Does anyone have lately tried this code? I can't get it working, nor the mem code nor the one on "gomiun" website. With this code, from the playground, I get only an infinite " ; ; " on my console...
Using pin 8 (reading the class)

@MikeT
You really should post your library for the BlazePro on the PlayGround!

Does the code for the GREEN matrix support up to 4 matrix?
Are there some library compatible with the green and the red matrix?
F

Good tip! I will try as soon as possible, thaks

I have this kit, but I never had the time to try it. I still have a question in mind.. it is possible in your opinion to create a "duplex" connection? Fede

I hope this can be useful. I have done a replica of this project:
http://dclausen.net/projects/ledcyl/
wich use the "TLC5940NT 16 channel PWM constant-current LED driver" . They can be linked together with serial interface.

This is my code, it's working but perhaps not perfect Keep in mind that is my code there is also the part of code that is needed by my rtc.

Code:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WProgram.h>
#include <DS1307.h>

int rtc[7];
byte data[56];
char orario[16]; //non cambiare 16 perchè per qualche motivo non va piu' niente dopo
char dataOdierna[16];
int anno;
int changeScreen = 0;
int k = 0;
int primaAccensione = 0;

#define expander 0x20  // Address with three address pins grounded (B0100000).
                     // Note that the R/W bit is not part of this address.
volatile byte count = 0;


uint8_t bell[8]  = {0x4,0xe,0xe,0xe,0x1f,0x0,0x4};
uint8_t note[8]  = {0x2,0x3,0x2,0xe,0x1e,0xc,0x0};
uint8_t clock[8] = {0x0,0xe,0x15,0x17,0x11,0xe,0x0};
uint8_t heart[8] = {0x0,0xa,0x1f,0x1f,0xe,0x4,0x0};
uint8_t duck[8]  = {0x0,0xc,0x1d,0xf,0xf,0x6,0x0};
uint8_t check[8] = {0x0,0x1,0x3,0x16,0x1c,0x8,0x0};
uint8_t cross[8] = {0x0,0x1b,0xe,0x4,0xe,0x1b,0x0};
uint8_t retarrow[8] = {      0x1,0x1,0x5,0x9,0x1f,0x8,0x4};
  
LiquidCrystal_I2C lcd(expander,8,2);  // set the LCD address to 0x20 for a 16 chars and 2 line display


void setup()
{
  Wire.begin();
  attachInterrupt(0, expanderInterrupt, CHANGE);
 
  Serial.begin(9600);
  lcd.init();        // initialize the lcd
  lcd.noBacklight(); // accende e spegne l'uscita sul pin 12.
                     // lcd.backlight();
                     // sink current +5V------+LED-------330Rresistor------P8574pin
  
  lcd.createChar(0, bell);
  lcd.createChar(1, note);
  lcd.createChar(2, clock);
  lcd.createChar(3, heart);
  lcd.createChar(4, duck);
  lcd.createChar(5, check);
  lcd.createChar(6, cross);
  lcd.createChar(7, retarrow);
  lcd.home();
  
  lcd.print(" System");
  lcd.setCursor(0, 1);
  lcd.print(" Ready.");
  delay(1000);
  for(int i=0; i<9; i++)  {
    lcd.scrollDisplayLeft();
    delay(100);
  }
  lcd.clear();
  lcd.home();
  
  //RTC SETUP
  /*RTC.stop();
  RTC.set(DS1307_SEC,1);
  RTC.set(DS1307_MIN,26);
  RTC.set(DS1307_HR,1);
  RTC.set(DS1307_DOW,4);
  RTC.set(DS1307_DATE,30);
  RTC.set(DS1307_MTH,10);
  RTC.set(DS1307_YR,9);
  RTC.start();*/
  
  for(int i=0; i<56; i++)  {
    RTC.set_sram_byte(65,i);
  }

}

void loop()
{
  RTC.get(rtc,true);

  /*for(int i=0; i<7; i++)
   {
   Serial.println(rtc[i]);
   Serial.print(" ");
   }
   Serial.println();*/

