nodemcu lcd display brands

In IoT, LCD is rarely required, but some times its useful to monitor errors and connection related issues. In this tutorial we are interfacingI2C LCD with ESP8266 or ESP32.Both code examples are given.

This library is tested for different types of LCD displays like 16×2, 16×4, 20×2, 20×4 with both ESP32 and ESP8266, it also works with other ESP modules.

ESP8266 with 20×4 i2c, 1602 LCD adaptable to others, tested with ESP-201 and ESP-01 Compatible with the Arduino IDE 1.6.6 Library https://github.com/agnunez/ESP8266-I2C-LCD1602

This is simple code to display text, cursor and scrolling text. Upload this code it will demonstrate many functions of library such as scrolling, display on off, cursor positioning

Want to display sensor readings in your ESP8266 projects without resorting to serial output? Then an I2C LCD display might be a better choice for you! It consumes only two GPIO pins which can also be shared with other I2C devices.

True to their name, these LCDs are ideal for displaying only text/characters. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows of 16 characters each.

If you look closely you can see tiny rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.

At the heart of the adapter is an 8-bit I/O expander chip – PCF8574. This chip converts the I2C data from an ESP8266 into the parallel data required for an LCD display.

If you are using multiple devices on the same I2C bus, you may need to set a different I2C address for the LCD adapter so that it does not conflict with another I2C device.

An important point here is that several companies manufacture the same PCF8574 chip, Texas Instruments and NXP Semiconductors, to name a few. And the I2C address of your LCD depends on the chip manufacturer.

So your LCD probably has a default I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it.

Connecting I2C LCD to ESP8266 is very easy as you only need to connect 4 pins. Start by connecting the VCC pin to the VIN on the ESP8266 and GND to ground.

After wiring up the LCD you’ll need to adjust the contrast of the display. On the I2C module you will find a potentiometer that you can rotate with a small screwdriver.

Plug in the ESP8266’s USB connector to power the LCD. You will see the backlight lit up. Now as you turn the knob on the potentiometer, you will start to see the first row of rectangles. If that happens, Congratulations! Your LCD is working fine.

The I2C address of your LCD depends on the manufacturer, as mentioned earlier. If your LCD has a Texas Instruments’ PCF8574 chip, its default I2C address is 0x27Hex. If your LCD has NXP Semiconductors’ PCF8574 chip, its default I2C address is 0x3FHex.

So your LCD probably has I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it. Luckily there’s an easy way to do this. Below is a simple I2C scanner sketch that scans your I2C bus and returns the address of each I2C device it finds.

After uploading the code, open the serial monitor at a baud rate of 115200 and press the EN button on the ESP8266. You will see the I2C address of your I2C LCD display.

But, before you proceed to upload the sketch, you need to make a small change to make it work for you. You must pass the I2C address of your LCD and the dimensions of the display to the constructor of the LiquidCrystal_I2C class. If you are using a 16×2 character LCD, pass the 16 and 2; If you’re using a 20×4 LCD, pass 20 and 4. You got the point!

First of all an object of LiquidCrystal_I2C class is created. This object takes three parameters LiquidCrystal_I2C(address, columns, rows). This is where you need to enter the address you found earlier, and the dimensions of the display.

In ‘setup’ we call three functions. The first function is init(). It initializes the LCD object. The second function is clear(). This clears the LCD screen and moves the cursor to the top left corner. And third, the backlight() function turns on the LCD backlight.

After that we set the cursor position to the third column of the first row by calling the function lcd.setCursor(2, 0). The cursor position specifies the location where you want the new text to be displayed on the LCD. The upper left corner is assumed to be col=0, row=0.

lcd.scrollDisplayRight() function scrolls the contents of the display one space to the right. If you want the text to scroll continuously, you have to use this function inside a for loop.

lcd.scrollDisplayLeft() function scrolls the contents of the display one space to the left. Similar to above function, use this inside a for loop for continuous scrolling.

If you find the characters on the display dull and boring, you can create your own custom characters (glyphs) and symbols for your LCD. They are extremely useful when you want to display a character that is not part of the standard ASCII character set.

CGROM is used to store all permanent fonts that are displayed using their ASCII codes. For example, if we send 0x41 to the LCD, the letter ‘A’ will be printed on the display.

CGRAM is another memory used to store user defined characters. This RAM is limited to 64 bytes. For a 5×8 pixel based LCD, only 8 user-defined characters can be stored in CGRAM. And for 5×10 pixel based LCD only 4 user-defined characters can be stored.

After the library is included and the LCD object is created, custom character arrays are defined. The array consists of 8 bytes, each byte representing a row of a 5×8 LED matrix. In this sketch, eight custom characters have been created.

NodeMCU has ESP-12 based serial WiFi integrated on board to provide GPIO, PWM, ADC, I2C and 1-WIRE resources at your finger tips, built-in USB-TTL serial with super reliable industrial strength CH340 for superior stability on all supported platforms.

The breakout has the TFT display soldered on (it uses a delicate flex-circuit connector) as well as a ultra-low-dropout 3.3V regulator and a 3/5V level shifter so that you can use it with 3.3V or 5V power and TTL control logic.

It will scan and display all nearby networks found. An important note, our display has only three lines, so we have to work with logic to display only 3 networks at a time. Because of this, we use an auxiliary array that will receive 3 networks to be displayed.

As our display only works with 3 networks, we have to go through the array and break it into 3 parts at a time, for that when the cursor is a value multiple of 3 the display is updated with the next 3 networks and so on.

This method will connect the ESP to the desired network. On the first click, the network where the course points will be selected and the display will show the name and request the password to access the network. For this project I didn"t have an external keyboard to enter the password, so I had to enter the hard code password.

I think the Wire.begin() syntax is Wire.begin(SDA, SCL);. So, for the code to match the diagram it would be Wire.begin(4,3);. I also connected my display"s LCD Vcc to Vin on the NodeMCU which differs from the diagram. It works for me with these changes.

Wire.begin(2.0) is same with Wire.begin(D4,D3), the different is (2.0) is GPIO pin, only name is different but is referring to the same pin, u can google the pin out of nodeMCU.

i know it"s late but..i"ve found some solution for this problem..at least it was for me..try change "lcd.backlight();" to "lcd.setBacklight((uint8_t)1);0

he copiado el programa en un nodemcu v3 de lolin en el IDE y cuando lo clequeo me aparece el siguiente error: Tampoco me funciona lo de dar corriente a traves del pin Vin a la lcd, le proporciono corriente a traves de un pin 3,3V