NHD-0220FZ-FSW-GBW-P-33V3字符液晶显示模块技术解析

一、模块概述

NHD - 0220FZ - FSW - GBW - P - 33V3是Newhaven Display International, Inc.生产的一款字符液晶显示模块。从其型号可以解读出丰富的信息：

文件下载：NHD-0220FZ-FSW-GBW-P-33V3.pdf

• “NHD - ”代表Newhaven Display。
• “0220 - ”表示该模块为2行×20字符的显示规格。
• “FZ - ”是特定的型号标识。
• “F - ”代表半透反射型。
• “SW - ”表示侧面白色LED背光。
• “B - ”意味着6:00最佳视角。
• “W - ”代表宽温度范围。
• “P - ”表示引脚已焊接。
• “33V3 - ”表示3.3V的VDD电源和3.0V的背光电源，并且该模块符合RoHS标准。

二、功能与特性

显示规格

该模块具有2行×20字符的显示能力，内置ST7066U控制器，采用+3.3V电源供电，工作模式为1/16 duty，1/5 bias。

引脚分配

详细的引脚分配如下表所示：	Pin No.	Symbol	External Connection	Function Description
1	VSS	Power Supply	Ground
2	VDD	Power Supply	Supply Voltage for logic (+3.3V)
3	V0	Adj. Power Supply	Supply Voltage for contrast (approx. 0 V)
4	RS	MPU	Register Select signal. RS = 0: Command, RS = 1: Data
5	R/W	MPU	Read/Write select signal, R/W = 1: Read R/W: = 0: Write
6	E	MPU	Operation Enable signal. Falling edge triggered.
7 - 10	DB0 – DB3	MPU	Four low order bi - directional three - state data bus lines. These four are not used during 4 - bit operation.
11 - 14	DB4 – DB7	MPU	Four high order bi - directional three - state data bus lines.
15	LED+	Power Supply	Backlight Anode (15mA @3V)
16	LED -	Power Supply	Backlight Cathode (Ground)
17	VSS
18	VDD
19	V0
20	RS
21	RW
22	E
23 - 26	DB4 - DB7
27	LED+
28	LED -

推荐使用1.27mm间距的引脚作为LCD连接器。

三、电气与光学特性

电气特性

Item	Symbol	Condition	Min.	Typ.	Max.	Unit
Operating Temperature Range	TOP	Absolute Max	- 20	-	+70	⁰C
Storage Temperature Range	TST	Absolute Max	- 30	-	+80	⁰C
Supply Voltage	VDD	-	3.0	3.3	3.6	V
Supply Current	IDD	VDD = 3.3V	0.5	1.0	2.0	mA
Supply for LCD (contrast)	VLCD	TOP = 25°C	3.1	3.3	3.5	V
“H” Level input	VIH	-	0.7 * VDD	-	VDD	V
“L” Level input	VIL	-	VSS	-	0.6	V
“H” Level output	VOH	-	0.75 * VDD	-	VDD	V
“L” Level output	VOL	-	VSS	-	0.2 * VDD	V
Backlight Supply Voltage	VLED	-	2.8	3.0	3.2	V
Backlight Supply Current	ILED	VLED = 3.0V	7	15	20	mA

光学特性

Item		Symbol	Condition	Min.	Typ.	Max.	Unit
Optimal Viewing Angles	Top	ϕY+	CR ≥ 2	-	40	-	°
	Bottom	ϕY -	-	60	-	°
	Left	θX -	-	60	-	°
	Right	θX+	-	60	-	°
Contrast Ratio		CR	-	2	5	-
Response Time	Rise	TR	TOP = 25°C	-	150	250	ms
	Fall	TF	-	200	300	ms

四、控制器与指令

控制器信息

模块内置ST7066U控制器，详细的规格说明可从http://www.newhavendisplay.com/app_notes/ST7066U.pdf下载。

指令集

模块提供了丰富的指令集，用于控制显示操作，例如清屏、光标移动、显示开关等。以下是部分指令示例：	Instruction	Instruction code	Description	270 KHZ Execution time (fosc = )
Clear Display	0 0 0 0 0 0 0 0 0 1	Write “20H” to DDRAM and set DDRAM address to “00H” from AC	1.52ms
Return Home	0 0 0 0 0 0 0 0 1 -	Set DDRAM Address to “00H” from AC and return cursor to its original position if shifted. The contents of DDRAM are not changed.	1.52ms
Entry mode Set	0 0 0 0 0 0 0 1 I/D SH	Sets cursor move direction and specifies display shift. These parameters are performed during data write and read.	37µs

