Newhaven NHD - 0220AZ - FL - GBW液晶显示模块深度解析

引言

在电子设备中，液晶显示模块是人机交互的重要组成部分。Newhaven Display International推出的NHD - 0220AZ - FL - GBW字符液晶显示模块，以其出色的性能和广泛的适用性，受到了众多电子工程师的青睐。本文将对该模块进行详细的技术剖析，帮助工程师们更好地了解和使用这款产品。

文件下载：NHD-0220AZ-FL-GBW.pdf

产品概述

产品型号解析

NHD - 0220AZ - FL - GBW这个型号包含了丰富的信息：

• “NHD - ”代表Newhaven Display。
• “0220 - ”表示该模块具有2行，每行20个字符的显示能力。
• “AZ - ”为具体的型号标识。
• “F - ”表明采用了半透反射技术。
• “L - ”代表黄/绿色LED背光。
• “G - ”表示STN - 灰色显示。
• “B - ”意味着具有6:00视角。
• “W - ”表示宽温度范围（ - 20°C~ + 70°C），并且该产品符合RoHS标准。

功能与特性

• 显示能力：具备2行×20字符的显示能力，能够清晰地呈现文本信息。
• 内置控制器：内置SPLC780D或等效控制器，方便进行显示控制。
• 电源供应：采用 + 5.0V电源供应，同时具有1/16 duty和1/5 bias的特性。

机械与电气特性

引脚描述与接线图

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. 0.4V)
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	Power supply for LED Backlight (+5.0V via on - board resistor)
16	LED -	Power Supply	Ground for Backlight

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		4.7	5.0	5.5	V
Supply Current	IDD	Ta = 25°C, VDD = 5.0V	-	1.5	2.5	mA
Supply for LCD (contrast)	VDD - V0	Ta = 25°C	-	4.6	-	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	-	-	5.0	-	V
Backlight Supply Current	Iled	Vled = 5.0V	-	150	300	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

控制器信息与指令表

控制器

内置SPLC780D控制器，其详细规格可从http://www.newhavendisplay.com/app_notes/SPLC780D.pdf下载。

指令表

该模块提供了一系列指令，用于控制显示、光标等操作，以下是部分指令示例：	Instruction	RS	R/W	DB7	DB6	Instruction Code	DB5	DB4	DB3	DB2	DB1	DBO	Description	Execution time (fosc = 270KHz)
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

时序特性

写入模式

Characteristics	Symbol	Limit	Unit	Test Condition
Min.	Typ.	Max.
E Cycle Time	to	500			ns	An E
E Pulse Width	tW	230			ns	Pin E
E Rise/Fall Time	tR.tF			20	ns	Pin E
Address Setup Time	tsP1	40			ns	Pins: RS, RW, E
Address Hold Time	HD1	10			ns	Pins: RS, RW, E
Data Setup Time	tsP2	80			ns	Pins: DB0 - DB7
Data Hold Time	HD2	10			ns	Pins: DB0 - DB7

读取模式

Characteristics	Symbol	Limit	Unit	Test Condition
Min.	Typ.	Max.
E Cycle Time	to	500			ns	Pin E
E Pulse Width	tW	230			ns	Pin E
E Rise/Fall Time	tR.tF			20	ns	Pin E
Address Setup Time	tsp				Pins: RS, RW, E
Address Hold Time	40				Pins: RS, RW, E
Data Setup Time	to		120
Data Hold Time		5.0			ns	An DB0 - DB7

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
    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) {
    E = 0;
    P1 = i; //put data on output Port
    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); //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
    R_W = 0; //R/W = LOW:Write
    Nybble(); //Send lower 4 bits
    i = i < < 4; //Shift over by 4 bits
    P1 = i; //put data on output Port
    Nybble(); //Send upper 4bits
}

void write(char i) {
    P1 = i; //put data on output Port
    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; //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); //Wait >15 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); 
    command(0x0F); //Set cursor
    command(0x0F); //Display ON; Blinking cursor
    command(0x06); //Entry Mode set
}

质量与使用注意事项

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

使用注意事项

使用LCDs/LCMs时的具体注意事项可参考www.newhavendisplay.com/specs/precautions.pdf。同时，关于保修信息和条款可访问http://www.newhavendisplay.com/index.php?main_page=terms 。

总结

Newhaven NHD - 0220AZ - FL - GBW字符液晶显示模块在显示能力、电气特性、光学特性等方面都表现出色。通过对其引脚、指令、时序特性以及初始化程序的了解，工程师们可以更好地将其应用到实际项目中。在使用过程中，遵循质量测试和使用注意事项，能够确保模块的稳定运行。大家在实际应用中是否遇到过类似模块的问题呢？欢迎在评论区分享交流。