Font precedes symbols with A ^ - Solved

Projects Programming
1

I am trying to incorporate a degree symbol into my sketch/oled display, and i did, but it is always preceded by a capital A wearing a hat.

no doubt i am not introducing a glyph properly, but i can't seem to figure out how to do it.

i can find only 1 constructor for ssd1306 128x64 I2C arduino

any suggestions ?

#include <Arduino.h>
#include <U8g2lib.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

/*
  U8glib Example Overview:
    Frame Buffer Examples: clearBuffer/sendBuffer. Fast, but may not work with all Arduino boards because of RAM consumption
    Page Buffer Examples: firstPage/nextPage. Less RAM usage, should work with all Arduino boards.
    U8x8 Text Only Example: No RAM usage, direct communication with display controller. No graphics, 8x8 Text only.
    
*/

// Please UNCOMMENT one of the contructor lines below
// U8g2 Contructor List (Frame Buffer)
// The complete list is available here: https://github.com/olikraus/u8g2/wiki/u8g2setupcpp
// Please update the pin numbers according to your setup. Use U8X8_PIN_NONE if the reset pin is not connected
//U8G2_SSD1306_128X64_NONAME_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 12, /* dc=*/ 4, /* reset=*/ 6); // Arduboy (Production, Kickstarter Edition)
//U8G2_SSD1306_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_3W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* reset=*/ 8);
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // All Boards without Reset of the Display
//U8G2_SSD1306_128X64_NONAME_F_6800 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8);
//U8G2_SSD1306_128X64_NONAME_F_8080 u8g2(U8G2_R0, 13, 11, 2, 3, 4, 5, 6, A4, /*enable=*/ 7, /*cs=*/ 10, /*dc=*/ 9, /*reset=*/ 8);
//U8G2_SSD1306_128X64_VCOMH0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // same as the NONAME variant, but maximizes setContrast() range
//U8G2_SH1106_128X64_NONAME_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8);
//U8G2_SH1106_128X64_VCOMH0_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // same as the NONAME variant, but maximizes setContrast() range
//U8G2_SSD1306_128X32_UNIVISION_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ 21, /* data=*/ 20, /* reset=*/ U8X8_PIN_NONE);   // Adafruit Feather M0 Basic Proto + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);   // Adafruit Feather ESP8266/32u4 Boards + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);  // Adafruit ESP8266/32u4/ARM Boards + FeatherWing OLED
//U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ SCL, /* data=*/ SDA);   // pin remapping with ESP8266 HW I2C
//U8G2_SSD1306_64X48_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // EastRising 0.66" OLED breakout board, Uno: A4=SDA, A5=SCL, 5V powered
//U8G2_SSD1322_NHD_256X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Enable U8G2_16BIT in u8g2.h
//U8G2_SSD1322_NHD_256X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); // Enable U8G2_16BIT in u8g2.h
//U8G2_SSD1325_NHD_128X64_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 13, /* data=*/ 11, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
//U8G2_SSD1325_NHD_128X64_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=*/ 10, /* dc=*/ 9, /* reset=*/ 8); 
_PIN_NONE); // Seeedstudio Grove OLED 96x96
//U8G2_

// End of constructor list


void setup(void) {
  u8g2.begin();
}

void loop(void) {
  u8g2.clearBuffer(); // clear the internal memory
  u8g2.setFont(u8g2_font_ncenB14_tf); // choose a suitable font
  u8g2.drawStr(0,20,"Hello °"); // write something to the internal memory
  u8g2.sendBuffer(); // transfer internal memory to the display
  delay(1000);  
}
2

drawStr() takes a const char * so you can not have any chars > 128. You need to use the drawGlyth() function which can take a 16 bit value for what you want to draw.

3

can you tell me what that 16 bit value is. i don't have the hang of deciphering hex from a position in a table.

this is what my code is, and it produced nothing.

void loop(void) {
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB14_tf);	// choose a suitable font
  u8g2.drawStr(0,20,"Hello ");	// write something to the internal memory
  u8g2.drawGlyph(10,40,"°");
  u8g2.sendBuffer();					// transfer internal memory to the display
  delay(1000);  
}
4

the other thing is, as i read glyphs, they go into a particular location which i specify. but that is not what i am after. i want to reference table item 176 ° and have it inserted just like any other character.

i already fadged in using a small circle and moving it to a particular location, but that only works if no other text changes.

i don't get how a character can be shown in the table, and yet it can't be accessed.

5

Use u8g2.drawUTF8() instead of u8g2.drawStr().

6

it does draw the ° now, but it seems to still require an exact position. which is no good.

i was hoping that i could display text etc., like i can in adafruit GFX, where i can say

display.print("k"); display.print("l"); display("m"); and it will print out klm.
but it seems with u8g2 i have to give everything to be displayed and exact screen position. it won't naturally follow the previous element.

am i right about that ? i hope not.

7

After much floundering around, I found a solution (at least for what I wanted).

For my OLED, I found a font that includes the ° symbol (look at 176 in font tables that end with TF).
Include enableUTF8Print(); This solved the problem of having to specify screen position for the symbol.
As for 'first page' and 'next page', I don't know what that means, but it works and so I use it.

#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <U8g2lib.h>

int x=40;

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); //OLED constructor
  
void setup() {
  u8g2.begin();
  u8g2.enableUTF8Print();    // enable UTF8 support for the Arduino print() function
}                            

void loop() {
  
 // u8g2.setFont(u8g2_font_helvB24_tf);
  u8g2.setFont(u8g2_font_logisoso58_tf); 
  u8g2.setFontDirection(0);
  u8g2.firstPage();
  do {
    u8g2.setCursor(0, 65);
    u8g2.print(x);
    u8g2.print("°C");     // windows keyboard type alt+0176 to get ° symbol
  } while ( u8g2.nextPage() );
  delay(1000);
}