5.3. Gets Data ADC - Serial Port

In this experiment we will show you how easy to transfer data serially. In this experiment we used a converter serial to parallel that we build up by using microcontroller chip. Data will be transfered serially from ADC board to Personal computer, as shown in picture bellow.

Delphi Programming ( Download file ex513.zip )

a. Puts 1 Edit Components, 1 Timer and label on Form, as shown in picture bellow. Configure Object Inspector for Timer1 as Enabled = True, Interval = 1000 ms, as shown in the picture bellow

const
base = $3f8;{base address port serial}
lcr = 3; {line control register}
dll = 0; {divisor lacht low byte}
dlh = 1; {divisor lacht high byte}
lsr = 5; {line status register}

implementation

{$R *.DFM}

procedure TP2S.FormCreate(Sender: TObject);
begin
 asm
  mov dx,base+lcr; {address line control register}
  mov al,$80 ; {10000000b = access bit divisor lacht}
  out dx,al
;
  mov dx,base+dll; {address divisor lacht low byte}
  mov al,$30 ; {DLLB = 30h}
  out dx,al
;
  mov dx,base+dlh; {address divisor lacht high byte}
  mov al,$00 ; {DLLH = 00h}
  out dx,al
; {In this case Port serial has a baud rate = 2400 bps}
  mov dx,base+lcr;{address line control register}
  mov al,$03 ; {00000011b =}
  out dx,al ; {bit 7=0, access to Rx buffer & Tx
; {bit 6=0, set break disable
; {bit 5-4-3=000, no parity
; {bit 2=0, one stop bit
; {bit 1-0=11,data lenght 8 bit}
 end;
end;
Procedure Receive_Data_Serial;
begin
 asm
  mov dx,base
  in al,dx
  mov data,al
 end
end;
Procedure Initserial;
begin
 asm
  mov dx,base+lcr; {address line control register}
  mov al,$80 ; {10000000b = access bit divisor lacht}
  out dx,al
;
  mov dx,base+dll; {address divisor lacht low byte}
  mov al,$30 ; {DLLB = 30h}
  out dx,al
;
  mov dx,base+dlh; {address divisor lacht high byte}
  mov al,$00 ; {DLLH = 00h}
  out dx,al
; {Pada saat ini Port serial}
; {memp.baud rate = 2400 bps}
  mov dx,base+lcr;{address line control register}
  mov al,$03 ; {00000011b =}
  out dx,al ; {bit 7=0, access to Rx buffer & Tx
; {bit 6=0, set break disable
; {bit 5-4-3=000, no parity
; {bit 2=0, one stop bit
; {bit 1-0=11,data lenght 8 bit}
 end;
end;
procedure TP2S.Button1Click(Sender: TObject);
begin
 initserial;
 timer1.enabled:=true;
end;
procedure TP2S.Timer1Timer(Sender: TObject);
begin
 Repeat
  asm
   mov dx,base+lsr; { address line status register }
   in al,dx
   and al,$01 ; {LSR = 00000001b, deteksi bit 0}
   mov status,al ; {bit 0 = data ready}
  end;
 until status = $01 ;{ jika bit 0 = 1 then data ready}
 Receive_Data_Serial;
 edit1.text:=inttostr(data);
end;

c. To run the program, you can hits F9 or RUN menu, and then you will show a picture as shown bellow, and try to simulate the program by writing a data on edit1 with range value 0 .. 255 in decimal.

Free Software
Delphi

Lesson 1
Delphi Programming
1.1. IDE Delphi
1.2. Component

Lesson 2
Printer Port / LPT
1.1.Basic
1.2.Address
1.3.Port Register
1.4.8 Bit Data Input
1.5.Test Circuitry
1.6.Assignment

Lesson 3
Printer Port / LPT
Experiments
3.1.LED
3.2.Swicht
3.3.Motor Stepper
3.4.DAC
3.5.ADC
3.6.Graph Display

Lesson 4
Serial Port
4.1.Basic
4.2.Hardware
4.3.Port Register

Lesson 5
Serial Port Experiments
5.1.LED
5.2.Stepper Motor
5.3.Swicht
5.4.ADC

Lesson 6
Game Port
Joy Stick
6.1. Basic
6.2. Experiments