Weewooday 4set Iic TWI I2c LCD Serial Interface Adapter and Liquid Crystal Display Module Display Backlight Compatible with Arduino R3 Mega2560(LCD 1602 16 x 2,Blue)

All four LCD displays worked. No issues. I use them for miniture remote weather stations. Instructions are clear enough and sketches are available, but not from me.

four out of four work as expected.I am very please with the purchase.Will definitely buy again.

I wish I could give more than 5 stars on “value for money” I never realized how much cheaper it is if you spend an extra 5 minutes to solder the board yourself! You don’t have to be an expert to solder it either, it’s very simple, very basic, quick, and easy! The screens work great, once dialed in with the small screw on the back, they work great and are very responsive to changes.

good price

Like it. It's working like should.

The boards seem to work but with some errors even after downloading the libraries<LiquidCrystal_I2C.h><Wire.h><hd44780.h><hd44780ioClass/hd44780_I2Cexp.h>I can print Hello World! but trying anything else is giving me multiple problems and wrong characters. so far I have soldered two of the HD44780 to the 1602A boards, tested them by trying them with an ESP8266 12-E boards multiple ways, de soldered them and re-soldered them and then ohms metered them to ensure connections, Should've just ohms first my solders looked good but i was going from the readout of the I2Cexpdiag and pulling my hair out...I2Cexpdiag Monitor Output> ********************************************************************> Serial Initialized> --------------------------------------------------------------------> I2CexpDiag - i2c LCD i/o expander backpack diagnostic tool> --------------------------------------------------------------------> hd44780 lib version: 1.3.2> --------------------------------------------------------------------> Reported Arduino Revision: 1.8.14> Arduino Board: ESP8266_NODEMCU_ESP12E> CPU ARCH: ESP8266 - F_CPU: 80000000> --------------------------------------------------------------------> SDA digital pin: 4 (GPIO4)> SCL digital pin: 5 (GPIO5)> --------------------------------------------------------------------> Checking for required external I2C pull-up on SDA - YES> Checking for required external I2C pull-up on SCL - YES> Checking for I2C pins shorted together - Not Shorted> --------------------------------------------------------------------> Scanning i2c bus for devices..> i2c device found at address 0x27> Total I2C devices found: 1> --------------------------------------------------------------------> Scanning i2c bus for all lcd displays (4 max)> LCD at address: 0x27 | config: P01245673H | R/W control: Yes> Total LCD devices found: 1> --------------------------------------------------------------------> LCD Display Memory Test> Display: 0> Walking 1s data test: Read Error after writing 10> Compare error: addr: 40 read 2 != wrote 20> Compare error: addr: 40 read 2 != wrote 40> Compare error: addr: 40 read 2 != wrote 80>> Compare error: addr: 10 read 2 != wrote 1> Compare error: addr: 10 read 2 != wrote 4> Compare error: addr: 10 read 2 != wrote 8> Compare error: addr: 10 read 2 != wrote 10> Compare error: addr: 10 read 2 != wrote 20> Compare error: addr: 10 read 2 != wrote 40> Compare error: addr: 10 read 2 != wrote 80>> Compare error: addr: 50 read 2 != wrote 1> Compare error: addr: 50 read 8 != wrote 4> Compare error: addr: 50 read 2 != wrote 8> Compare error: addr: 50 read 2 != wrote 10> Compare error: addr: 50 read 2 != wrote 20> Compare error: addr: 50 read 2 != wrote 40> Compare error: addr: 50 read 2 != wrote 80> FAILED> Address line test:> Read Error addr: 19> Compare error: addr: 0 read 8 != wrote 0> Compare error: addr: 1 read 8 != wrote 1> Compare error: addr: 2 read F != wrote 2> Compare error: addr: 3 read 22 != wrote 3> Compare error: addr: 4 read 2 != wrote 4> Compare error: addr: 5 read 20 != wrote 5> Compare error: addr: 6 read 4 != wrote 6> Compare error: addr: 7 read 20 != wrote 7> Compare error: addr: 9 read 20 != wrote 9> Compare error: addr: B read 0 != wrote B> Compare error: addr: C read 10 != wrote C> Compare error: addr: E read 20 != wrote E> Compare error: addr: 10 read 8F != wrote 10> Compare error: addr: 11 read 20 != wrote 11> Compare error: addr: 12 read 20 != wrote 12> Read Error addr: 18> Compare error: addr: 19 read 91 != wrote 19> Compare error: addr: 1A read 20 != wrote 1A> Compare error: addr: 1B read 20 != wrote 1B> Compare error: addr: 1C read 20 != wrote 1C> Compare error: addr: 1D read 20 != wrote 1D> Compare error: addr: 1E read 20 != wrote 1E> Compare error: addr: 1F read 12 != wrote 1F> Compare error: addr: 20 read 1F != wrote 20> Compare error: addr: 21 read 20 != wrote 21> Compare error: addr: 22 read 20 != wrote 22> Compare error: addr: 23 read 20 != wrote 23> Compare error: addr: 24 read 20 != wrote 24> Compare error: addr: 25 read 20 != wrote 25> Compare error: addr: 26 read 20 != wrote 26> Compare error: addr: 27 read 20 != wrote 27>> Compare error: addr: 40 read 45 != wrote 40> Compare error: addr: 41 read 45 != wrote 41> Compare error: addr: 42 read 4F != wrote 42> Compare error: addr: 5F read F6 != wrote 5F> Compare error: addr: 60 read E5 != wrote 60> Compare error: addr: 61 read F6 != wrote 61> Read Error addr: 62> Compare error: addr: 63 read 60 != wrote 63> FAILED> Memory test failures are usually due to poor solder connections> Most common cause is poor solder joints on pins soldered to the LCD>> --------------------------------------------------------------------> No working LCD devices

