lcd

[aamir1]

Hi guyz is there any way to change the line of lcd by sending some data i want to change the line via ascii coe not by sending the cursor position command please reply

 

[Ian Rogers]

You want to change a line of characters WITHOUT changing the cursor position..
Can you give us a bit more to go on!!

 

[aamir1]

i mean i want to write in first line then in 2nd line but i want to change the line using a an ascii code not a command such as we can give space by using an ascii code 20h the same way i want to change the line using an ascii code can it be done?

 

[Ian Rogers]

No!! I'f you are talking about a alphanumeric screen then the address is 0x80 for the top and 0xC0 for the bottom ( assuming a 16x2 ) If you however keep writing blanks it will eventually start writing on the second line..

What's the problem with sending a command character first?

 

[aamir1]

actually i want to send data again and again i want to use dptr register for that i want to send all the data with one routine but it is only possible when i can change the line with ascii code not with command is there any way out?

 

[Ian Rogers]

If you make your routine to include the command, it should work.
You only need to send the first byte as a command then the rest as data.. Or get a serial back pack so you can do it all with ASCII..

 

[aamir1]

what is serial back pack ?

 

[Ian Rogers]

Its a small PIC or AVR, connected to the LCD so you can automate the commands serially.

Here's one. https://www.proto-pic.co.uk/content/datasheets/SerLCD_V2_5-Datasheet.PDF

 

[aamir1]

ONE MORE thing im currently trying to make a program for a hardware actually its controller is burnt i have to control 20 inputs through opto coupler since input is of 24V coupler is changing level to 5V for uC but the problem is the hardware of coupler is ihave mentioned in the picture the collector is directly connected to port and because of that there is always 0V on the pin so how can i detect the input via controller ??

 

[Ian Rogers]

You need to put a pullup on the uC pin a 10k resistor from the pin to 5v

 

[aamir1]

means i should place a 10K resistor at the collector of coupler and the other end to VCC?

 

[Ian Rogers]

Yes! Then the uC will see high and low...