Adafruit: 8x8 Yellow LED Matrix Panel - Revision history

Yoder: /* Overview */

2012-10-17T20:18:01Z

‎Overview

Xinyu1991 at 03:22, 16 October 2012

2012-10-16T03:22:21Z

Xinyu1991 at 03:18, 16 October 2012

2012-10-16T03:18:23Z

Xinyu1991 at 03:16, 16 October 2012

2012-10-16T03:16:59Z

Xinyu1991 at 03:16, 16 October 2012

2012-10-16T03:16:29Z

Xinyu1991 at 03:05, 16 October 2012

2012-10-16T03:05:39Z

Xinyu1991 at 03:00, 16 October 2012

2012-10-16T03:00:35Z

Xinyu1991 at 02:58, 16 October 2012

2012-10-16T02:58:06Z

Xinyu1991 at 02:57, 16 October 2012

2012-10-16T02:57:09Z

Xinyu1991 at 02:55, 16 October 2012

2012-10-16T02:55:18Z

← Older revision		Revision as of 20:18, 17 October 2012
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	== Overview ==		== Overview ==
		+
		+	<pre style="color:red">
		+
		+	Overview: 2
		+	Wiring: 2, nice clear picture
		+	Code: 2, nice animation
		+	git/Compiles with make: 2 make works
		+	Demo: 2
		+	Total: 10
		+	Comments: Looks good. Maybe you could post a video to YouTube and put a link here.
		+	</pre>

	The adafriut 8*8 yellow Led matrix has been used in my mini project 2. I'm using it to display some simple pattern, Chinese characters and even some simple animation.		The adafriut 8*8 yellow Led matrix has been used in my mini project 2. I'm using it to display some simple pattern, Chinese characters and even some simple animation.

@@ Line 47: / Line 47: @@
 </pre>
-The codes for the whole project can be found in my github: [https://github.com/xinyu1991/Mini-Project-2 Codes for Mini Project].
+The codes for the whole project can be found in my github: [https://github.com/xinyu1991/Mini-Project-2 Codes for Mini Project 2].
 == Demo Pictures of Display ==

← Older revision		Revision as of 03:18, 16 October 2012
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	[[File:The Martix Display U.JPG]]		[[File:The Martix Display U.JPG]]
		+
		+	That's my introduce to the Led Matrix. Hope you can have an enjoy experience while using the device.

← Older revision		Revision as of 03:16, 16 October 2012
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	[[File:The Matrix Display Love.JPG]]		[[File:The Matrix Display Love.JPG]]

−	[[File:The ~~Matrix~~ Display U.JPG]]	+	[[File:The Martix Display U.JPG]]

@@ Line 49: / Line 49: @@
 The codes for the whole project can be found in my github: [https://github.com/xinyu1991/Mini-Project-2 Codes for Mini Project].
-== Demo Video ==
+== Demo Pictures of Display ==
-[[File:Matrix Display Demo Vedio.jpg]]

← Older revision		Revision as of 03:05, 16 October 2012
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	== Demo Video ==		== Demo Video ==
		+	[[File:Matrix Display Demo Vedio.jpg]]

