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.

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Fri Feb 05 2016, 08:33 AM
SANJYOT JADHAV
sir did we have to use Gsm modem for testing the circuit on proteus
Tue Feb 02 2016, 11:17 AM
upendra kumar
i want information about 3-phase motor control using gsm technology
Sat Jan 16 2016, 05:33 PM
Kenneth Etuk
Hi everyone, I need help with a project involving MCU,rttc, and DC motor. I will pay for it. please reply to my mail [email protected] if you are interested. thanks
ExperimenterUK
Sat Jan 16 2016, 02:08 AM
@Kabona Log in and create a thread. Tell us what you want to do
Tue Jan 12 2016, 08:24 PM
Kabona
how can I make my pc be input and output device for the microcontroller
Sat Jan 09 2016, 07:04 AM
Ravz
Thank u..... one more doubt Will ultrasonic sensor HC-SR04 works with aurdino board in operating system linux
Tommy.Kofisterix
Fri Jan 08 2016, 08:50 PM
I know it detects also the mud on rear bumper, this means other obstacles will
Tommy.Kofisterix
Fri Jan 08 2016, 08:48 PM
Hey hi, hello
Tue Jan 05 2016, 03:03 PM
Ravz
Anybody here????
Tue Jan 05 2016, 02:52 PM
Ravz
Will ultrasonic sensors detect obstacles when cloth or any other objects covers the sensor????

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ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Feb 04 2016, 04:10 AM
Sir I didn't understand that. Could you explain ab...
sankalp_s Avatar
Posted By sankalp_s
Tue Feb 02 2016, 07:26 PM
but good use of sub routines will save a lot of ...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Feb 02 2016, 12:25 AM
after removing ALLON instruction it's working fine...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Feb 02 2016, 12:14 AM
Which micro controller are you using ?.Does it hav...
sankalp_s Avatar
Posted By sankalp_s
Sat Jan 30 2016, 07:40 PM
You need to explain exactly what you want the code...
ExperimenterUK Avatar
Posted By ExperimenterUK
Sat Jan 30 2016, 06:57 PM
>sir can you code this in any other method?You nee...
sankalp_s Avatar
Posted By sankalp_s
Sat Jan 30 2016, 06:47 PM
CALL ALLONCLR L1CLR L2CLR L3CLR L4CALL DELAY ;del...
designAAA Avatar
Posted By designAAA
Sat Jan 30 2016, 10:03 AM
I have used to timer 2 external pin for other purp...
designAAA Avatar
Posted By designAAA
Sat Jan 30 2016, 09:00 AM
Hello,I am building the dotmatrix display, where I...
ExperimenterUK Avatar
Posted By ExperimenterUK
Sat Jan 30 2016, 12:40 AM
ok sir but what is solution for it. will i have to...