Skip to main content

Serial Communication

RS232 for serial communication

Serial Communication
If any data parallel port with certain bit is sent simultaneously at one click, data serial port is sent one by one per one bit. The weakness of sending data by serial is that it is more complex rather than by interface parallel port. It is because the data is sent per bit in series, so that the data sending occurs slowly. Nevertheless, this condition can be overcome by high Bard Rate on data sending. Meanwhile, the strengths are:
1.      Cable for serial communication can be longer than parallel, the data in serial communication is sent for logic ‘1’ as tension -3 to -25 volt and for logic ‘0’ as tension +3 to +25 volt. Therefore, the tension in serial communication has maximum tension handle 50 volt. Whereas in parallel communication, it is only 5 volt. This case causes disturbance on long cables which is easier to overcome than parallel one.
2.      The number of serial cable needed is less than parallel one. You can connect two sets of computer equipment with only three cables to configure null modem, TxD (sending channel), RxD (receiving channel) and ground. Imagine! If it uses parallel technique, there will be 20-15 cables! However, in each computer with serial has to spend much more cost, for interface serial is more expensive than parallel one.
3.      Almost all equipments (palmtop, organizer, mobile phone, etc) recently use infra-red technology for data communication. In this context, data sending is conducted by serial IrDA-1 (the first infra-red specification) is able to send data in 115,2 kbps in speed and it is assisted by UART equipment. The charge length decrease 3/16 from standard RS-232 to economize the power
4.      For embadded system technology, there are a lot of microcontrollers completed with serial communication (both RISC and CISC) or serial communication interface (SCI). With the existing of integrated SCI on IC microcontroller, it will decrease the number of an output pin. Furthermore, it only needs 2 main pins : TxD and RxD (out of ground reference)
Data frame on sending serial data AVR AT mega 16 can be viewed through the picture below:
Picture. The Frame of Sending Serial Data for Letter A
In the condition without data (idle), signal is in a high logic. When data is started to send, it will begin by giving start bit signal (St) with low logic as initial sign of data sending, followed by data that is sent (5, 6, 7, 8, or 9 bit). Bit parity has optional character. At last, it is added by stop bit (Sb) which is 1 or 2 bit in number.
Additional Note:
Serial communication between PC and microcontroller can not occur direct by connecting pin Tx on PC with pin Rx on microcontroller and Rx on PC with pin Tx on microcontroller, and pin ground on PC with pin ground on microcontroller.

The level of work tension on serial communication on microcontroller is TTL (0-5 volt). Meanwhile, the level of work tension in PC serial port is from +15 V to -15 V. It happens because there is difference between tension level used for PC serial communication and microcontroller. The level of serial communication tension on microcontroller has to be adjusted with the level of serial communication tension on PC. To do that, it needs the series of converter RS 232. The series picture can be seen as follows:
Picture. Schematic of Converter Series RS 232

Popular posts from this blog

Login Form Delphi by Connecting to Ms Access Database.

this the step by step  to making application :

Login Form Delphi by Connecting Ms Access Database.

In making/ building application in Delphi, login Form is an important to protect application so that cannot be open by irresponsible person. This login Form is connected with database so that able to keep a lot of username data and password. Before make the application, please create a database as the picture below:
Picture :Login  form Delphi database Microsoft Access
Save the database in the folder which use to save the application

Next step is create the application

Enter the component and the source code as follows.

No Component NameProperties Value1Label1CaptionUsername2Label2CaptionPassword3Edit1Text -4Edit2Text -5Button1CaptionLogin6Adoconnection1--7AdoQuery1ConnectionADOConnection1

Arrange the component as the picture below:

Figure. Login Form Delphi design form

 Create new form

Form properties can be check in the table below
No Component NameProperties Value1Form1CaptionSuccess…

Step by step Accessing SMS With Delphi: Sending SMS Using Borland Delphi 7 Exploit Comport Component (Siemens))

In this example, will present the way how making SMS delivery program with Delphi, basically, data in data communication series between Delphi and mobile phone happen in Format Protocol Data Unit (PDU). The destination number of sending Message and message that will be sent through Delphi program that is made have to be changed into PDU Form first, next is the data will be sent through serial port to mobile phone. To make the send SMS Application , please enter the following component to Form 1.

No Component NameProperties ValueButton1CaptionConnectButton2CaptionDisConnectButton3CaptionConvert to PDUButton4CaptionSend to HPButton5CaptionClearButton6CaptionStart Send SMSButton7CaptionSet PortEdit1Text-Edit2Text<Type The SMS here>Edit3Text-Label1Caption1) Destination Number :Label2Caption2Label3CaptionPDU lengthLabel4CaptionLabel lengthComLed1--Memo1--Memo2--Comport1--Arrange the Component  in such away so that the visualization program is as follows:

Then type the follow…

The Example Using Chart In Borland Delphi 7

The Example Using Chart In Borland Delphi 7

In this writing will discuss about how to use the chart in Delphi 7. In the example that is made by using Delphi 7, chart will appear 2 data in the form of incremental data number, the first data named data 1 and the second data named data 2. Data 1 is incremental data 1 that is begun from 0 until 10; while data 2 is same. Yet, in the beginning condition of data 1 start from 0 while data 2 start from 1.

To make application as the explanation above, please enter the components in the table below into design form.

NoComponentPropertiesValueNote1Form1CaptionThe Chart of Data on Delphi 72GroupBox1CaptionThe Chart of Data on Delphi 73Label1CaptionData 14Label2CaptionData 25Edit1Text06Edit2Text07Button1CaptionShow to Chart8Button2CaptionClose9Timer1EnabledFalse10Chart--Check the NoteNote:

Double click on chart component, set the property of chart as below:

Click on  Add.. Button

Then the following chart gallery will be shown:

Choose the…