Do we need to blank the LCD screen everytime we want to display new data?

hi
do we need to blank the lcd screen everytime we want to display new data or does it get overwritten on the previous location.(since only a part of my lcd message needs to be updated regularly).

Re: lcd doubt


clear it first

lcd doubt

Similar to a clock with calendar? I would only overwrite the part I wish to change, that way I'm not spending CPU cycles doing needless work. Granted there will be a brief "smear" when both characters appear in the same location because dark is faster than light with LCDs.

lcd doubt

I agree with ldanielrosa

lcd doubt

get the data sheet of the lcd....it will have the adress of the pixels or locations(character locations)....next time u wanna write something without disturbing the rest of the data ...bring ur lcd cursor to that location ...and write the data.....the lcd data sheet has the information fr moving the cursor
fr more info go here...it will give u ready to use programs...to do ur data manipulation...
h**p://mcu-programming.blogspot.com/search/label/LCD

cheers!!!

lcd doubt

steps are:

initialize
clear
send data
clear
send data
.
.
.
.

Re: lcd doubt

Assuming that you are using 16*2 charector LCD using Hitach lcd driver built in.

Initialise LCD using the command sequence described in datatsheet.
then send 01 as command -lcd cleared and cursor on position 1 of line1

If you enabled auto incriment position during initialisation it is easy to update.

when you want to update some part of data position cursor at the start of string.

cursor can be positioned by sending numbers 80h to 8Fh for uppar line and C0h to CFh on second line.
ie if you want to start from 4 th location in first line send 83h ,cursor comes to 4 th position.Then send 'A' 'B' etc in data mode.

need not clear lcd if you dont want to change the entire screen.


Also in case you apply 01 command ie clear screen, allow 1ms delay as it is a lengthy command.

hope this helps.

if you want i can provide initialisation or any routines which I have .

picstudent

lcd doubt

For me I will overwrite it. If my message it to short I will insert it will 0x20h