← Older revision		Revision as of 02:58, 16 October 2012
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	Here is the codes in file:		Here is the codes in file:
		+
		+	<pre>
		+	#include <errno.h>#include <string.h>#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include "i2c-dev.h"#include "i2cbusses.h"#include "MatrixLed.h"int main(int argc, char argv[]){ int res, i2cbus, address, size, file; int value, daddress; char filename[20]; int force = 0, readback = 1; int len; i2cbus = lookup_i2c_bus("3"); printf("i2cbus = %d\n", i2cbus); if (i2cbus < 0) help(); address = parse_i2c_address("0x70"); printf("address = 0x%2x\n", address); if (address < 0) help(); size = I2C_SMBUS_BYTE; daddress = 0x21; if (daddress < 0 \|\| daddress > 0xff) { fprintf(stderr, "Error: Data address invalid!\n"); help(); } file = open_i2c_dev(i2cbus, filename, sizeof(filename), 0); printf("file = %d\n", file); if (file < 0 \|\| check_funcs(file, size) \|\| set_slave_addr(file, address, force)) exit(1); switch (size) { case I2C_SMBUS_BYTE: daddress = 0x21; // Start oscillator (page 10) printf("writing: 0x%02x\n", daddress); res = i2c_smbus_write_byte(file, daddress); daddress = 0x81; // Display on, blinking off (page 11) printf("writing: 0x%02x\n", daddress); res = i2c_smbus_write_byte(file, daddress); daddress = 0xe7; // Full brightness (page 15) printf("writing: 0x%02x\n", daddress); res = i2c_smbus_write_byte(file, daddress); daddress = 0x00; // Start writing to address 0 (page 13) printf("writing: 0x%02x\n", daddress); res = i2c_smbus_write_byte(file, daddress); int i; while(1) { //Display the Square. display(Square1_bmp,res,daddress,file); display(Square2_bmp,res,daddress,file); display(Square3_bmp,res,daddress,file); display(Square4_bmp,res,daddress,file); display(Square5_bmp,res,daddress,file); display(Square6_bmp,res,daddress,file); display(Square7_bmp,res,daddress,file); //Display Love Heart. display(Love1_bmp,res,daddress,file); display(Love2_bmp,res,daddress,file); display(Love1_bmp,res,daddress,file); //Display I love U. display(I_bmp,res,daddress,file); display(Love1_bmp,res,daddress,file); display(U_bmp,res,daddress,file); //Display the Square. display(Square7_bmp,res,daddress,file); display(Square6_bmp,res,daddress,file); display(Square5_bmp,res,daddress,file); display(Square4_bmp,res,daddress,file); display(Square3_bmp,res,daddress,file); display(Square2_bmp,res,daddress,file); display(Square1_bmp,res,daddress,file); //Display Love Heart. display(Love1_bmp,res,daddress,file); display(Love2_bmp,res,daddress,file); display(Love1_bmp,res,daddress,file); } break; case I2C_SMBUS_WORD_DATA: res = i2c_smbus_write_word_data(file, daddress, value); break; case I2C_SMBUS_BLOCK_DATA: res = i2c_smbus_write_block_data(file, daddress, len, (const __u8 )block); break; case I2C_SMBUS_I2C_BLOCK_DATA: res = i2c_smbus_write_i2c_block_data(file, daddress, len, (const __u8 )block); break; default: / I2C_SMBUS_BYTE_DATA / res = i2c_smbus_write_byte_data(file, daddress, value); break; } if (res < 0) { fprintf(stderr, "Error: Write failed\n"); close(file); exit(1); } if (!readback) { / We're done / close(file); exit(0); } switch (size) { case I2C_SMBUS_BYTE: res = i2c_smbus_read_byte(file); value = daddress; break; case I2C_SMBUS_WORD_DATA: res = i2c_smbus_read_word_data(file, daddress); break; default: / I2C_SMBUS_BYTE_DATA / res = i2c_smbus_read_byte_data(file, daddress); } close(file); if (res < 0) { printf("Warning - readback failed\n"); } else if (res != value) { printf("Warning - data mismatch - wrote " "0x%0x, read back 0x%0x\n", size == I2C_SMBUS_WORD_DATA ? 4 : 2, value, size == I2C_SMBUS_WORD_DATA ? 4 : 2, res); } else { printf("Value 0x%0x written, readback matched\n", size == I2C_SMBUS_WORD_DATA ? 4 : 2, value); } exit(0);}
		+	</pre>

← Older revision		Revision as of 02:57, 16 October 2012
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	}		}
	</pre>		</pre>
		+
		+	Here is the codes in file:

← Older revision		Revision as of 02:55, 16 October 2012
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	[[File:Hardware Connection.jpg\|500px]]		[[File:Hardware Connection.jpg\|500px]]

−	As we can see in the picture, the VCC and GND are connected to the VCC and GND in the Bone. And the data pin is connected Pin D18, which is I2C2_SDA. Connect the clock pin to Pin D17, which is I2C2_SCL.	+	As we can see in the picture, the VCC and GND are connected to the VCC and GND in the Bone. And the data pin is connected Pin D18, which is I2C2_SDA. Connect the clock pin to Pin D17, which is I2C2_SCL. After the above connection, the hardware part is done.
		+
		+	== Software Design ==
		+
		+	The mainly work of the software here is to display the correct pattern. And the pattern can be depicted through write a correct value (1 or 0) to each LED in the matrix. 1 means the LED is on and 0 means the LED is off.
		+
		+	For example, the pattern of ❤ can be displayed through the array:
		+
		+	Heart_bmp[]={0x0C, 0x1E, 0x3E, 0x7C, 0x3E, 0x1E, 0x0C, 0x00};
		+
		+	I have write a function to implement the display:
		+
		+	<pre>
		+	//The Function to Display a BMP.
		+	int display(__u16 bmp[], int res, int daddress, int file)
		+	{
		+	int i;
		+	for(i=0; i<8; i++)
		+	{ block[i] = (bmp[i]&0xfe) >>1 \|
		+	(bmp[i]&0x01) << 7;
		+	}
		+
		+	res = i2c_smbus_write_i2c_block_data(file, daddress, 16,
		+	(__u8 *)block);
		+
		+	usleep(400000);
		+	}
		+	</pre>