探秘NHD - 0420H1Z - FSW - GBW - 3V3字符液晶显示模块

一、模块概述

NHD - 0420H1Z - FSW - GBW - 3V3是Newhaven Display International推出的一款字符液晶显示模块。从其型号就能获取不少关键信息：“0420”表明该模块有4行，每行可显示20个字符；“H1Z”代表特定型号；“F”意味着它是半透反射型；“SW”表示采用侧面白色LED背光；“G”代表STN - 灰度；“B”是6:00视角；“W”说明具备宽温度范围（ - 20°C到 + 70°C）；“3V3”则表示逻辑电源和背光电源均为3.3V，并且该模块符合RoHS标准。

文件下载：NHD-0420H1Z-FSW-GBW-3V3.pdf

二、功能与特性

显示规格

该模块拥有4行×20字符的显示能力，能满足一般信息显示需求。

内置控制器

内置SPLC780D或ST7066U控制器，可通过链接http://www.newhavendisplay.com/app_notes/SPLC780D.pdf和http://www.newhavendisplay.com/app_notes/ST7066U.pdf下载其详细规格。

电源与电气特性

采用 + 3.0V电源供电，工作在1/16 duty、1/4 bias模式，且符合RoHS标准。

三、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 (+3.3V)
3	V0	Power Supply	Power supply for contrast (approx. 0.3V)
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. 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	Power supply for LED Backlight (+3.3V)
16	LED -	Power Supply	Ground for backlight

推荐使用2.54mm间距的引脚作为LCD连接器。

四、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	3.5	V
Supply Current	IDD	Ta = 25°C, VDD = 3.3V	-	4.0	5.0	mA
Supply for LCD (contrast)	VDD - V0	Ta = 25°C	-	3.0	-	V
“H” Level input	Vih		2.2	-	VDD	V
“L” Level input	Vil		0	-	0.6	V
“H” Level output	Voh		2.4	-	-	V
“L” Level output	Vol		-	-	0.4	V
Backlight Supply Voltage	Vled	-	-	3.3	-	V
Backlight Supply Current	Iled	Vled = 3.3V	-	12	-	mA

光学特性

Item	Symbol	Condition	Min.	Typ.	Max.	Unit
Viewing Angle – Vertical (top)	AV	Cr ≥2	-	25	-	⁰
Viewing Angle – Vertical (bottom)	AV	Cr ≥2	-	70	-	⁰
Viewing Angle – Horizontal (left)	AH	Cr ≥2	-	30	-	⁰
Viewing Angle – Horizontal (right)	AH	Cr ≥2	-	30	-	⁰
Contrast Ratio	Cr		-	2	-	-
Response Time (rise)	Tr	-	-	120	150	ms
Response Time (fall)	Tf	-	-	120	150	ms

五、初始化程序

8位初始化

/**********************************************************/
void command(char i)
{
    P1 = i;
    D_I = 0; //D/I = LOW : send instruction
    R_W = 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;
    D_I = 1; //D/I = HIGH : send data
    R_W = 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 >15 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);
    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;
    D_I = 0; //D/I = LOW : send instruction
    R_W = 0; //R/W = LOW : Write
    Nybble(); //Send lower 4 bits
    i = i < < 4; //Shift over by 4 bits
    P1 = i;
    Nybble(); //Send upper 4 bits
}
/**********************************************************/
void write(char i)
{
    P1 = i;
    D_I = 1; //D/I = HIGH : send data
    R_W = 0; //R/W = LOW:Write
    Nybble(); //Clock lower 4 bits
    i = i < < 4; //Shift over by 4 bits
    P1 = i;
    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;
    E = 0;
    Delay(100); //Wait >15 msec after power is applied
    P1 = 0x30;
    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);
    P1 = 0x20;
    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、质量信息与注意事项

质量测试

Test Item	Content of Test	Test Condition	Note
High Temperature storage	Endurance test applying the high storage temperature for a long time.	+80⁰C , 48hrs	2
Low Temperature storage	Endurance test applying the low storage temperature for a long time.	- 30⁰C , 48hrs	1,2
High Temperature Operation	Endurance test applying the electric stress (voltage & current) and the high thermal stress for a long time.	+70⁰C 48hrs	2
Low Temperature Operation	Endurance test applying the electric stress (voltage & current) and the low thermal stress for a long time.	- 20⁰C , 48hrs	1,2
High Temperature / Humidity Operation	Endurance test applying the electric stress (voltage & current) and the high thermal with high humidity stress for a long time.	+40⁰C , 90% RH , 48hrs	1,2
Thermal Shock resistance	Endurance test applying the electric stress (voltage & current) during a cycle of low and high thermal stress.	0⁰C,30min -> 25⁰C,5min -> 50⁰C,30min = 1 cycle 10 cycles
Vibration test	Endurance test applying vibration to simulate transportation and use.	10 - 55Hz , 15mm amplitude. 60 sec in each of 3 directions X,Y,Z For 15 minutes	3
Static electricity test	Endurance test applying electric static discharge.	VS = 800V, RS = 1.5kΩ, CS = 100pF One time

注意事项

使用该模块时，需注意无冷凝现象，部分测试需在25⁰C、0%RH环境下存储4小时后进行，振动测试在产品本身而非容器内进行。同时，可访问www.newhavendisplay.com/specs/precautions.pdf查看使用LCD/LCM的预防措施，保修信息和条款可查看http://www.newhavendisplay.com/index.php?main_page=terms 。

各位电子工程师在使用这款模块时，是否有遇到过一些特殊的问题呢？不妨在评论区分享交流。