip PIC microcontrollers, is one of the most preferred in the market of integrated, programmable. Bu entegreler 8, 18, 28 or 40 produced, many types of legs.
16F8X series of these PIC microcontrollers, 18 and flash memory technology has legs. Thanks to this technology, and can be removed easily integrated to integrated re-installed program can be programmed at any time. 13 One input-output port (Port A Port B ve) Not enough for most applications. Integrated in assembly language for programming, as well as high-level languages such as BASIC or C can also be used. PIC microcontrollers are many books on the market. Detailed information can be learned from these books .
In this article,, From PIC16F84A microcontroller and 8 writing up the construction of an electronic circuit using LEDs is described. With this circuit 8-10 of characters that can be created with any text in the air.
Circuit diagram as shown in Figure 1 PIC16F84A micro-controller port B outputs 8 number LED and resistors connected. 422pF’lık MHz crystal and oscillator circuit consisting of two condenser produces clock pulses required for the operation of the PIC. Supply circuit is provided with a 9V battery and a 5V regulator circuit.
- 1 One PIC16F84A microcontroller
- 1 One LM7805 voltage regulator
- 1 took 4MHz crystal
- 1 adet buton
- 1 One key
- 1 aThe 100nF kondansatör
- 2 aThe 22pF kondansatör
- 1 adet 4.7k direnç
- 1 adet 1N4148 diyot
- 8 ADET Parlak Mavi LED
- 8 number 100 ohm direnç
- 1 One 9V battery, and the battery cap
- Copper plate or perforated phenolic
The logic is
Operation of the circuit is based on the principle of illusion. As we know, the eye, recognizes and repeats periodically repeated events, such as the time between durağanmış short enough not to realize the impact of the flicker. For example 1 second 50 A flashing light on fire, gives the impression of a continuous time. Likewise television motion of the picture of the frame repetition frequency is selected high enough continuously detected. Feature of the error of the eye, LED provides up into the air with a few pieces of writing.
Equipped electronic circuit shown in Figure 1, although a fairly simple circuit must be installed in order to run a program the PIC microcontroller. The job of the loaded program, based on the characters printed on the air 8 One LED is lit and put out all about setting a schedule. After you install the program correctly PIC LEDs quickly moved to the right-to-left text is provided in the air the formation of. Briefly, The logic of operation of the system, Sent to the PIC 8 at which time the LED stays on with columns of bits which can be summarized as set.
Before writing the program to write letters in the air (or character) need to be made through the column by. To do this, I need to make a few drawings on paper. For example in figure 2, A, B, C to form letters 8 Depending on the time step should be lit LEDs showing which.
Each letter is illustrated in, 8 rows and 5 consists of columns. Letters between 1 column is empty. According to this logic into the air 8 writing letters to a total of 48 pieces of information needed by the column. So the PIC microcontroller 48 One column information in time
intervals must be programmed to send port.
Figure 3 shows in detail how the information is obtained from the column. For example, a letter needs to be done to get the column information, Instead of off-state LEDs 0 figure, LEDs are lit as a substitute for 1 figure consists of writing. In this case, for each column 0 and consisting of 1s 8 bit number is obtained.
This number of 16 (hexadesimal) data is written to the base column is obtained. For example, the letter A in the first column 8 bit 11111100 0xFC’dir for the base number of 16. In the same way in the last column 00000000 for the base number of 16 is 00 or 0 ×. Here, at the base 0x symbol indicates that the number of 16. In this way, information can be easily obtained all the letters column for.
For more detail: Text in the air with PIC16F84