DSP28035驱动的ST7920液晶不能在液晶上显示（并口方式）-hlx3012的回答

DSP28035驱动的ST7920液晶不能在液晶上显示（并口方式）

2019-03-26 16:41发布

各位大侠，你好！
我以C51的并口驱动代码位基础，将其移植到DSP28035上，都调试了一个星期，却仍然无法在显示屏上显示出我要的字符！在LCD的各个引脚上测试的高低电平也没有问题。另外对比度的两个引脚都已经设置为高电平(LCD中的引脚3与引脚18)
请各位大侠指正，万分感谢。

代码中函数如下：
#define  SELECT_INSTRUCTION_REG 0x0000//选择的是写指令寄存器
#define  SELECT_DATA_REG 0x0002 //选择的是写数据寄存器

//片选引脚RS 使能EN 读写RW引脚等的宏
#define LCD_E_EN GpioDataRegs.AIOSET.bit.AIO2 = 1;
#define LCD_E_DIS GpioDataRegs.AIOCLEAR.bit.AIO2 = 1;

#define LCD_RW_EN GpioDataRegs.AIOSET.bit.AIO4 = 1;
#define LCD_RW_DIS GpioDataRegs.AIOCLEAR.bit.AIO4 = 1;

#define LCD_RS_EN GpioDataRegs.AIOSET.bit.AIO6 = 1;
#define LCD_RS_DIS GpioDataRegs.AIOCLEAR.bit.AIO6 = 1;

#define LCD_TR_EN GpioDataRegs.GPBSET.bit.GPIO39 = 1;
#define LCD_TR_DIS GpioDataRegs.GPBCLEAR.bit.GPIO39= 1;

#define LCD_BK_EN GpioDataRegs.GPASET.bit.GPIO21 = 1;
#define LCD_BK_DIS GpioDataRegs.GPACLEAR.bit.GPIO21= 1;

#define LCD_RE_EN GpioDataRegs.GPASET.bit.GPIO20 = 1;
#define LCD_RE_DIS GpioDataRegs.GPACLEAR.bit.GPIO20= 1;

//数据8个引脚的宏
#define LCDPIN_D0_SET GpioDataRegs.GPASET.bit.GPIO0 = 1;
#define LCDPIN_D1_SET GpioDataRegs.GPASET.bit.GPIO1 = 1;
#define LCDPIN_D2_SET GpioDataRegs.GPASET.bit.GPIO2 = 1;
#define LCDPIN_D3_SET GpioDataRegs.GPASET.bit.GPIO3 = 1;
#define LCDPIN_D4_SET GpioDataRegs.GPASET.bit.GPIO4 = 1;
#define LCDPIN_D5_SET GpioDataRegs.GPASET.bit.GPIO5 = 1;
#define LCDPIN_D6_SET GpioDataRegs.GPASET.bit.GPIO6 = 1;
#define LCDPIN_D7_SET GpioDataRegs.GPASET.bit.GPIO7 = 1;

#define LCDPIN_D0_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO0 = 1;
#define LCDPIN_D1_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO1 = 1;
#define LCDPIN_D2_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO2 = 1;
#define LCDPIN_D3_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO3 = 1;
#define LCDPIN_D4_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO4 = 1;
#define LCDPIN_D5_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO5 = 1;
#define LCDPIN_D6_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO6 = 1;
#define LCDPIN_D7_CLEAR GpioDataRegs.GPACLEAR.bit.GPIO7 = 1;

//配置DSP上在LCD中用到的引脚
void SPI_Gpio_select(void)
{
EALLOW;
SysCtrlRegs.WDCR = 0x0068;//禁止看门狗

GpioCtrlRegs.GPBMUX1.bit.GPIO39=0;    //通用IO(LCD背光灯）
GpioCtrlRegs.GPBDIR.bit.GPIO39 =1; //输出
GpioCtrlRegs.GPBPUD.bit.GPIO39 =0;    //禁止上拉电阻

GpioCtrlRegs.GPAMUX2.bit.GPIO20=0;    //通用IO(片选CS管脚)
GpioCtrlRegs.GPADIR.bit.GPIO20 =1; //输出
GpioCtrlRegs.GPAPUD.bit.GPIO20 =0; //禁止上拉电阻

GpioCtrlRegs.GPAMUX2.bit.GPIO21=0; //数据管脚SPISIMO
GpioCtrlRegs.GPADIR.bit.GPIO21 =1;    //输出
GpioCtrlRegs.GPAPUD.bit.GPIO21 =0;

GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO1 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO2 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO3 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO4 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO5 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO6 = 1;
GpioCtrlRegs.GPADIR.bit.GPIO7 = 1;

EDIS;
}

//延时
void F_delay(Uint16 D_time)
{
Uint16 i=0;
for(i=0;i<D_time;i++);
}

//写指令或者数据
void send_data(Uint16 D_Ctrl,Uint16 D_data)
{
Uint16 i=0,temp=0;

