字符液晶显示模块NHD - 0212WH - AYYH - JT产品解析

一、产品概述

NHD - 0212WH - AYYH - JT是Newhaven Display International, Inc.推出的一款字符液晶显示模块。该模块具有2行12字符的显示能力，内置ST7066U控制器，采用+5.0V电源供电，具备1/16 duty、1/5 bias的特性，并且符合RoHS标准。

文件下载：NHD-0212WH-AYYH-JT#.pdf

二、产品关键参数与特性

（一）引脚说明与接线图

Pin No.	Symbol	External Connection	Function Description
1	VSS	Power Supply	Ground
2	VDD	Power Supply	Supply Voltage for logic (+5.0V)
3	V0	Adj Power Supply	Power supply for contrast (approx. 0.8V)
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	A	Power Supply	Power supply for LED Backlight (+4.2V)

推荐的LCD连接器为1.27mm间距引脚，不过文档中未提及背光连接器的适配信息。

（二）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		4.5	5.0	5.5	V
Supply Current	IDD	Ta = 25°C, VDD = 5.0V	0.5	1.0	2.0	mA
Supply for LCD (contrast)	VDD - V0	Ta = 25°C	4.1	4.2	4.3	V
“H” Level input	Vih		0.7*VDD	-	VDD	V
“L” Level input	Vil		VSS	-	0.6	V
“H” Level output	Voh		3.9	-	VDD	V
“L” Level output	Vol		0	-	0.4	V
Backlight Supply Voltage	Vled	-	4.0	4.2	4.7	V
Backlight Supply Current	Iled	Vled = 4.2V	32	40	48	mA

（三）光学特性

Item	Symbol	Condition	Min.	Typ.	Max.	Unit
Viewing Angle – Top		Cr ≥ 2	-	20	-	⁰
Viewing Angle – Bottom		-	40	-	⁰
Viewing Angle – Left		-	30	-	⁰
Viewing Angle – Right		-	30	-	⁰
Contrast Ratio	Cr		-	3	-	-
Response Time (rise)	Tr	-	-	150	200	ms
Response Time (fall)	Tf	-	-	150	200	ms

三、指令集与时序特性

（一）指令表

该模块提供了丰富的指令集，用于控制显示、光标等操作。例如：	Instruction	Instruction code	Description	270 KHZ Execution time (fosc = )
Clear Display	0 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 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

（二）时序特性

1. 写数据（MPU到ST7066U）
   • Enable Cycle Time (Tc)：1200ns
   • Enable Pulse Width (TPW)：460ns
   • Enable Rise/Fall Time (TR, TF)：最大25ns
   • Address Setup Time (TAS)：0ns
   • Address Hold Time (TAH)：10ns
2. 读数据（ST7066U到MPU）
   • Enable Cycle Time (Tc)：1200ns
   • Enable Pulse Width (TPW)：480ns
   • Enable Rise/Fall Time (TR, TF)：25ns
   • Address Setup Time (TAS)：0ns
   • Address Hold Time (TAH)：10ns
   • Data Setup Time (TDDR)：320ns
   • Data Hold Time (TH)：10ns

四、初始化程序

（一）8位初始化

void command(char i)
{
    P1 = i; D1 = 0; R_W = 0; //put data on output Port //D/I = LOW: send instruction //R/W - LOW: Write
    E = 1;
    Delay(1); //enable pulse width >= 300ns
    E = 0; //Clock enable: falling edge
}

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

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

（二）4位初始化

void command(char i)
{
    P1 = i; //put data on output Port
    D1 = 0; //D/I = LOW : send instruction
    R_W = 0; Nybble(); //R/W - LOW: Write //Send lower 4 bits
    i = i < < 4; P1 = i; Nybble(); //put data on output Port //Send upper 4 bits //Shift over by 4 bits
}

void write(char i)
{
    P1 = i; Dl = 1; RW = 0; //put data on output Port //D/I = HIGH: send data //R/W - LOW: Write
    Nybble(); i = i < < 4; P1 = i; //Clock lower 4bits //Shift over by 4 bits //put data on output Port
    Nybble(); //Clock upper 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); P1 = 0x30; //Wait >40 msec after power is applied //put 0x30 on the output port
    Delay(30); Nybble(); //must wait 5ms, busy flag not available //command 0x30 = Wake up
    Delay(10); Nybble(); //command 0x30 = Wake up #2 //must wait 160us, busy flag not available
    Nybble(); Nybble(); Delay(10); command(0x28); Delay(10); command(0x06); command(0x0F); P1 = 0x20; command(0x10); 
    //can check busy flag now instead of delay //command 0x30 = Wake up #3 //put 0x20 on the output port //must wait 160us, busy flag not available //Function set: 4 - bit interface //Function set: 4 - bit/2 - line //Set cursor //Entry Mode set //Display ON; Blinking cursor
}

五、质量信息

该模块进行了多项质量测试，包括高低温存储、高低温操作、高温高湿操作、热冲击抵抗、振动测试和静电测试等。例如，高温存储测试在+80⁰C下进行48小时，低温存储测试在 - 30⁰C下进行48小时。这些测试确保了模块在不同环境条件下的可靠性。

六、总结

NHD - 0212WH - AYYH - JT字符液晶显示模块具有丰富的功能和良好的性能，适用于多种需要字符显示的应用场景。电子工程师在设计使用该模块时，需要充分了解其引脚功能、电气特性、指令集和时序要求，合理进行初始化编程，以确保模块正常工作。同时，通过质量测试信息可以对模块的可靠性有更深入的了解，从而更好地应用于实际项目中。大家在使用过程中有没有遇到过类似模块的一些特殊问题呢？欢迎在评论区分享交流。