NHD字符液晶顯示模塊產(chǎn)品規(guī)格解析
在電子設(shè)備中,液晶顯示模塊是不可或缺的人機(jī)交互界面。今天,我們來深入了解一下Newhaven Display International推出的NHD字符液晶顯示模塊,它的各項(xiàng)特性和技術(shù)細(xì)節(jié)對于電子工程師在設(shè)計(jì)相關(guān)產(chǎn)品時(shí)具有重要的參考價(jià)值。
一、產(chǎn)品概述
NHD字符液晶顯示模塊具有2行8字符的顯示能力,內(nèi)置ST7066U控制器,采用+5.0V電源供電,具備1/16 duty、1/5 bias的驅(qū)動(dòng)特性,并且符合RoHS標(biāo)準(zhǔn),環(huán)保又可靠。
二、關(guān)鍵技術(shù)參數(shù)
(一)機(jī)械設(shè)計(jì)
| 從機(jī)械圖紙來看,該模塊的各引腳都有明確的定義和作用。標(biāo)準(zhǔn)公差為線性±0.3mm,尺寸以毫米為單位,采用第三角度投影。其引腳分配如下: | 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 | Supply Voltage for contrast (approx. 0.6V) | |
| 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. | |
| A | NC | - | No Connect | |
| K | NC | - | No Connect |
推薦使用2.54mm間距的引腳作為LCD連接器。大家在進(jìn)行機(jī)械設(shè)計(jì)時(shí),一定要嚴(yán)格按照這些參數(shù)來布局,避免出現(xiàn)引腳連接錯(cuò)誤等問題。
(二)電氣特性
| 電氣特性決定了模塊的工作范圍和穩(wěn)定性,以下是具體參數(shù): | Item | Symbol | Condition | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|---|---|
| Operating Temperature Range | TOP | Absolute Max | -20 | - | +70 | ?C | |
| Storage Temperature Range | TST | Absolute Max | -30 | - | +80 | ?C | |
| Supply Voltage | VDD | - | 4.8 | 5.0 | 5.2 | V | |
| Supply Current | IDD | VDD = 5.0V | 0.5 | 1.0 | 2.5 | mA | |
| Supply for LCD (contrast) | VLCD | TOP = 25°C | 4.2 | 4.4 | 4.6 | 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 | - | VSS | - | 0.4 | V |
在實(shí)際應(yīng)用中,我們要確保模塊工作在這些電氣參數(shù)范圍內(nèi),否則可能會(huì)影響模塊的性能甚至導(dǎo)致?lián)p壞。
(三)光學(xué)特性
| 光學(xué)特性影響著顯示效果,包括最佳視角、對比度和響應(yīng)時(shí)間等: | Item | Symbol | Condition | Min. | Typ. | Max. | Unit | |
|---|---|---|---|---|---|---|---|---|
| Optimal Viewing Angles | Top | ?Y+ | CR ≥ 2 | - | 40 | - | ° | |
| Bottom | ?Y - | - | 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 |
工程師們在設(shè)計(jì)產(chǎn)品時(shí),要根據(jù)實(shí)際的使用場景和需求,考慮這些光學(xué)特性,以達(dá)到最佳的顯示效果。
三、指令集與初始化程序
(一)指令集
| 該模塊有一系列的指令,用于控制顯示、設(shè)置參數(shù)等。例如: | 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 |
這些指令是實(shí)現(xiàn)模塊各種功能的基礎(chǔ),我們需要熟悉它們的使用方法。
(二)初始化程序
模塊提供了8位和4位兩種初始化方式:
1. 8位初始化
void command(char i)
{
P1 = i; D1 = 0; R_W = 0; E = 1; //put data on output Port //D/I=LOW: send instruction //R/W=LOW: Write
Delay(1); //enable pulse width >= 300ns
E = 0; //Clock enable: falling edge
}
void write(char i)
{
P1 = i; DI = 1; //put data on output Port //D/=HIGH: send data
R_W = 0; E = 1; //R/W=LOW: Write
Delay(1); E = 0; //enable pulse width >= 300ns //Clock enable: falling edge
}
void init()
{
E = 0;
Delay(10); command(0x30); Delay(10); command(0x30); command(0x10); Delay(30); command(0x30); command(0x38); Delay(100); //Set cursor //command 0x30 = Wake up //command 0x30 = Wake up #3 //Nait >40 msec after power is applied //must wait 160us, busy flag not available //command 0x30 = Wake up #2 //Function set: 8 - bit/2 - line //must wait 5ms, busy flag not available //must wait 160us, busy flag not available
command(0x0c); command(0x06); //Display ON; Cursor ON //Entry mode set
}
2. 4位初始化
void command(char i)
{
P1 = i; D1 = 0; //put data on output Port //D/=LOW: send instruction
R_W = 0; Nybble(); //Send lower 4 bits //R/W=LOW: Write
i = i < 4; P1 = i; Nybble(); //Shift over by 4 bits //put data on output Port //Send upper 4 bits
}
void write(char i)
{
Nybble(); i = i < 4; DI = 1; P1 = i; R_W = 0; Nybble(); P1 = i; //put data on output Port //Clock upper 4 bits //D/l=HIGH: send data //put data on output Port //Shift over by 4 bits //Clock lower 4 bits //R/W=LOW: Write
}
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
Nybble(); P1 = 0x20; command(0x06); command(0x0F); Delay(10); command(0x10); Nybble(); command(0x28); Delay(10); Nybble(); Delay(10); //put 0x20 on the output port //can check busy flag now instead of delay //Function set: 4 - bit interface //command 0x30 = Wake up #3 //Function set: 4 - bit/2 - line //must wait 160us, busy flag not available //Set cursor //Display ON; Blinking cursor //command 0x30 = Wake up #2 //must wait 160us, busy flag not available //Entry Mode set
}
工程師們可以根據(jù)實(shí)際需求選擇合適的初始化方式,在使用過程中,要注意延時(shí)時(shí)間等參數(shù)的設(shè)置,確保初始化的正確性。
四、質(zhì)量測試
該模塊經(jīng)過了多項(xiàng)質(zhì)量測試,包括高溫存儲(chǔ)、低溫存儲(chǔ)、高溫運(yùn)行、低溫運(yùn)行、高溫高濕運(yùn)行、熱沖擊抗性、振動(dòng)測試和靜電測試等。例如高溫存儲(chǔ)測試是在+80?C下持續(xù)48小時(shí),低溫存儲(chǔ)測試是在 - 30?C下持續(xù)48小時(shí)。這些測試確保了模塊在不同環(huán)境下的可靠性和穩(wěn)定性。大家在選擇模塊時(shí),這些質(zhì)量測試數(shù)據(jù)是重要的參考依據(jù)。
總之,NHD字符液晶顯示模塊具有豐富的功能和良好的性能,電子工程師在設(shè)計(jì)相關(guān)產(chǎn)品時(shí),可以根據(jù)這些技術(shù)參數(shù)和特性,合理地進(jìn)行應(yīng)用和優(yōu)化。大家在實(shí)際使用過程中遇到過哪些問題呢?歡迎在評論區(qū)分享交流。
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NHD字符液晶顯示模塊產(chǎn)品規(guī)格解析
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