Hi, I'm new in embedded system,I've stm32f100rb and I want to display a string at an lcd named jhd162a 16x2, but when I test it, the lcd always display a black line,I test it with an empty board and it's the same problem, one black line. anyone have an idea please??? and thank you.
lcd_hd44780.c:
#include "lcd_hd44780_lib.h" #include "stm32f10x_gpio.h" #include <stdio.h> #include <string.h> #include <stdlib.h> #include "STM32vldiscovery.h" GPIO_InitTypeDef GPIO_InitStructure; //----------------------------------------------------------------------------- void lcd_writenibble(unsigned char nibbleToWrite) { GPIO_WriteBit(LCD_GPIO, LCD_EN, Bit_SET); GPIO_WriteBit(LCD_GPIO, LCD_D4,(BitAction) (nibbleToWrite & 0x01)); GPIO_WriteBit(LCD_GPIO, LCD_D5,(BitAction)(nibbleToWrite & 0x02)); GPIO_WriteBit(LCD_GPIO, LCD_D6,(BitAction)(nibbleToWrite & 0x04)); GPIO_WriteBit(LCD_GPIO, LCD_D7,(BitAction)(nibbleToWrite & 0x08)); GPIO_WriteBit(LCD_GPIO, LCD_EN, Bit_RESET); } //----------------------------------------------------------------------------- unsigned char LCD_ReadNibble(void) { unsigned char tmp = 0; GPIO_WriteBit(LCD_GPIO, LCD_EN, Bit_SET); tmp |= (GPIO_ReadInputDataBit(LCD_GPIO, LCD_D4) << 0); tmp |= (GPIO_ReadInputDataBit(LCD_GPIO, LCD_D5) << 1); tmp |= (GPIO_ReadInputDataBit(LCD_GPIO, LCD_D6) << 2); tmp |= (GPIO_ReadInputDataBit(LCD_GPIO, LCD_D7) << 3); GPIO_WriteBit(LCD_GPIO, LCD_EN, Bit_RESET); return tmp; } //----------------------------------------------------------------------------- unsigned char LCD_ReadStatus(void) { unsigned char status = 0; GPIO_InitStructure.GPIO_Pin = LCD_D4 | LCD_D5 | LCD_D6 | LCD_D7; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; GPIO_Init(LCD_GPIO, &GPIO_InitStructure); GPIO_WriteBit(LCD_GPIO, LCD_RW, Bit_SET); GPIO_WriteBit(LCD_GPIO, LCD_RS, Bit_RESET); status |= (LCD_ReadNibble() << 4); status |= LCD_ReadNibble(); GPIO_InitStructure.GPIO_Pin = LCD_D4 | LCD_D5 | LCD_D6 | LCD_D7; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(LCD_GPIO, &GPIO_InitStructure); return status; } //----------------------------------------------------------------------------- void lcd_writedata(unsigned char dataToWrite) { GPIO_WriteBit(LCD_GPIO, LCD_RW, Bit_RESET); GPIO_WriteBit(LCD_GPIO, LCD_RS, Bit_SET); lcd_writenibble(dataToWrite >> 4); lcd_writenibble(dataToWrite & 0x0F); while(LCD_ReadStatus() & 0x80); } //----------------------------------------------------------------------------- void lcd_writecommand(unsigned char commandToWrite) { GPIO_WriteBit(LCD_GPIO, LCD_RW | LCD_RS, Bit_RESET); lcd_writenibble(commandToWrite >> 4); lcd_writenibble(commandToWrite & 0x0F); while(LCD_ReadStatus() & 0x80); } //----------------------------------------------------------------------------- void lcd_str(unsigned char * text) { while(*text) lcd_writedata(*text++); } //----------------------------------------------------------------------------- void lcd_locate(unsigned char x, unsigned char y) { lcd_writecommand(HD44780_DDRAM_SET | (x + (0x40 * y))); } //----------------------------------------------------------------------------- void lcd_strxy(unsigned char * text, unsigned char x, unsigned char y) { lcd_locate(x,y); while(*text) lcd_writedata(*text++); } //----------------------------------------------------------------------------- void lcd_writebinary(unsigned int var, unsigned char bitCount) { signed char i; for(i = (bitCount - 1); i >= 0; i--) { lcd_writedata((var & (1 << i))?'1':'0'); } } //----------------------------------------------------------------------------- void LCD_ShiftLeft(void) { lcd_writecommand(HD44780_DISPLAY_CURSOR_SHIFT | HD44780_SHIFT_LEFT | HD44780_SHIFT_DISPLAY); } //----------------------------------------------------------------------------- void LCD_ShiftRight(void) { lcd_writecommand(HD44780_DISPLAY_CURSOR_SHIFT | HD44780_SHIFT_RIGHT | HD44780_SHIFT_DISPLAY); } //----------------------------------------------------------------------------- void lcd_init(void) { volatile unsigned char i = 0; volatile unsigned int delayCnt = 0; RCC_APB2PeriphClockCmd(LCD_CLK_LINE, ENABLE); GPIO_InitStructure.GPIO_Pin = LCD_D4|LCD_D5|LCD_D6|LCD_D7|LCD_RS|LCD_RW|LCD_EN; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(LCD_GPIO, &GPIO_InitStructure); GPIO_ResetBits(LCD_GPIO, LCD_RS | LCD_EN | LCD_RW); for(delayCnt = 0; delayCnt < 300000; delayCnt++); for(i = 0; i < 3; i++) { lcd_writenibble(0x03); for(delayCnt = 0; delayCnt < 30000; delayCnt++); } lcd_writenibble(0x02); for(delayCnt = 0; delayCnt < 6000; delayCnt++); lcd_writecommand(HD44780_FUNCTION_SET | HD44780_FONT5x7 | HD44780_TWO_LINE | HD44780_4_BIT); lcd_writecommand(HD44780_DISPLAY_ONOFF | HD44780_DISPLAY_OFF); lcd_writecommand(HD44780_CLEAR); lcd_writecommand(HD44780_ENTRY_MODE | HD44780_EM_SHIFT_CURSOR | HD44780_EM_INCREMENT); lcd_writecommand(HD44780_DISPLAY_ONOFF | HD44780_DISPLAY_ON | HD44780_CURSOR_OFF | HD44780_CURSOR_NOBLINK); } //----------------------------------------------------------------------------- void lcd_addchar (unsigned char chrNum, unsigned char n, const unsigned char *p) { lcd_writecommand(HD44780_CGRAM_SET | chrNum * 8); n *= 8; do lcd_writedata(*p++); while (--n); } //----------------------------------------------------------------------------- void lcd_cls(void){ lcd_writecommand(HD44780_CLEAR); } unsigned char* intToStr(int n) { int i = 0; char *tmp = (char*)malloc(sizeof(char)); unsigned char *ret = (unsigned char*)malloc(12); if(n < 0) { *ret = '-'; i++; n = -n; } do { *tmp = n % 10 + 48; n -= n % 10; if(n > 9) *tmp++; } while(n /= 10); while(ret[i++] = *tmp--); return ret; } void lcd_int(int n){ lcd_str(intToStr(n)); } void lcd_intxy(int n, unsigned char x, unsigned char y){ lcd_locate(x,y); lcd_str(intToStr(n)); }
main.c
#include <stddef.h> #include "stm32f10x_rcc.h" #include "stm32f10x_gpio.h" #include "lcd_hd44780_lib.h" #include "STM32vldiscovery.h" int main(void) { RCC_PLLConfig (0x00010000, RCC_PLLMul_2); lcd_init(); while (1) { lcd_locate(1,0); lcd_str("ENSI"); lcd_locate(7,0); lcd_str("STM32F1"); lcd_locate(0,1); lcd_str("electronics"); } }