LCD16x2
===========================
LCD16x2 is a popular display module and commonly used in various devices.
In this tutorial, I will explain about how to use LCD16x2 with STM32F103 microcontroller.
To interface the LCD with STM32F103, you need the library files (lcd16x2.h and lcd16x2.c).
You can get the library files and from [here](https://github.com/yohanes-erwin/stm32f103-keil/tree/master/lcd16x2).
LCD16x2 Library
===========================
In this library, we can configure the GPIO for LCD in lcd16x2.h file.
This definitions (in source code below) in lcd16x2.h contain the GPIO configuration for the LCD.
In this definitions, you can configure the GPIO for LCD control lines (RS, RW, EN) and LCD data lines (D4-D7).
This library only support 4-bit data mode.
~~~~~~~~~~~~~~~~~~~~~~~~~~~ C linenumbers
// LCD control lines (must be on the same port)
#define LCD16X2_RCC_GPIO_CONTROL RCC_APB2Periph_GPIOB
#define LCD16X2_GPIO_CONTROL GPIOB
#define LCD16X2_GPIO_RS GPIOB
#define LCD16X2_GPIO_RW GPIOB
#define LCD16X2_GPIO_EN GPIOB
// LCD data lines (must be on the same port)
#define LCD16X2_RCC_GPIO_DATA RCC_APB2Periph_GPIOA
#define LCD16X2_GPIO_DATA GPIOA
#define LCD16X2_GPIO_D4 GPIOA
#define LCD16X2_GPIO_D5 GPIOA
#define LCD16X2_GPIO_D6 GPIOA
#define LCD16X2_GPIO_D7 GPIOA
// Pin definition
#define LCD16X2_PIN_RS GPIO_Pin_12
#define LCD16X2_PIN_RW GPIO_Pin_13
#define LCD16X2_PIN_EN GPIO_Pin_14
#define LCD16X2_PIN_D4 GPIO_Pin_8 // 4-bit mode LSB
#define LCD16X2_PIN_D5 GPIO_Pin_9
#define LCD16X2_PIN_D6 GPIO_Pin_10
#define LCD16X2_PIN_D7 GPIO_Pin_11 // 4-bit mode MSB
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Example Code
===========================
To use this library, in the main.c file, you must call lcd16x2_init() function.
There are 5 parameters for this function that can be used, depending on what type of cursor you want to use:
* LCD16X2_DISPLAY_OFF_CURSOR_OFF_BLINK_OFF
* LCD16X2_DISPLAY_ON_CURSOR_OFF_BLINK_OFF
* LCD16X2_DISPLAY_ON_CURSOR_OFF_BLINK_ON
* LCD16X2_DISPLAY_ON_CURSOR_ON_BLINK_OFF
* LCD16X2_DISPLAY_ON_CURSOR_ON_BLINK_ON
This library is also support custom character display.
This code below is an example how to use the library for displaying a string and also a custom character.
The custom character is created by defining the pattern.
In this example, I use the pattern for battery indicator.
~~~~~~~~~~~~~~~~~~~~~~~~~~~ C linenumbers
#include "stm32f10x.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_gpio.h"
#include "delay.h"
#include "lcd16x2.h"
// Custom char data (battery symbol)
uint8_t custom_char[] = { 0x0E, 0x1B, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x1F };
int main(void)
{
// Delay initialization
DelayInit();
// LCD initialization
lcd16x2_init(LCD16X2_DISPLAY_ON_CURSOR_OFF_BLINK_OFF);
// Create custom char
lcd16x2_create_custom_char(0, custom_char);
while (1)
{
// Display custom char
lcd16x2_put_custom_char(0, 0, 0);
lcd16x2_puts(" Battery Low");
DelayMs(500);
// Clear display
lcd16x2_clrscr();
DelayMs(500);
}
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is the result:
