{"id":184,"date":"2020-01-11T18:17:11","date_gmt":"2020-01-12T01:17:11","guid":{"rendered":"http:\/\/www.wolfpack.xyz\/blog\/?p=184"},"modified":"2020-04-04T03:42:04","modified_gmt":"2020-04-04T09:42:04","slug":"how-i-learned-to-stop-worrying-and-love-i2c","status":"publish","type":"post","link":"http:\/\/www.wolfpack.xyz\/blog\/?p=184","title":{"rendered":"…how I Learned to Stop Worrying and Love I2C"},"content":{"rendered":"\n

Some form of display is often vital on your arduino projects.Let me introduce you to the HD44780 character LCD. <\/p>\n\n\n\n

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It’s quite a common and cheap display solution that is relatively<\/em> easy to use. It often finds its way into many arduino starter kits for these reasons. Ive used it a few times in my projects but have always been annoyed by one aspect…. the high amount of pins and the requirement of a resistor for the backlight and a potentiometer for the contrast.<\/p>\n\n\n\n

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The typical wiring setup for the display<\/figcaption><\/figure>\n\n\n\n

As you can see the board uses up 6 data pins on your board which can be a pain on the smaller boards I’ve been using lately. Then I discovered I2C (I squared C).<\/p>\n\n\n\n

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I2C is a method of using addresses to run many devices on only 2 data lines.<\/figcaption><\/figure>\n\n\n\n

With this we can run these LCD displays with a total of 4 wires. This is handy on boards like the ESP8266 or ESP32 with few pins. I plan on using a I2C compatible display on a project in the near future. I ordered the larger 4 line version<\/a> in fact. <\/p>\n\n\n\n

The code for the I2C display is quite similar to the regular versions.<\/p>\n\n\n

\n#include <Wire.h> \n#include <LiquidCrystal_I2C.h>\n\nLiquidCrystal_I2C lcd(0x27,16,2);  \/\/ set the LCD address to 0x27 for a 16 columns and 2 row display\n\nvoid setup() {\n  lcd.init();       \/\/initialize lcd screen\n  lcd.backlight();  \/\/ turn on the backlight\n}\n\nvoid loop() {\n  delay(1000);                   \/\/wait for a second\n  lcd.setCursor(0,0);            \/\/ tell the screen to write on the top row\n  lcd.print("LCD TEST");         \/\/ tell the screen to write \u201chello, from\u201d on the top row\n  lcd.setCursor(0,1);            \/\/ tell the screen to write on the bottom row\n  lcd.print("Hello World!");     \/\/ tell the screen to write "Hello World!" on the bottom row\n}\n\n<\/pre><\/div>\n\n\n
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