五、初始化程序

8位初始化

/**********************************************************/
void command(char i) 
{ 
    P1 = i; //put data on output Port 
    D_I = 0; //D/I = LOW : send instruction 
    RW = 0; //R/W = LOW: Write
    E = 1; 
    Delay(1); //enable pulse width >= 300ns 
    E = 0; //Clock enable: falling edge 
}

void write(char i) 
{
    P1 = i; //put data on output Port 
    D_I = 1; //D/I = HIGH : send data 
    RW = 0; //R/W = LOW : Write 
    E = 1; 
    Delay(1); //enable pulse width >= 300ns 
    E = 0; //Clock enable: falling edge 
}

void init() 
{
    E = 0; 
    Delay(100); //Wait >40 msec after power is applied 
    command(0x30); //command 0x30 = Wake up 
    Delay(30); //must wait 5ms, busy flag not available 
    command(0x30); //command 0x30 = Wake up #2 
    Delay(10); //must wait 160us, busy flag not available 
    command(0x30); //command 0x30 = Wake up #3 
    Delay(10); //must wait 160us, busy flag not available 
    command(0x38); //Function set: 8 - bit/2 - line 
    command(0x10); //Set cursor
    command(0x0c); //Display ON; Cursor ON 
    command(0x06); //Entry mode set 
}
/**********************************************************/

4位初始化

/**********************************************************/
void command(char i) 
{
    P1 = i; //put data on output Port 
    D_I = 0; //D/I = LOW : send instruction 
    RW = 0; 
    Nybble(); //Send upper 4 bits 
    i = i < < 4; //Shift over by 4 bits 
    P1 = i; //put data on output Port 
    Nybble(); //Send lower 4 bits 
}

void write(char i) 
{
    P1 = i; //put data on output Port 
    D_I = 1; //D/I = HIGH : send data 
    RW = 0; 
    Nybble(); //Clock upper 4 bits 
    i = i < < 4; //Shift over by 4 bits 
    P1 = i; //put data on output Port 
    Nybble(); //Clock lower 4 bits 
}

void Nybble() 
{
    E = 1; 
    Delay(1); //enable pulse width >= 300ns 
    E = 0; //Clock enable: falling edge 
}

void init() 
{
    P1 = 0; P3 = 0; 
    Delay(100); //Wait >40 msec after power is applied 
    P1 = 0x30; //put 0x30 on the output port 
    Delay(30); //must wait 5ms, busy flag not available 
    Nybble(); //command 0x30 = Wake up 
    Delay(10); //must wait 160us, busy flag not available 
    Nybble(); //command 0x30 = Wake up #2 
    Delay(10); //must wait 160us, busy flag not available 
    Nybble(); //command 0x30 = Wake up #3 
    Delay(10); //can check busy flag now instead of delay 
    P1 = 0x20; //put 0x20 on the output port 
    Nybble(); //Function set: 4 - bit interface 
    command(0x28); //Function set: 4 - bit/2 - line 
    command(0x10); //Set cursor
    command(0x0F); //Display ON; Blinking cursor 
    command(0x06); //Entry Mode set 
}
/**********************************************************/

六、质量与使用注意事项

质量测试

该模块经过了多项质量测试，包括高温存储、低温存储、高温运行、低温运行、高温高湿运行、热冲击抗性、振动测试和静电测试等，以确保其在不同环境下的可靠性。

使用注意事项

使用LCD/LCM时的详细注意事项可在www.newhavendisplay.com/specs/precautions.pdf查看。同时，保修信息和条款可访问http://www.newhavendisplay.com/index.php?main_page=terms 。

在实际应用中，电子工程师可以根据这些特性和参数，合理地将NHD - 0220FZ - FSW - GBW - P - 33V3模块集成到自己的项目中。你在使用这款模块时，有没有遇到过一些特殊的问题呢？欢迎在评论区分享。