Serial LCD Module 20x4 Blue with White Backlight for Arduino

The first module I received from this vendor was DOA. Plug it in to 3v3 and nothing. Not even a back light. Completely dead. So I got an RA from Amazon and returned it for credit and at the same time I ordered another one. I needed to get product out the door. When the 2nd module came in... SAME THING. DOA *again*!!!Understand that I have two of these exact same displays from other vendors and they work fine. Same wiring harness, same CPU. Same commodity product. They even have the same PCB identifiers and markings. So the ONLY difference is the reseller. I literally can plug a good one in, boot my product (an in-production serial MMI Interface for CNC) and it works. Swap the display with one from this seller and NADA.These things are just junk. After two attempts, I’ll switch vendors. Beware. YMMV.

Per comments above, they talk about J1 and J2 - Mine does not have a separate J1 or J2 - it simply has a strip of 10 continuous holes. There is a sticker which says this is an NKC2004SD-SSW-BBW. Perhaps this is the wrong unit?

Really nice. Documentation and sample code available was terrible, but eventually pieced it together. Hope the Arduino sample code below helps you all out:/* NKC Electronics 20x4 Serial LCD test 20x4 Serial LCD pinout for UART serial communicationpin 1: RXpin 2: GNDpin 3: +5Vconnect pin1 to Arduino digital pin 4connect pin2 to Arduino GNDconnect pin3 to Arduino +5VMore info:[...] */#include <SoftwareSerial.h>// since the LCD does not send data back to the Arduino, we should only define the txPi#define txPin 4 // White wire from Serial LCD screenconst int LCDdelay = 10; // conservative, 2 actually worksSoftwareSerial LCD(0, txPin);void lcdPosition(int row, int col) { LCD.write(0xFE); //command flag LCD.write((col + row*64 + 128)); //position delay(LCDdelay);}/*void lcdPositionLine1() { LCD.write(0xFE); //command flag LCD.write(0x45); LCD.write(0x00); delay(LCDdelay);}*/void lcdPositionLine2() { LCD.write(0xFE); //command flag LCD.write(0x45); LCD.write(0x40); delay(LCDdelay);}void lcdPositionLine3() { LCD.write(0xFE); //command flag LCD.write(0x45); LCD.write(0x14); delay(LCDdelay);}void lcdPositionLine4() { LCD.write(0xFE); //command flag LCD.write(0x45); LCD.write(0x54); delay(LCDdelay);}void clearLCD(){ LCD.write(0xFE); //command flag LCD.write(0x51); //clear command. delay(LCDdelay);}void serCommand(){ //a general function to call the command flag for issuing all other commands LCD.write(0xFE);}void setLCDContrast() { LCD.write(0xFE); //command flag LCD.write(0x52); LCD.write(40); //value 1 to 50 (50 is highest contrast) delay(LCDdelay);}void setLCDBrightness() { LCD.write(0xFE); //command flag LCD.write(0x53); LCD.write(5); //value 1 to 8 delay(LCDdelay);}void setup(){ Serial.begin(57600); pinMode(txPin, OUTPUT); LCD.begin(9600); //lcdPosition(0,0); clearLCD(); setLCDContrast(); setLCDBrightness(); LCD.print("Hello line 1"); lcdPositionLine2(); LCD.print("W33333333333333rrrrrrrrrrrrdddddddd"); lcdPositionLine3(); LCD.print("Pop it like its hot");}void loop(){}

This character LCD is a nice display for what you pay, just keep in mind you are ordering a component and not a finished retail product. As the other reviewer mentioned, if you have worked with serial LCD's or even parallel LCD's you can have this one running in minutes. While it has a slightly different command set than the Sparkfun serial LCD's, these use the same command set as New Haven Displays, of which there are many classes out there for the various micro controllers.The nice thing about this particular LCD is that while it comes as a serial driven display, on the back of the board there are two jumper pads you can solder to set the display to use either I2C or SPI. I uploaded an image to the gallery which notes the area of the jumpers. Having this flexibility built in (with no daughter boards nonetheless) makes this LCD suited for many projects.I have one gripe with the display and that is when a character is blinking, the character directly below it also blinks with it a bit. Other than that I have been pleasantly surprised with just how fast it draws full text, even with the default baud rate of 9600bps.

So, this ships with the display in an anti-static bag. That's it.There are no jumpers, pins, cables, or documentation. The board is unlabeled. There are limited docs (follow the links in the description) that refer to pins. But they're not labeled.There's example code, but it's for a 16x2 LCD.Sadly, despite the quality seeming high - this one is going back. Don't do it :)

Works fine.

Dead easy to use. It took me maybe 3 minutes to get it talking to a Bus Pirate (And most of that was having to look up the bus-pirate pinout. I can never remember it).The datasheet has everything you need. The guy who is complaining about the documentation must not have any idea what he's doing. If you think the datasheet for this LCD is sparse, you haven't read many datasheets.Note that this is not for the inexperienced. This isn't really for the arduino crowd, unless you know what you're doing. If you don't know what HD44780 means, you should go look at buying something targeted more at a beginner. The docs have the pinout, and describe the command interface, but you actually need to know how to implement it. If you expect a PCB with labeling on the pins, well, welcome to the real world.On the other hand, if you know off-hand what 9600N1 means, and that the square pad is pin 1, you shouldn't have any issues.

This is a great LCD module that is extremely easy to program and use and looks great. There are many other LCD modules on the market, some of them even cheaper than this one. However, I think the best thing about this module is the seller...NKC. Service is unmatched! I have several of these modules and had trouble with a couple of them and NKC replaced them very quickly and with no fuss. I'll be buying more!