PIC32MX: Parallel LCD - Revision history

NickMarchuk at 19:27, 11 January 2010

2010-01-11T19:27:45Z

← Older revision		Revision as of 14:27, 11 January 2010
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	</pre></code>		</pre></code>

	Write the contents of an ~~integer~~ using		Write the contents of a variable using
	<code><pre>		<code><pre>
			char buffer[5]; // this will store the string
	// write the value of int counter
			int n; // this is the number of characters in the string after it has been converted
	putsLCD("\fCounter = %f", counter); //currently not supported NDM 1/4/10
			short a = 10; // the number we will convert to a string
			n=sprintf(buffer, "%d", a); // make the string and see how many characters there are
			putsLCD("a = "); // write some text
			putsLCD(buffer); // write the contents of the variable
	</pre></code>		</pre></code>

NickMarchuk: /* Files and Example Code */

2010-01-11T19:24:20Z

Files and Example Code

Show changes

NickMarchuk: /* Files and Example Code */

2010-01-11T19:04:44Z

Files and Example Code

← Older revision		Revision as of 14:04, 11 January 2010
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	== Files and Example Code ==		== Files and Example Code ==

	Include the following h and c files to your project:		Include the following h and c files to your project: [[Media:LCD_NU32.zip\|h and c files]]

	'''LCD.h'''		'''LCD.h'''

NickMarchuk: /* Files and Example Code */

2010-01-11T19:03:34Z

Files and Example Code

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NickMarchuk at 19:00, 11 January 2010

2010-01-11T19:00:56Z

← Older revision		Revision as of 14:00, 11 January 2010
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⚫	The popular HD44780 (and compatible chipsets) can be interfaced to the NU32 PIC32 board using 6 pins for easy character output to an LCD. This can be highly useful in either debugging or generating a more complex user interface for a PIC (or other microcontroller)-based device.
			== Parallel LCD ==

		⚫	The popular HD44780 (and compatible chipsets) can be interfaced to the NU32 PIC32 board using 6 pins for easy character output to an LCD. This can be highly useful in either debugging or generating a more complex user interface for a PIC (or other microcontroller)-based device.

			This implementation of an HD44780 LCD uses only 6 I/O on the PIC, but is not optimized for speed. If you need more efficient output, more pins can be used for communication, and this code would need to be altered slightly, but for debugging purposes start with this implementation.

			== LCD Hookup ==

	First you will need to locate the appropriate datasheet for the actual LCD you are using. What you will want to look up in there is the arrangement of connectors on the top-left of the display, and their names so that you can appropriately match the right connectors with the correct pins on the microcontroller, and in turn with the correct software identifiers for those connections. An example of one such pin arrangement is below.		First you will need to locate the appropriate datasheet for the actual LCD you are using. What you will want to look up in there is the arrangement of connectors on the top-left of the display, and their names so that you can appropriately match the right connectors with the correct pins on the microcontroller, and in turn with the correct software identifiers for those connections. An example of one such pin arrangement is below.
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	The NU32 board is based on 3.3V logical outputs, which works fine for most LCDs.		The NU32 board is based on 3.3V logical outputs, which works fine for most LCDs.

			== LCD Commands ==

	In the main.c file, before the main while loop, you must initialize the LCD		In the main.c file, before the main while loop, you must initialize the LCD
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	putsLCD("\fCounter = %f", counter); //currently not supported NDM 1/4/10		putsLCD("\fCounter = %f", counter); //currently not supported NDM 1/4/10
	</pre></code>		</pre></code>

			== Files and Example Code ==

	Include the following h and c files to standardize the communication:		Include the following h and c files to standardize the communication:

NickMarchuk at 18:46, 11 January 2010

2010-01-11T18:46:16Z

← Older revision		Revision as of 13:46, 11 January 2010
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	~~Using~~ 7 ~~pins~~ on ~~the~~ ~~PIC32~~ it is ~~possible~~ to ~~interface~~ ~~with~~ ~~the~~ ~~popular~~ ~~HD44780~~ ~~(and~~ ~~compatible chipsets)~~ for easy character output to an LCD. This can be highly useful in either debugging or generating a more complex user interface for a PIC (or other microcontroller)-based device.		The popular HD44780 (and compatible chipsets) can be interfaced to the NU32 PIC32 board using 6 pins for easy character output to an LCD. This can be highly useful in either debugging or generating a more complex user interface for a PIC (or other microcontroller)-based device.

	First you will need to locate the appropriate datasheet for the actual LCD you are using. What you will want to look up in there is the arrangement of connectors on the top-left of the display, and their names so that you can appropriately match the right connectors with the correct pins on the microcontroller, and in turn with the correct software identifiers for those connections. An example of one such pin arrangement is below.		First you will need to locate the appropriate datasheet for the actual LCD you are using. What you will want to look up in there is the arrangement of connectors on the top-left of the display, and their names so that you can appropriately match the right connectors with the correct pins on the microcontroller, and in turn with the correct software identifiers for those connections. An example of one such pin arrangement is below.

	<table>		<table>
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	</table>		</table>

	Your controller may differ from this one. Occasionally even if you've got the right datasheet these pin numbers can be backwards. If it has a backlight, try powering that up first and ensure that works.		Your controller may differ from this one. Occasionally even if you've got the right datasheet these pin numbers can be backwards. If it has a backlight, try powering that up first and ensure that works.

