Spi lcd 1.2 protocol - Revision history

Cartridge1987 at 14:23, 30 November 2015

2015-11-30T14:23:23Z

Rew: /* set cursor position */

2012-02-14T10:21:11Z

set cursor position

Rew at 10:20, 14 February 2012

2012-02-14T10:20:50Z

Rew: Created page with 'To display a string on the LCD, just send over SPI the same bytes you would send to LCD, prefixed with the address of the LCD (the default address is 0x82). Bytes above 0xf0 ar…'

2012-02-14T09:43:22Z

Created page with 'To display a string on the LCD, just send over SPI the same bytes you would send to LCD, prefixed with the address of the LCD (the default address is 0x82). Bytes above 0xf0 ar…'

New page

To display a string on the LCD, just send over SPI the same bytes you would send to LCD, prefixed with the address of the LCD (the default address is 0x82).

Bytes above 0xf0 are "special".

0xf0 <xy> is set cursor. the <xy> byte is 3 bit line number and 5 bit position number. This addressing allows up to 8 lines of 32 characters.

0xf1 is clear LCD.

0xf2 <addr> is "set address". If you want to change the address the module reacts to. The address is stored in eeprom, and will remain this way after a powercycle.

0xf3 <contrast> is "set contrast". This will set the contrast to the value you specify. 0x40 is the default that works fine for the LCDs that we have.

0xf4 <backlight> is the "set backlight intensity" command. This will set the backlight intensity to the value specified.

0xf5 <byte> will send the byte as a command to the HD44780. You need this for example to use the user-defined characters.

0xff <byte> will send the byte to the LCD without special character processing. This allows you to send codes 0xf0 through 0xff to the LCD if required.

Other bytes are reserved and are currently implemented as a no-op.

@@ Line 18: / Line 18: @@
 Other bytes are reserved and are currently implemented as a no-op.
-= examples =
+= Examples =
-== read identification ==
+== Read identification ==
 read the identification string of the board. ('spi_lcd 1.3').
@@ Line 59: / Line 59: @@
 |}
-== set cursor position ==
+== Set cursor position ==
 move to line 1, character 5:
 {| border=1

@@ Line 66: / Line 66: @@
 | 0x82 || xx || select destination with address 0x82 for WRITE
 |-
-| 0xf1 || xx || port 0x11 = set cursor position.
+| 0xf0 || xx || port 0x11 = set cursor position.
 |-
 | 0x25 || xx  || 0x25 = 001 00101 = line 1 position 5.

@@ Line 18: / Line 18: @@
 Other bytes are reserved and are currently implemented as a no-op.
+= examples =
+== read identification ==
+read the identification string of the board. ('spi_lcd 1.3').
+{| border=1
+! data sent !! data recieved || explanation
+|-
+| 0x83 || xx || select destination with address 0x82 for READ.
+|-
+| 0x01 || xx || identify
+|-
+| xx || 0x73  || 's'
+|-
+| xx || 0x70  || 'p'
+|-
+| xx || 0x69  || 'i'
+|-
+| xx || ... || etc.
+|}
+== Send text to display ==
+Display the string "Hello World!" (only the first 5 bytes of the string shown).
+{| border=1
+! data sent !! data recieved || explanation
+|-
+| 0x82 || xx || select destination with address 0x82 for WRITE
+|-
+| 0x48 || xx  || 'H'
+|-
+| 0x65 || xx  || 'e'
+|-
+| 0x6c || xx  || 'l'
+|-
+| 0x6c || xx  || 'l'
+|-
+| 0x6f || xx  || 'o'
+|-
+| xx || ... || etc.
+|}
+== set cursor position ==
+move to line 1, character 5:
+{| border=1
+! data sent !! data recieved || explanation
+|-
+| 0x82 || xx || select destination with address 0x82 for WRITE
+|-
+| 0xf1 || xx || port 0x11 = set cursor position.
+|-
+| 0x25 || xx  || 0x25 = 001 00101 = line 1 position 5.
+|}