3

I have Arduino Uno and 0.96" I2C Oled 4 Pinned display. These are my Arduino codes:

#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE);    // VDD=5V SCL=A5 SDA=A4

int a = 10;

void setup(void) {
}

void loop(void) {

  u8g.setFont(u8g_font_gdr25r);
  u8g.drawStr(8, 30, "E");
  u8g.setFont(u8g_font_gdr25r);
  u8g.drawStr(30, 30,"l");
  delay(2000);  

  //  u8g.println(a);  //This code raw is not working
  //  delay(2000);
}

I am trying to indicate integer type variable is called "a" to the OLED screen, but u8glib library hasn't got

println( (int) a );

function to do this. I only see

u8g.drawStr();

function that this can't handle integer variables to the display. How can I do that?

5

The U8glib user reference page mentions a couple of ways to print the value of a number using ASCII characters.

Eg, following the idea at the second mention of sprintf at above link:

char buf[9];
sprintf (buf, "%d", a);
u8g.drawStr(33, 33, buf);

Edit: The above follows the example at the link, but I've struck it out because in general snprintf is safer than sprintf. See below.

enum {BufSize=9}; // If a is short use a smaller number, eg 5 or 6 
char buf[BufSize];
snprintf (buf, BufSize, "%d", a);
u8g.drawStr(33, 33, buf);

The other way is via print. (Search for U8GLIB::print in above link, and also see arduino.cc's Print docs).

Eg:

u8g.print(a);

To get a newline effect, you may need to have a variable keeping track of the current line number; add 1 to it to get next line's number, and use that as a position parameter in a drawStr call.

0

Ok, I have found the solution (Thank you @jwpat7) Here is my working code:

#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE);  // VDD=5V GND=GND SCL=A5 SDA=A4

int a = 0;

void setup() {      }

void loop() {

u8g.firstPage(); 
 do {
u8g.setFont(u8g_font_gdr25r);
//u8g.drawStr(8, 30, "Eeee");

char buf[9];
sprintf (buf, "%d", a);
u8g.drawStr(18, 3, buf);

  } while( u8g.nextPage() );
  delay(200); 
}

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.