Everything worked fine. The I2C controller is much more convenient then trying to directly wire into all of the pins. I've only needed to use 1 so far, so 3 extra are nice.

Great price, all woff egg led for me. For some reason contrast was turned all the way down on all of them. Once adjusted worked fine.

Fonctionne extremement bien

Only i2c had been receved!where are displayed 1602 Module

Muy buen producto llego bien empaquetado, ademas que es una buena opción para reducir cableado al enlazarlo con un microcontrolador.

I purchased four units and they all worked fine.If the screen appears blank when you connect.... try rotating the potentiometer at the rear. DON'T FORCE IT.Remember, their hexadecimal addresses may not be set to your default address. My addresses all required changing. Changing the address is quite easy. If you do not understand these instructions, there are some interesting YouTube tutorials. 1. Connect the I2C board to 5v VCC and also to ground. 2. Connect the SDA of the I2C board to the SDA of your Arduino 3. Connect the SCL of the I2C board to the SCL of your Arduino 4. Copy this sketch to the Arduino IDE then upload it to your Arduino 5. Open the IDE Serial Monitor and you should be able to see a list of the used addresses 6. Your LCD1602 will be listed here 7. Once you find the the number, change your Sketch 8. Example...... LiquidCrystal_I2C lcd(0x27, 16, 2); 9. If you can't count in hexadecimal, Google can help10. It's the 0x27 number which will require changing// I2CScanner.ino -- I2C bus scanner for Arduino#include "Wire.h"extern "C" {#include "utility/twi.h" // from Wire library, so we can do bus scanning}// Scan the I2C bus between addresses from_addr and to_addr.// On each address, call the callback function with the address and result.// If result==0, address was found, otherwise, address wasn't found// (can use result to potentially get other status on the I2C bus, see twi.c)// Assumes Wire.begin() has already been calledvoid scanI2CBus(byte from_addr, byte to_addr, void(*callback)(byte address, byte result) ){ byte rc; byte data = 0; // not used, just an address to feed to twi_writeTo() for( byte addr = from_addr; addr <= to_addr; addr++ ) { rc = twi_writeTo(addr, &data, 0, 1, 0); callback( addr, rc ); }}// Called when address is found in scanI2CBus()// Feel free to change this as needed// (like adding I2C comm code to figure out what kind of I2C device is there)void scanFunc( byte addr, byte result ) { Serial.print("addr: "); Serial.print(addr,DEC); Serial.print( (result==0) ? " found!":" "); Serial.print( (addr%4) ? "\t":"\n");}byte start_address = 8; // lower addresses are reserved to prevent conflicts with other protocolsbyte end_address = 119; // higher addresses unlock other modes, like 10-bit addressing// standard Arduino setup()void setup(){ Wire.begin(); Serial.begin(9600); // Changed from 19200 to 9600 which seems to be default for Arduino serial monitor Serial.println("\nI2CScanner ready!"); Serial.print("starting scanning of I2C bus from "); Serial.print(start_address,DEC); Serial.print(" to "); Serial.print(end_address,DEC); Serial.println("..."); // start the scan, will call "scanFunc()" on result from each address scanI2CBus( start_address, end_address, scanFunc ); Serial.println("\ndone"); // Set pin mode so the loop code works ( Not required for the functionality) pinMode(13, OUTPUT);}// standard Arduino loop()void loop(){ // Nothing to do here, so we'll just blink the built-in LED digitalWrite(13,HIGH); delay(300); digitalWrite(13,LOW); delay(300);}

Excellent as described