Commands and Instruction set

Only the instruction register (IR) and the data register (DR) of the LCD can be controlled by the MCU. Before starting the internal operation of the LCD, control information is temporarily stored into these registers to allow interfacing with various MCUs, which operate at different speeds, or various peripheral control devices. The internal operation of the LCD is determined by signals sent from the MCU. These signals, which include register selection signal (RS), read/write signal (R/W), and the data bus (DB0 to DB7), make up the LCD instructions (Table 3). There are four categories of instructions that:


  • Designate LCD functions, such as display format, data length, etc.
  • Set internal RAM addresses
  • Perform data transfer with internal RAM
  • Perform miscellaneous functions



Table 3: Command and Instruction set for LCD type HD44780


Although looking at the table you can make your own commands and test them. Below is a breif list of useful commands which are used frequently while working on the LCD.


No. Instruction Hex Decimal
1Function Set: 8-bit, 1 Line, 5x7 Dots0x3048
2Function Set: 8-bit, 2 Line, 5x7 Dots0x3856
3Function Set: 4-bit, 1 Line, 5x7 Dots0x2032
4Function Set: 4-bit, 2 Line, 5x7 Dots0x2840
5Entry Mode0x066
6Display off Cursor off
(clearing display without clearing DDRAM content)
0x088
7Display on Cursor on0x0E14
8Display on Cursor off0x0C12
9Display on Cursor blinking0x0F15
10Shift entire display left0x1824
11Shift entire display right0x1C30
12Move cursor left by one character0x1016
13Move cursor right by one character0x1420
14Clear Display (also clear DDRAM content)0x011
15Set DDRAM address or coursor position on display0x80 + address*128 + address*
16Set CGRAM address or set pointer to CGRAM location0x40 + address**64 + address**
Table 4: Frequently used commands and instructions for LCD
* DDRAM address given in LCD basics section see Figure 2,3,4
** CGRAM address from 0x00 to 0x3F, 0x00 to 0x07 for char1 and so on..

The table above will help you while writing programs for LCD. But after you are done testing with the table 4, i recommend you to use table 3 to get more grip on working with LCD and trying your own commands. In the next section of the tutorial we will see the initialization with some of the coding examples in C as well as assembly.

Share it! Like it!

Forum Activity
majoka Avatar
Posted By majoka
Wed Jul 30 2014, 02:45 PM
@ sermeteraythank you for sharing your experience ...
majoka Avatar
Posted By majoka
Wed Jul 30 2014, 02:38 PM
@ Peter_ParkerHC06 by default baud rate is 9600try...
majoka Avatar
Posted By majoka
Wed Jul 30 2014, 02:25 PM
attach is the code for lcd may be need a little ch...
majoka Avatar
Posted By majoka
Wed Jul 30 2014, 02:21 PM
@ pravin_35both compilers are almost sameif you ha...
pravin_35 Avatar
Posted By pravin_35
Wed Jul 30 2014, 07:38 AM
http://extremeelectronics.co.in/pic16f877a-tutoria...
NexusRevZ Avatar
Posted By NexusRevZ
Wed Jul 30 2014, 02:31 AM
Ok, I have edited the code, it's updated above wit...
NexusRevZ Avatar
Posted By NexusRevZ
Wed Jul 30 2014, 02:10 AM
Oh tahnk you so much for the reply. I will do imme...
ajay_bhargav Avatar
Posted By ajay_bhargav
Wed Jul 30 2014, 01:56 AM
You cannot move and read data from EEPROM immediat...
pravin_35 Avatar
Posted By pravin_35
Wed Jul 30 2014, 12:39 AM
Remove all power connections to the circuit at the...
NexusRevZ Avatar
Posted By NexusRevZ
Tue Jul 29 2014, 09:31 PM
This simple code is test the write and read of EEP...

Conversation

NexusRevZ
Tue Jul 29 2014, 09:32 PM
Anyone good in Asm lang?
ajay_bhargav
Mon Jul 28 2014, 12:34 AM
@ Anshu Raj sorry we do not take such requests.
Sun Jul 27 2014, 12:23 AM
Anshu Raj
sir plz send the automatic collage alram bells in 2 hrs bells ring. For microcontroller programme plz sir
ajay_bhargav
Thu Jul 24 2014, 01:06 AM
@R.ABHISHEK where? I dont see it. is it in forum?
Wed Jul 23 2014, 05:49 AM
R.ABHISHEK
sir,pls message on microcontroller 8051 assambly language new program
Wed Jul 23 2014, 05:47 AM
R.ABHISHEK
sir,pls message on 8051 microcontroller assambly language program new quastions
ajay_bhargav
Tue Jul 22 2014, 09:18 AM
@Pragya Android application is taken from google play. Only Author has its source with him. Application is only used in this project.
Tue Jul 22 2014, 04:58 AM
Pragya
plz send me 8051 code and android code for android based device controller via Bluetooth .Here in this project I am using Hc-06 Bluetooth module
Thu Jul 10 2014, 09:57 AM
Caleb
plz someone mail me the source code for that project
Thu Jul 10 2014, 09:57 AM
Caleb
http://www.8051projects.net/download-d188-control-your-pc-tv-remote.html

Downloads

Comments

NexusRevZ
Tue Jul 29 2014, 09:29 PM
kritz22
Mon Jul 28 2014, 10:33 AM
Abbasans786
Mon Jul 28 2014, 03:15 AM
Imran.pk
Fri Jul 25 2014, 07:50 PM
PavanKh
Fri Jul 25 2014, 12:56 AM
vinosentinal
Mon Jul 21 2014, 08:28 PM
niks_here
Sun Jul 20 2014, 05:38 PM
athiramsankar
Sun Jul 20 2014, 12:00 PM

Online

Guests: 36, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 01:37 AM

Members: 37484
Newest member: NexusRevZ