	Next, you'll need to wire up the LCD for power, and the connections with the pic.		Next, you'll need to wire up the LCD for power, and the connections with the pic.
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	</table>		</table>

	The VEE pin on the LCD sets the contrast of the characters on the LCD. ~~Play~~ with a voltage around 1V to get a nice contrast, or hook it to GND through a 1.5kOhm resistor, which also seems to work well.		The VEE pin on the LCD sets the contrast of the characters on the LCD. Create with a voltage around 1V using a 10k pot to get a nice contrast, or hook it to GND through a 1.5kOhm resistor, which also seems to work well.

	If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to check that your LCD works.		If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to set your contrast and check that your LCD works.

	The NU32 board is based on 3.3V logical outputs, which works fine for most LCDs.		The NU32 board is based on 3.3V logical outputs, which works fine for most LCDs.

	In ~~your~~ main.c file, before ~~your~~ main while loop, you must initialize the LCD		In the main.c file, before the main while loop, you must initialize the LCD
	<code><pre>		<code><pre>
	lcd_init(); // Always call this first		lcd_init(); // Always call this first

NickMarchuk at 18:41, 11 January 2010

2010-01-11T18:41:14Z

← Older revision		Revision as of 13:41, 11 January 2010
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	<tr><td>1 - VSS</td><td>GND</td></tr>		<tr><td>1 - VSS</td><td>GND</td></tr>
	<tr><td>2 - VCC</td><td>+5V</td></tr>		<tr><td>2 - VCC</td><td>+5V</td></tr>
	<tr><td>3 - VEE</td><td>~~1.5kOhm to GND~~</td></tr>		<tr><td>3 - VEE</td><td>~1V</td></tr>
	<tr><td>4 - RS</td><td>D4</td></tr>		<tr><td>4 - RS</td><td>D4</td></tr>
	<tr><td>5 - R/W</td><td>D9</td></tr>		<tr><td>5 - R/W</td><td>GND</td></tr>
	<tr><td>6 - E</td><td>D10</td></tr>		<tr><td>6 - E</td><td>D10</td></tr>
	<tr><td>7 - DB0</td><td>NC</td></tr>		<tr><td>7 - DB0</td><td>NC</td></tr>
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	If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to check that your LCD works.		If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to check that your LCD works.

	The NU32 board is based on 3.3V logical outputs, ~~but~~ ~~some~~ ~~LCDs~~ ~~require~~ ~~5V,~~ ~~so put the PIC output pins in open drain mode and use pull up resistors to +5V to enable the PIC to output 5V~~.		The NU32 board is based on 3.3V logical outputs, which works fine for most LCDs.

	<code><pre>
	//Set D0-4,D9-10 as a digital output, open drain
	LATD \|= 0x061F; TRISD &= 0xF9E0;
	mPORTDOpenDrainOpen(BIT_0 \| BIT_1 \| BIT_2 \| BIT_3 \| BIT_4 \| BIT_9 \| BIT_10);
	</pre></code>

	In your main.c file, before your main while loop, you must initialize the LCD		In your main.c file, before your main while loop, you must initialize the LCD

NickMarchuk at 02:22, 5 January 2010

2010-01-05T02:22:38Z

← Older revision		Revision as of 21:22, 4 January 2010
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	If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to check that your LCD works.		If you power the LCD but do not send it any commands, the top row should fill with boxes. Use this to check that your LCD works.

	The NU32 board is based on 3.3V logical outputs, but some LCDs require 5V, so ~~we will~~ put the PIC output pins in open drain mode and use pull up resistors to +5V to enable the PIC to output 5V.		The NU32 board is based on 3.3V logical outputs, but some LCDs require 5V, so put the PIC output pins in open drain mode and use pull up resistors to +5V to enable the PIC to output 5V.

	<code><pre>		<code><pre>
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	LATD \|= 0x061F; TRISD &= 0xF9E0;		LATD \|= 0x061F; TRISD &= 0xF9E0;
	mPORTDOpenDrainOpen(BIT_0 \| BIT_1 \| BIT_2 \| BIT_3 \| BIT_4 \| BIT_9 \| BIT_10);		mPORTDOpenDrainOpen(BIT_0 \| BIT_1 \| BIT_2 \| BIT_3 \| BIT_4 \| BIT_9 \| BIT_10);
			</pre></code>

			In your main.c file, before your main while loop, you must initialize the LCD
			<code><pre>
			lcd_init(); // Always call this first
	</pre></code>		</pre></code>

NickMarchuk at 02:20, 5 January 2010

2010-01-05T02:20:28Z

Show changes

NickMarchuk at 02:54, 4 January 2010

2010-01-04T02:54:00Z

← Older revision		Revision as of 21:54, 3 January 2010
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	}		}
	#endif		#endif



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	</pre></code>		</pre></code>

			To test these commands, here is a basic main file that writes some text:
	main.c		main.c
	<code><pre>		<code><pre>
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	#include "HardwareProfile.h"		#include "HardwareProfile.h"
	#include <plib.h>		#include <plib.h>
	//#include "LCD.h"

	#define SYS_FREQ 80000000L		#define SYS_FREQ 80000000L