I2C Display Error

hello ,

i want to make this project but it does not work, when i upload the file is says “error: ‘POSITIVE’ was not declared in this scope” and it shows some characters and it flickers.

i tried this topic : https://forum.arduino.cc/index.php?topic=214356.0 but it didnt help me
i tried multiple lib. : https://bitbucket.org/fmalpartida/new-liquidcrystal/downloads/?tab=downloads
but, nothing …

what is the apropiate library for my code ?

// Set the pins on the I2C chip used for LCD connections:
// addr, en,rw,rs,d4,d5,d6,d7,bl,blpol

LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

lcd.begin(20,4); // initialize the lcd for 16 chars 2 lines, turn on backlight

Load the HD44780 library in the IDE itself, and study the examples provided including how to call that library.

Read the instructions for posting to understand how to post questions.

For an I2C LCD display to work, the I2C address and the I2C backpack to LCD pin mapping must be correct. If the library default settings for either or both are not correct the LCD will not work. You can try to figure out the right pin mapping and use an I2C scanner to find the address, but if you install and use the hd44780 library that is done automatically by the library.

Install the hd44780 library. The hd44780 library is the best available for I2C LCDs. The library is available in the Library Manager. Go to Library Manager (in the IDE, Sketch, Include Libraries, Manage Libraries) and in the Topics dropdown choose Display and in the Filter your search box enter hd44780. Select and install the hd44780 library by Bill Perry.

The class that you want to use is the hd44780_I2Cexp class. There are examples to show how to use the library. The nice thing about the hd44780 library is that it will autodetect the I2C address and the I2C backpack to LCD pin mapping.