HD44780 - Revision history

Michaelb at 16:18, 21 January 2017

2017-01-21T16:18:40Z

Michaelb: /* I2C */

2016-12-09T23:53:48Z

‎I2C

Michaelb: /* I2C */

2016-12-09T23:51:15Z

‎I2C

Michaelb at 23:48, 9 December 2016

2016-12-09T23:48:22Z

Michaelb: /* Pinning */

2016-12-09T23:46:48Z

‎Pinning

Michaelb: /* See also */

2016-12-09T23:45:59Z

‎See also

Michaelb: /* See also */

2016-12-09T23:45:02Z

‎See also

Michaelb at 23:38, 9 December 2016

2016-12-09T23:38:11Z

Michaelb at 23:34, 9 December 2016

2016-12-09T23:34:40Z

Michaelb: /* Pinning */

2016-12-09T23:24:23Z

‎Pinning

@@ Line 12: / Line 12: @@
 |CODE=[https://github.com/ethersex/ethersex/tree/master/hardware/lcd https://github.com/ethersex/ethersex/tree/master/hardware/lcd]
 }}
 The '''HD44780 module''' provides support for common '''alphanumeric character LCDs''' using Hitachis HD44780 and compatible controllers.

@@ Line 196: / Line 196: @@
 The I2C connection type supports either the 8 Bit PCF8574x, as it is found on the Pollin AVR Net-IO Add-On board, or the 16 Bit MCP23017 I2C Port Expander.
-LCDs up to 80 characters and only one HD44780 controller may be connected to a PCF8574x including the backlight control pin. LCDs with more than 80 characters require a second enable pin. The address of the port expander and the pinning for the LCD has to be specified for your hardware using the macros shown below. The macro HD44780_PCF8574x_MAPPING defines the pinning for displays with only one enable signal and backlight control, the macro HD44780_PCF8574x_MULTI_MAPPING for displays with two enable signals. Note that backlight control is not supported when using the HD44780_PCF8574x_MULTI_MAPPING macro. The pinning shown in the examples below matches the pinning found on the Pollin AVR Net-IO Add-On board. Remember that you have to replace the inverting backlight control circuitry with a direct connection from the PCF8574x to the 16 pin header to connect displays with two enable signals to this board.
+LCDs up to 80 characters and only one HD44780 controller may be connected to a PCF8574x including the backlight control pin. LCDs with more than 80 characters require a second enable pin connected to the PCF8574x instead of the backlight control pin. The address of the port expander and the pinning for the LCD has to be specified for your hardware using the macros shown below. The macro HD44780_PCF8574x_MAPPING defines the pinning for displays with only one enable signal and backlight control, the macro HD44780_PCF8574x_MULTI_MAPPING for displays with two enable signals. Note that backlight control is not supported when using the HD44780_PCF8574x_MULTI_MAPPING macro. The pinning shown in the examples below matches the pinning found on the Pollin AVR Net-IO Add-On board. Remember that you have to replace the inverting backlight control circuitry with a direct connection from the PCF8574x to the 16 pin header to connect displays with two enable signals to this board.
 The macros HD44780_MCP23017_MAPPING and HD44780_MCP23017_MULTI_MAPPING are used to map the LCD pins to one port of the MCP23017. Note that you have to specify either port A or B as shown below, mapping using mixed pins of both ports is not supported by the driver. The additional macro HD44780_MCP23017_MULTI_MAPPING_BL may be used to specify a backlight control signal on another MCP23017 port when the first port is occupied by a display with two enable signals. The driver exclusively controls the BL pin specified, the other 7 port pins may be used for different purposes.

@@ Line 196: / Line 196: @@
 The I2C connection type supports either the 8 Bit PCF8574x, as it is found on the Pollin AVR Net-IO Add-On board, or the 16 Bit MCP23017 I2C Port Expander.
-LCDs up to 80 characters and only one HD44780 controller may be connected to a PCF8574x including the backlight control pin. LCDs with more than 80 characters require a second enable pin. The address of the port expander and the pinning for the LCD has to be specified for your hardware using the macros shown below. The macro HD44780_PCF8574x_MAPPING defines the pinning for displays with only one enable signal and backlight control, the macro HD44780_PCF8574x_MULTI_MAPPING for displays with two enable signals. Note that backlight control is not supported when using the HD44780_PCF8574x_MULTI_MAPPING macro. The pinning shown in the examples below matches the pinning found on the Pollin AVR Net-IO Add-On board. Remember that you have to replace the inverting backlight control circuitry with a direct connection to connect displays with two enable signals to this board.
+LCDs up to 80 characters and only one HD44780 controller may be connected to a PCF8574x including the backlight control pin. LCDs with more than 80 characters require a second enable pin. The address of the port expander and the pinning for the LCD has to be specified for your hardware using the macros shown below. The macro HD44780_PCF8574x_MAPPING defines the pinning for displays with only one enable signal and backlight control, the macro HD44780_PCF8574x_MULTI_MAPPING for displays with two enable signals. Note that backlight control is not supported when using the HD44780_PCF8574x_MULTI_MAPPING macro. The pinning shown in the examples below matches the pinning found on the Pollin AVR Net-IO Add-On board. Remember that you have to replace the inverting backlight control circuitry with a direct connection from the PCF8574x to the 16 pin header to connect displays with two enable signals to this board.
 The macros HD44780_MCP23017_MAPPING and HD44780_MCP23017_MULTI_MAPPING are used to map the LCD pins to one port of the MCP23017. Note that you have to specify either port A or B as shown below, mapping using mixed pins of both ports is not supported by the driver. The additional macro HD44780_MCP23017_MULTI_MAPPING_BL may be used to specify a backlight control signal on another MCP23017 port when the first port is occupied by a display with two enable signals. The driver exclusively controls the BL pin specified, the other 7 port pins may be used for different purposes.

