I am trying to display text on the CN0296D LCD display from a microcontroller.
I wonder if there is a manual describing the I2C-interface? Should I send ASCII characters? Are there escape sequences for clearing the screen etc?
1.This is the datasheet:
http://wiki.sunfounder.cc/images/1/18/PCF8574T_datasheet.pdf
2.Yes, you typically need to send ASCII characters to the LCD display. The characters are converted into corresponding graphics displayed on the screen.
3.Common Commands:
Here are some common control commands:
Initialization: The LCD needs to be initialized at the start.
Clear Screen: Sending the command 0x01 can clear the screen.
Return to Main Menu: Sending the command 0x02 can return the cursor to the starting position.
Set Cursor Position:
For the n-th column of the first row: 0x80 + n
For the n-th column of the second row: 0xC0 + n
Write Data: Send the corresponding value of the ASCII character.
Here is a simple pseudocode example showing how to send characters and commands to a 2004 LCD via I2C:
// Assume there is a function to send data via I2C
void sendCommand(uint8_t command) {
// Send command to LCD
}
void sendData(char data) {
// Send data to LCD
}
void setup() {
// Initialize LCD
sendCommand(0x38); // Set to 8-bit mode
sendCommand(0x0C); // Turn on display, no cursor
sendCommand(0x01); // Clear screen
}
void loop() {
sendData(‘H’);
sendData(‘e’);
sendData(‘l’);
sendData(‘l’);
sendData(‘o’);
}
Explanation:
sendCommand: This function sends command instructions to the LCD.
sendData: This function sends character data to be displayed on the LCD.
setup: Initializes the LCD with specific settings.
0x38: Configures the LCD to run in 8-bit mode.
0x0C: Turns on the display without showing the cursor.
0x01: Clears the display.
loop: Continuously sends the characters ‘H’, ‘e’, ‘l’, ‘l’, ‘o’ to the LCD.
Thank you, but I need more than that.
I have found code on github, GitHub - Ckath/lcd2004_i2c: simple i2c-dev lib for interfacing with lcd2004 displays on linux, that sends a character in the upper four bits of two bytes. I suppose that was needed when there was no I2C interface or is it still needed? How do you separate commands from text?
You mentioned 0x38 to set 8-bit mode, that is different from what is used in the code mentioned:
#define LCD_8BITMODE 0x10.
A manual for the LCD with the I2C interface would be very useful, I have only got the PCF8574 document from you.
Thank you.
I have found more details on https://www.handsontec.com/dataspecs/I2C_2004_LCD.pdf and http://www.liquidcrystaltechnologies.com/PDF/ks0066.pdf.