  //rtc[0] --> secondi
  //Tramite questo IF faccio lampeggiare il : per i secondi
  if (rtc[0]%2) {
    sprintf(orario,"%02d:%02d",rtc[2],rtc[1]); //%02d converte 9 in 09 e 32 in 32
  }
  else {
    sprintf(orario,"%02d %02d",rtc[2],rtc[1]);
  }
  Serial.println(orario);
  
  anno=rtc[6]-2000;
  sprintf(dataOdierna,"%02d/%02d/%02d",rtc[4],rtc[5],anno);
  
  
  if (changeScreen==0) {
    lcd.setCursor(1,0);
    lcd.print(orario);
    lcd.setCursor(7,0);
    lcd.print(2, BYTE);
    lcd.setCursor(0,1);
    lcd.print(dataOdierna);
  }
  else if (changeScreen==1) {
    lcd.setCursor(0,0);
    lcd.print(1, BYTE);
    lcd.setCursor(1,0);
    lcd.print("XX");
    lcd.setCursor(4,0);
    lcd.print(4, BYTE);
    lcd.setCursor(5,0);
    lcd.print("XX");
    lcd.setCursor(0,1);
    lcd.print("hcca XX");
  }
  
  if (count == 1) {
    //Serial.println(expanderRead(),BIN);
    count = 0;
    attachInterrupt(0, expanderInterrupt, LOW);
    
    k++;
    if (primaAccensione==0) {changeScreen=0; primaAccensione++;}
    else if (k==1) { changeScreen=!changeScreen; lcd.clear(); }
    else if (k>1) { k=0; }
    //Serial.println(k);
  }
    
}

// display all keycodes
void displayKeyCodes(void) {
  uint8_t i = 0;
  while (1) {
    lcd.clear();
    lcd.print("Codes 0x"); lcd.print(i, HEX);
    lcd.print("-0x"); lcd.print(i+8, HEX);
    lcd.setCursor(0, 1);
    for (int j=0; j<8; j++) {
      lcd.print(i+j, BYTE);
    }
    i+=8;  
    delay(4000);
  }
}

// Funzioni per interrupt da arduino
void expanderInterrupt() {    
  detachInterrupt(0);
  count = 1;
}

void expanderWrite(byte _data ) {
  Wire.beginTransmission(expander);
  Wire.send(_data);
  Wire.endTransmission();
}

byte expanderRead() {
  byte _data;
  Wire.requestFrom(expander, 1);
  if(Wire.available()) {
    _data = Wire.receive();
  }
  return _data;
}

Yei! I have double checked every connection again and I have ended up with a pair of codes in output what I press my button. I was able to idendify this to change the data on my lcd screen. I have still to semplify my code but more or less is working now. I will post it as soon as possible. The code of Yot was my key in this work, thanks again! Thanks to everyone

I am programming this system to sobstitute the lcd clock of my car, to have an enhanced clock and the possibility to switch visual to see the temperature of many electronics I have installed (via i2c) into.

I have correct the "==" typo, but my pullup resistor (10k) is from the +5v line to the INT on che PCF, I thought it was to set like this reading your post... I will change if connecting the pullup to the pin "2" on my arduino diecimila and test again tonight. I have changed the external interrupt from 5 to 0 if I can remeber exactly. I will check as soon as I came back home! Fede

Thank you for discussing about this topic, I am learning many things.
By the way, still I can't undestanding I am doing it right. Following the code of Yot, in my serial debug I have

Code:

11001001
11001001
11001001
11001001
11001001

no stop (well, I have some wire attached to the expander)
When I press the button for less than one sec i have

Code:

1001001
1001001
1001001
1001001
1001001
1001001

So I can see that something change, and when I release my button I have again, over and over the code inserted at the top (11001001).
Is this supposed to be correct? It will be a little tricky to hook...

Federico

With the help of your code as test I have read a bit of documentation from the arduino site and now I am doing some test.
If I understand it right when I press the button, connected to ground, I receve a different binary number, so I can hook this to actions. Am I right?

Still have to test it, but can you tell me if the pin used from the arduino to the external interrupt is still usable?

Federico

Hi Mario,
I have already planned not to use the backlight with your library because I will always need the backlight on. I could use the pin 12, but still I have to understand how. I am working on it...
Thanks, Fede

I will be absolutly fine with a normal digital button
I need this button to change the state of the visualization on the lcd, but looks like every example on the forum is about using the expander as output, and not as input (on a single pin)

Hi, I have a PCF8574p and I am using it with an lcd. This works fine.
The library that I use let a pin of the PCF, the 13, free.
I wish to use this pin of the port expander as an input pin, to read the pressure of a button, but I can't understand how, through the wire library (i think that i need this).
Is it possible to do this? Does anyone knows where I can look for understanding how to do this? Thanks, Fede

Thank you, I will try also a smaller cap, to see what happens!
Federico