[SOLVED] Intercept lcd module data

[fer_yana]

I have a project to intercept data send to lcd module.Can lcd module data be intercepted?

 

[thunderboympm]

which micro controller are you using.
What data to be intercepted
Explain your problem a little bit more

 

[fer_yana]

I used atmel at89c55wd and i want to intercept data bus db1-db7 from lcd module.

 

[alexxx]

i want to intercept data bus db1-db7 from lcd module.

What do you mean by that? You want to cut these cables? You are using simulator, bread board or printed board? Or maybe you want to block these data from the program? Please explain clear what you are trying to do.

 

[fer_yana]

i want to read data send from other microcontroller.

 

[alexxx]

i want to read data send from other microcontroller.

OK then. Wire those 8 signals to 8 pins of your MCU and read them. You could connect them to 8 interrupt pins, so that you are instantly updated when a pin change occurs. So yes, it could be done, although I can hardly think of a purpose to do so...

 

[fer_yana]

lcd module used graphical lcd. can be intercepted? And how to synchronize. Or i just scan into 8 pins?

 

[alexxx]

lcd module used graphical lcd. can be intercepted? And how to synchronize. Or i just scan into 8 pins?

No need to intercept, scan 8 pins. You could poll them through the program, or use interrupts to automatically update their status.

 

[fer_yana]

can you give me some code example so i can learn?

 

[alexxx]

can you give me some code example so i can learn?

Sorry, I don't use your controller.

 

[fer_yana]

if this project done using your controller. Can you give me code example. I will analize your code and then convert into mine. You can used assembly,basic,c, or pascal.

 

[alexxx]

if this project done using your controller. Can you give me code example. I will analize your code and then convert into mine. You can used assembly,basic,c, or pascal.

Sure, let's assume I read the status through PORTA. DB0 goes to PORTA0, ...., and DB7 goes to PORTA7. This is code for AVR.

void main (void)
{
  volatile unsigned char status;  //variable to store the status of the lcd pins
  DDRA = 0;  //make PORTA input to read those pins
  while (1)
  {
    status = PINA;  //Read PORTA (that is read lcd pins) on status variable
  }
}

So status variable is constantly updated from PORTA which reads lcd pins.

Hope this helps.

 

[fer_yana]

Thanks alexx, i will try to simulate first before i made prototipe board.

---------- Post added at 20:15 ---------- Previous post was at 18:53 ----------

i have try to simulate your code using proteus. It only display value FF. This is my code:



var Result:byte;
P1:=255; // port1 as input
While true do begin
Result:=P1;
End;

 

[alexxx]

i have try to simulate your code using proteus. It only display value FF. This is my code:

var Result:byte;
P1:=255; // port1 as input
While true do begin
Result:=P1;
End;

If the lines you are reading are constantly in '1' state, then it wouldn't suprise me.
Since you don't provide any schematic, only assumptions could be made.
By the way, it is the first post I see about real time programming written in Pascal. :smile:

 

[fer_yana]

Sorry for late reply. This is my schematic. I want to intercept data from LCD2 and displays on LCD1 (4 bit example).

Can you give an example code to intercept data?

 

[fer_yana]

Sorry i replace schematic for better view.

 

[bjuric]

You also need to monitor RS and E lines.
RS will tell you what is being sent to the LCD (data or command).
LCD latches data from port on falling edge on the E line. When you detect falling edge on E line (poll or interrupt on falling edge), then copy the data.

 

[fer_yana]

How to copy data? I have tried to monitor pin D4-D7, i cant poll data from it. Can you give me example code?

 

[tushki7]

Hello ,
If you just want to show data on another lcd then i dont understand why you are going this way?? :shock: why adding another microcontroller and intercept the data(D0-D7, en, rs & rw pins of lcd??) :arrow:
just put another lcd with pull up resistors in parallel to previous lcd!!! Here you go both lcd's showing the same data !!! :?:

 

[fer_yana]

no, schematic only for example. The real one is i want to intercept data from lcd on different microcontroller (machnine lcd module). I have counting machine, i want to intercept data from lcd on the machine. Then send result to computer.