Hi, i am doing a clock project with two adafruit 8x8 bicolor matrix and a RTC.
i am not really into strings, and when i try to put "now.hour();" in a temporary string it gives me an error (invalid conversion from 'unit8_t' to 'const char*')
basically what i want to do is take the actual time and put it into a string that i can print on the matrix
this is the code, can someone help?
Thank you
Fabrizio
#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
#include "RTClib.h"
Adafruit_BicolorMatrix matrixa = Adafruit_BicolorMatrix();
Adafruit_BicolorMatrix matrixb = Adafruit_BicolorMatrix();
String stringclock,stringtemp;
RTC_DS1307 RTC;
const int DS1307 = 0x68;
void setup() {
Serial.begin(9600);
Serial.println("8x8 LED Matrix Test");
DateTime now = RTC.now();
//this gives me the error
stringtemp=now.hour();
//adding the hour to the string
stringclock= stringclock+stringtemp;
//i know that i have to add puntuation and leading zeroes... i'll do it later when this is fixed
stringtemp=now.minute();
stringclock= stringclock+stringtemp;
//
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
delay(3000);
matrixa.begin(0x76); // pass in the address
matrixb.begin(0x77); // pass in the address
matrixa.setRotation(1);
matrixb.setRotation(1);
matrixa.clear();
matrixb.clear();
matrixa.writeDisplay();
matrixb.writeDisplay();
}
void loop() {
matrixa.setRotation(1);
matrixa.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrixa.setTextSize(1);
matrixa.setTextColor(LED_RED);
matrixb.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrixb.setTextSize(1);
matrixb.setTextColor(LED_RED);
for (int x=7; x>=-80; x--) {
matrixa.clear();
matrixa.setCursor(x,0);
matrixa.print(stringclock);
matrixa.writeDisplay();
matrixb.clear();
matrixb.setCursor(x+8,0);
matrixb.print(stringclock);
matrixb.writeDisplay();
delay(75);
}
}
I suggest that you don't use the String class. now.hour() will most likely return a byte, and you can store it in a char array by using a function such as itoa, or sprintf. The latter is much more powerful, but also requires much more memory.
I think i have some problem with the library, i have tried to incorporate another project with the etc and i can't make it to work in this project, it must be a some simple mistake i must find...
I see you're using the DS1307. Keep in mind how the Time Keeper Register works. Each value is a BCD number, so if you try to display the 8 bits as a single byte, it probably won't make much sense. So if you need seconds, you read register 0 and look at the low nibble. You can find BCD routines on this Forum.
#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
#include "RTClib.h"
// create three instances of the matrix
Adafruit_BicolorMatrix matrixa = Adafruit_BicolorMatrix();
Adafruit_BicolorMatrix matrixb = Adafruit_BicolorMatrix();
Adafruit_BicolorMatrix matrixc = Adafruit_BicolorMatrix();
RTC_DS1307 rtc;
const int DS1307 = 0x68; //address of the RTC
char time[30]; //
void setup() {
Serial.begin(9600);
Serial.println("8x8 LED Matrix Test");
matrixa.begin(0x76); // address of the first matrix (first installed from the left)
matrixb.begin(0x77); // address of the second
matrixc.begin(0x75); // address of the third
matrixa.setRotation(1);
matrixb.setRotation(1);
matrixc.setRotation(1);
matrixa.clear();
matrixb.clear();
matrixc.clear();
matrixa.writeDisplay();
matrixb.writeDisplay();
matrixc.writeDisplay();
matrixa.setBrightness(1);
matrixb.setBrightness(1);
matrixc.setBrightness(1);
matrixa.setTextWrap(false);
matrixb.setTextWrap(false);
matrixc.setTextWrap(false);
matrixa.setTextSize(1);
matrixb.setTextSize(1);
matrixc.setTextSize(1);
matrixa.setTextColor(LED_RED);
matrixb.setTextColor(LED_RED);
matrixc.setTextColor(LED_RED);
}
void loop() {
getTime();
// we start the loop at 7 so the text is out of the first matrix, and we stop when we have scrolled to -80 pixels
//this now has to be adjusted manually based on the number of chars to be displayed
for (int x=7; x>=-80; x--) {
matrixa.clear();
matrixa.setCursor(x,0);
matrixa.print(time);
matrixa.writeDisplay();
matrixb.clear();
matrixb.setCursor(x+8,0); //offset 8 pixels for the second matrix
matrixb.print(time);
matrixb.writeDisplay();
matrixc.clear();
matrixc.setCursor(x+16,0); //offset 16 pixels for the second matrix
matrixc.print(time);
matrixc.writeDisplay();
delay(70); //speed of the rolling text
}
}
void getTime(void)
{
//get the time and put it into "time" chars
DateTime now = rtc.now();
sprintf( time, "%02hhu:%02hhu:%02hhu", now.hour(), now.minute(), now.second() );
Serial.print(now.day(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.year(), DEC);
Serial.print(' ');
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
delay(1000);
}
