Hi,
I am hoping that one of your very intelligent people can help me. I am attempting to make a simple LED matrix of 8 x 8 using a Max 7221 chip and a PCB that has been made for the purpose. I am following instructions but the matrix is simply doing nothing. This is a picture of the board with the components on:
http://www.flickr.com/photos/105962916@N05/10371735036/
and here is the board with the LED and other wires attached:
http://www.flickr.com/photos/105962916@N05/10372213463/
I am using this code:
//We always have to include the library
#include "LedControl.h"
/*
Now we need a LedControl to work with.
***** These pin numbers will probably not work with your hardware *****
pin 12 is connected to the DataIn
pin 11 is connected to the CLK
pin 10 is connected to LOAD
We have only a single MAX72XX.
*/
LedControl lc=LedControl(12,11,10,1);
/* we always wait a bit between updates of the display */
unsigned long delaytime=100;
void setup() {
/*
The MAX72XX is in power-saving mode on startup,
we have to do a wakeup call
*/
lc.shutdown(0,false);
/* Set the brightness to a medium values */
lc.setIntensity(0,8);
/* and clear the display */
lc.clearDisplay(0);
}
/*
This method will display the characters for the
word "Arduino" one after the other on the matrix.
(you need at least 5x7 leds to see the whole chars)
*/
void writeArduinoOnMatrix() {
/* here is the data for the characters */
byte a[5]={B01111110,B10001000,B10001000,B10001000,B01111110};
byte r[5]={B00111110,B00010000,B00100000,B00100000,B00010000};
byte d[5]={B00011100,B00100010,B00100010,B00010010,B11111110};
byte u[5]={B00111100,B00000010,B00000010,B00000100,B00111110};
byte i[5]={B00000000,B00100010,B10111110,B00000010,B00000000};
byte n[5]={B00111110,B00010000,B00100000,B00100000,B00011110};
byte o[5]={B00011100,B00100010,B00100010,B00100010,B00011100};
/* now display them one by one with a small delay */
lc.setRow(0,0,a[0]);
lc.setRow(0,1,a[1]);
lc.setRow(0,2,a[2]);
lc.setRow(0,3,a[3]);
lc.setRow(0,4,a[4]);
delay(delaytime);
lc.setRow(0,0,r[0]);
lc.setRow(0,1,r[1]);
lc.setRow(0,2,r[2]);
lc.setRow(0,3,r[3]);
lc.setRow(0,4,r[4]);
delay(delaytime);
lc.setRow(0,0,d[0]);
lc.setRow(0,1,d[1]);
lc.setRow(0,2,d[2]);
lc.setRow(0,3,d[3]);
lc.setRow(0,4,d[4]);
delay(delaytime);
lc.setRow(0,0,u[0]);
lc.setRow(0,1,u[1]);
lc.setRow(0,2,u[2]);
lc.setRow(0,3,u[3]);
lc.setRow(0,4,u[4]);
delay(delaytime);
lc.setRow(0,0,i[0]);
lc.setRow(0,1,i[1]);
lc.setRow(0,2,i[2]);
lc.setRow(0,3,i[3]);
lc.setRow(0,4,i[4]);
delay(delaytime);
lc.setRow(0,0,n[0]);
lc.setRow(0,1,n[1]);
lc.setRow(0,2,n[2]);
lc.setRow(0,3,n[3]);
lc.setRow(0,4,n[4]);
delay(delaytime);
lc.setRow(0,0,o[0]);
lc.setRow(0,1,o[1]);
lc.setRow(0,2,o[2]);
lc.setRow(0,3,o[3]);
lc.setRow(0,4,o[4]);
delay(delaytime);
lc.setRow(0,0,0);
lc.setRow(0,1,0);
lc.setRow(0,2,0);
lc.setRow(0,3,0);
lc.setRow(0,4,0);
delay(delaytime);
}
/*
This function lights up a some Leds in a row.
The pattern will be repeated on every row.
The pattern will blink along with the row-number.
row number 4 (index==3) will blink 4 times etc.
*/
void rows() {
for(int row=0;row<8;row++) {
delay(delaytime);
lc.setRow(0,row,B10100000);
delay(delaytime);
lc.setRow(0,row,(byte)0);
for(int i=0;i<row;i++) {
delay(delaytime);
lc.setRow(0,row,B10100000);
delay(delaytime);
lc.setRow(0,row,(byte)0);
}
}
}
/*
This function lights up a some Leds in a column.
The pattern will be repeated on every column.
The pattern will blink along with the column-number.
column number 4 (index==3) will blink 4 times etc.
*/
void columns() {
for(int col=0;col<8;col++) {
delay(delaytime);
lc.setColumn(0,col,B10100000);
delay(delaytime);
lc.setColumn(0,col,(byte)0);
for(int i=0;i<col;i++) {
delay(delaytime);
lc.setColumn(0,col,B10100000);
delay(delaytime);
lc.setColumn(0,col,(byte)0);
}
}
}
/*
This function will light up every Led on the matrix.
The led will blink along with the row-number.
row number 4 (index==3) will blink 4 times etc.
*/
void single() {
for(int row=0;row<8;row++) {
for(int col=0;col<8;col++) {
delay(delaytime);
lc.setLed(0,row,col,true);
delay(delaytime);
for(int i=0;i<col;i++) {
lc.setLed(0,row,col,false);
delay(delaytime);
lc.setLed(0,row,col,true);
delay(delaytime);
}
}
}
}
void loop() {
writeArduinoOnMatrix();
rows();
columns();
single();
}
which is some simple demo code supplied with the LED library. I have made sure to the best of my knowledge that I have connected the correct pin sequence here:
http://www.flickr.com/photos/105962916@N05/10371719304/
I have connected power through a 5v voltage regulator. I have used a multimeter to check the 5v is getting to the board and the chip which it is. I have used the multimeter on the LED strips and appear to be getting around 1v per strip.
The sequence I have used to get the code to the board is as follows:
Open Arduino 1.0.5 on my Mac with the LED library included and paste in the code
Connect the Arduino PIN outs to the PCB
Plug the Arduino into my Mac via USB
Supply power to my PCB
Click 'upload' on the Arduino software on my Mac
It reports data upload complete and the Uno flashes for a minute and then has the constant amber light
Then......nothing. I get no response from the matrix. I have clicked the reset button, again the Arduino flashes but no response from the matrix.
Am I doing something wrong? If not, could somebody advice me of the fault finding process from here.
Thank you for reading my massive post lol.