//#if PARALLEL_8_BIT_MODE//8位一起发送

//checkBF（）；//测试BF位是否忙

if(D_Ctrl == SELECT_INSTRUCTION_REG)//写指令到LCD
{
LCD_RS_DIS;
}
else if(D_Ctrl == SELECT_DATA_REG)//写数据到LCD
{
LCD_RS_EN;
}

LCD_RW_DIS;
LCD_E_EN;
F_delay(100);

if(D_data & 0x01){LCDPIN_D0_SET;}else{LCDPIN_D0_CLEAR;};
if(D_data & 0x02){LCDPIN_D1_SET;}else{LCDPIN_D1_CLEAR;};
if(D_data & 0x04){LCDPIN_D2_SET;}else{LCDPIN_D2_CLEAR;};
if(D_data & 0x08){LCDPIN_D3_SET;}else{LCDPIN_D3_CLEAR;};
if(D_data & 0x10){LCDPIN_D4_SET;}else{LCDPIN_D4_CLEAR;};
if(D_data & 0x20){LCDPIN_D5_SET;}else{LCDPIN_D5_CLEAR;};
if(D_data & 0x40){LCDPIN_D6_SET;}else{LCDPIN_D6_CLEAR;};
if(D_data & 0x80){LCDPIN_D7_SET;}else{LCDPIN_D7_CLEAR;};

LCD_E_DIS;
F_delay(100);
LCD_RW_EN;
if(D_Ctrl == SELECT_INSTRUCTION_REG)//写指令到LCD
{
LCD_RS_EN;
}
else if(D_Ctrl == SELECT_DATA_REG)//写数据到LCD
{
LCD_RS_DIS;
}
F_delay(100);
}

//LCD初始化
void LCD_Initial(void)
{

LOG_printf(&trace,"LCD_Initial come here ");

//复位操作:RST出现一个上升沿(RST = 1;RST = 0;RST = 1)
GpioDataRegs.GPASET.bit.GPIO20 = 1;
//延时
F_delay(10000);
GpioDataRegs.GPACLEAR.bit.GPIO20 = 1;
//延时
F_delay(10000);
GpioDataRegs.GPASET.bit.GPIO20 = 1;
//延时
F_delay(1000);

//显示状态开关
   send_data(SELECT_INSTRUCTION_REG,0x0008);
LOG_printf(&trace,"0x0008 ");
F_delay(120);
//功能设定
   send_data(SELECT_INSTRUCTION_REG,0x0030); //功能设定，8位控制模式
LOG_printf(&trace,"0x0030 ");
//延时
F_delay(120);
//再次功能设定
send_data(SELECT_INSTRUCTION_REG,0x0030); //功能设定，8位控制模式
LOG_printf(&trace,"0x0030 ");
//延时
F_delay(120);
//显示开关控制(整体显示关,游标显示关，正常显示(游标位置没有反白))
send_data(SELECT_INSTRUCTION_REG,0x000C);
LOG_printf(&trace,"0x000c ");
//延时
F_delay(120);
//清除显示
send_data(SELECT_INSTRUCTION_REG,0x0001);
LOG_printf(&trace,"0x0001 ");
//延时
F_delay(10000);
//进入点设置(游标右移，DDRAM位地址加1，画面不移动)
//串口中将此进入点设置给屏蔽掉了，待调试中再做决定
send_data(SELECT_INSTRUCTION_REG,0x06);
LOG_printf(&trace,"0x0006 ");
//延时
F_delay(120);
//显示开关控制(开显示)
send_data(SELECT_INSTRUCTION_REG,0x000C);
LOG_printf(&trace,"0x000c ");
F_delay(120);

//地址归位
send_data(SELECT_INSTRUCTION_REG,0x02);
F_delay(120);

//设定DDRAM
send_data(SELECT_INSTRUCTION_REG,0x80);
F_delay(120);

}

//LCD任务
void LcdTask(void)
{
int i = 0;

GpioDataRegs.GPACLEAR.bit.GPIO21 = 1; //背光灯
g_StateCheck.bit.Start_Stage00 = 0;
GpioDataRegs.GPBSET.bit.GPIO39 =1;
SPI_Gpio_select(); //SPI管脚配置
LCD_Initial(); //LCD初始化
F_delay(10000);

for(;;)
{
send_data(SELECT_INSTRUCTION_REG,0x84);//设定显示地址为首行首列
send_data(SELECT_DATA_REG,0x34);
send_data(SELECT_DATA_REG,0xD2);
send_data(SELECT_DATA_REG,0xBA);//显示"液"
send_data(SELECT_DATA_REG,0xBE);
send_data(SELECT_DATA_REG,0xA6);//显示"晶"
}
} 此帖出自小平头技术问答

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3条回答

hlx3012

2019-03-27 02:22

ST7920的高电平确认是5V还是3.3V？

首先想想办法让液晶屏显示点什么，查查看时序对不对，液晶屏要求的时钟信号会不会比你给的慢

[ 本帖最后由 hlx3012 于 2012-3-28 19:42 编辑 ]

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