@@ Line 15: / Line 15: @@
 ----
-'''''THIS WIKI PAGE IS CURRENTLY WORK IN PROGRESS'''''
+'''''THIS WIKI PAGE IS CURRENTLY WORK IN PROGRESS AND REFLECTS UPCOMING CHANGES'''''
 ----

@@ Line 165: / Line 165: @@
 Please refer to the datasheet of '''your''' display! Wrong connections may lead to a permanent damage.
-The HD44780 module supports four different types of connection for the LCD: Direct, I2C, Serial and 2-Wire.
+The HD44780 module supports four different types of connection for the LCD: '''Direct''', '''I2C''', '''Serial''' and '''2-Wire'''.
 === Direct ===

@@ Line 250: / Line 250: @@
 == See also ==
- * [https://www.sparkfun.com/datasheets/LCD/HD44780.pdf Original HD44780 Datasheet at sparkfun]
- * [https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller wikipedia:Hitachi_HD44780_LCD_controller]
+* [https://www.sparkfun.com/datasheets/LCD/HD44780.pdf Original HD44780 Datasheet at sparkfun]
- * [https://www.mikrocontroller.net/articles/HD44780 mikrocontroller.net:HD44780]
+* [https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller wikipedia:Hitachi_HD44780_LCD_controller]

← Older revision		Revision as of 23:38, 9 December 2016
Line 248:		Line 248:
	')		')
	</code>		</code>
		+
		+	== See also ==
		+	[https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller wikipedia:Hitachi_HD44780_LCD_controller]
		+	[https://www.mikrocontroller.net/articles/HD44780 mikrocontroller.net:HD44780]

@@ Line 21: / Line 21: @@
 The '''HD44780 module''' provides support for common '''alphanumeric character LCDs''' using Hitachis HD44780 and compatible controllers.
-= Supported LC-Displays =
+== Supported LC-Displays ==
 The vast majority of all alphanumeric LC-Displays use Hitachis [https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller HD44780]
@@ Line 75: / Line 75: @@
 '''Note:''' The HD44780 module drivers supports '''alphanumeric character LCDs''' only. Ethersex also has limited support for some graphical displays. Have a look at the LC-Display configuration.
-= Configuration =
+== Configuration ==
    ...
@@ Line 157: / Line 157: @@
 :  Invert backlight logic for low active backlight circuits e.g. found on Pollin AVR NET-IO Add-on.
-= Pinning =
+== Pinning ==
 HD44780-based alphanumeric LCDs are connected via 8 databus-lines (D0..D7) and 3 control-lines (RS, EN, R/W). Displays with more than 80 characters usually utilize a second controller and require two EN-signals EN1 and EN2. Another signal BL is needed if backlight control ist required. To save some i/o-pins the HD44780 controller also supports a 4 Bit mode, using only D4..D7. The HD44780 module supports this 4 Bit mode only. Note that in general the signals D0..D3 should not be left open, use a pull-down or tie them to ground.
@@ Line 167: / Line 167: @@
 The HD44780 module supports four different types of connection for the LCD: Direct, I2C, Serial and 2-Wire.
-== Direct ==
+=== Direct ===
 The LCD signals RS, RW, EN (resp. EN1 and EN2), D4..D7 and BL are directly connected to AVR port pins. The driver makes no assumptions about the pin mapping, arbitrary pins from different ports may be used to drive the LCD signals. This connection type is Readback-capable.
@@ Line 192: / Line 192: @@
 </code>
-== I2C ==
+=== I2C ===
 The I2C connection type supports either the 8 Bit PCF8574x, as it is found on the Pollin AVR Net-IO Add-On board, or the 16 Bit MCP23017 I2C Port Expander.
@@ Line 226: / Line 226: @@
 </code>
-== Serial (using 74HCT164) ==
+=== Serial (using 74HCT164) ===
 The LCD is connected using a 74HC(T)164 shift register. Refer to Ulrich Radig's [http://www.ulrichradig.de/home/index.php/software/avr-webserver-software avr-webserver] for an example of this connection type. The connection is uni-directional, so no Readback. Don't use if speed is important, especially not for larger displays.
@@ Line 237: / Line 237: @@
 </code>
-== 2-Wire (using 74HCT4094) ==
+=== 2-Wire (using 74HCT4094) ===
 The LCD is connected using a 74HC(T)4094 shift register. Refer to [http://www.cczwei.de/atm18_downloads/071148-D%20CC2-AVR-board-2.pdf this] paper for an explanation and example of this connection type. The connection is uni-directional, so no Readback. Don't use if speed is important, especially not for larger displays.