esp8266 tft lcd display price
The capability to read from an ST7789V TFT with a single bidirectional SDA pin has been added. At the moment this ONLY works with an ESP32. It is enabled with a #define TFT_SDA_READ in the setup file.
An Arduino IDE compatible graphics and fonts library for ESP8266 and ESP32 processors with drivers for ILI9341, ILI9163, ST7735, S6D02A1, ILI9481, ILI9486, ILI9488, HX8357D and ST7789 based TFT displays that support SPI. The library can be loaded using the Arduino IDE"s Library Manager.
The library supports TFT displays designed for the Raspberry Pi that are based on a ILI9486 driver chip with a 480 x 320 pixel screen. This display must be of the Waveshare design and use a 16 bit serial interface based on the 74HC04, 74HC4040 and 2 x 74HC4094 logic chips. A modification to these displays is possible (see mod image in Tools folder) to make many graphics functions much faster (e.g. 23ms to clear the screen, 1.2ms to draw a 72 pixel high numeral).
Some displays permit the internal TFT screen RAM to be read. The library supports reading from ILI9341, ST7789 and ILI9488 SPI displays for the ESP32 and ESP8266. The 8 bit parallel displays used with the ESP32 can usually can be read too. The TFT_Screen_Capture example allows full screens to be captured and sent to a PC, this is handy to create program documentation.
Support has been added recently for Waveshare 2 and 3 colour ePaper displays using full frame buffers. This addition is currently relatively immature and thus only one example has been provided. Further examples will be added soon.
The library includes a "Sprite" class, this enables flicker free updates of complex graphics. Direct writes to the TFT with graphics functions are still available, so existing sketches do not need to be changed.
A Sprite is notionally an invisible graphics screen that is kept in the processors RAM. Graphics can be drawn into the Sprite just as they can be drawn directly to the screen. Once the Sprite is completed it can be plotted onto the screen in any position. If there is sufficient RAM then the Sprite can be the same size as the screen and used as a frame buffer. Sprites by default use 16 bit colours, the bit depth can be set to 8 bits (256 colours) , or 1 bit (any 2 colours) to reduce the RAM needed. On an ESP8266 the largest 16 bit colour Sprite that can be created is about 160x128 pixels, this consumes 40Kbytes of RAM. On an ESP32 the workspace RAM is more limited than the datsheet implies so a 16 bit colour Sprite is limited to about 200x200 pixels (~80Kbytes), an 8 bit sprite to 320x240 pixels (~76kbytes). A 1 bit per pixel Sprite requires only 9600 bytes for a full 320 x 240 screen buffer, this is ideal for supporting use with 2 colour bitmap fonts.
The XPT2046 touch screen controller is supported. The SPI bus for the touch controller is shared with the TFT and only an additional chip select line is needed.
The library supports SPI overlap on the ESP8266 so the TFT screen can share MOSI, MISO and SCLK pins with the program FLASH, this frees up GPIO pins for other uses.
The library is based on the Adafruit GFX and Adafruit driver libraries and the aim is to retain compatibility. Significant additions have been made to the library to boost the speed for ESP8266/ESP32 processors (it is typically 3 to 10 times faster) and to add new features. The new graphics functions include different size proportional fonts and formatting features. There are lots of example sketches to demonstrate the different features and included functions.
Configuration of the library font selections, pins used to interface with the TFT and other features is made by editting the User_Setup.h file in the library folder, or by selecting your own configuration in the "User_Setup_Selet,h" file. Fonts and features can easily be enabled/disabled by commenting out lines.
Unfortunately the typical UNO/mcufriend TFT display board maps LCD_RD, LCD_CS and LCD_RST signals to the ESP32 analogue pins 35, 34 and 36 which are input only. To solve this I linked in the 3 spare pins IO15, IO33 and IO32 by adding wires to the bottom of the board as follows:
If the display board is fitted with a resistance based touch screen then this can be used by performing the modifications described here and the fork of the Adafruit library:
The library was intended to support only TFT displays but using a Sprite as a 1 bit per pixel screen buffer permits support for the Waveshare 2 and 3 colour SPI ePaper displays. This addition to the library is experimental and only one example is provided. Further examples will be added.
This display module features high resolution, low power consumption, wide angle and easy wiring. It employs IPS display with a small size of 1.54 inches, offering 240×240 resolution. The module adopts SPI and GDI interface(work with maincontrollers with GDI port). This LCD display can be powered by 3.3V~5V, and the maximum is power consumption is 24Ma. This product can be used in many display applications: waveform monitor display, electronic gift box, electronic weather decorations, etc.
The product is a Breakout module. It adopts SPI communication and has onboard GDI interface, which reduces the complexity of wiring and can easily display the contents read from SD card.
This is an example of commonly-used icons. 1. We use GIMP2 to convert these icons into codes for better display. 2. We provide some icons for you, Click here to find more "Click here to find more").
I don"t actually have a display at present. I purchased a 7in one some months ago. It had an LT7381 controller and was supplied with a Hunda LT7381 library for Arduino and some basic display design software. However, I couldn"t get the hardware to work despite it being described as Arduino compatible. As it turned out, it also didn"t display anything when used with the supplied USB adaptor and design software for the PC, so it may have been faulty anyway. I posted something at the time but the controller is quite new and there was not much feedback. I ended up sending it back and getting a refund although it still cost me to send it back to china.
The reason I posted was because the project is now at the stage where the LCD display really needs to be added and I intended to get advice before making another purchase. In the meantime I have been working on the project using a 20x4 display.
Thank you for that information. Since I am using an ESP8266, it sounds like I need to look for a board that uses SPI for the display. From what I can tell, it seems that some of the cheap ones from china only use SPI only for the SD card which further confuses things.
The LT7381 board referenced earlier was meant to work over SPI and that is how I tried to use it. I will make sure that whatever I get as its replacement can also be driven via SPI. I expect that the ESP8266 has insufficient pins for parallel?
I don"t posses an Arduino shield which is why I was trying to ascertain whether I need something like that. What is their purpose? A lot of photos show the display plugged into one and then into typically a Mega 2560. I don"t understand what the purpose of the shield is? Is it just a convenient way to provide a means of fitting the board to an Arduino with level shifting? SPI needs only 4 wires. Can"t these be connected directly to the ESP SPI pins?
This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on the LCD: static text, and scroll long messages. You can also use this guide with the ESP8266.
Additionally, it comes with a built-in potentiometer you can use to adjust the contrast between the background and the characters on the LCD. On a “regular” LCD you need to add a potentiometer to the circuit to adjust the contrast.
Before displaying text on the LCD, you need to find the LCD I2C address. With the LCD properly wired to the ESP32, upload the following I2C Scanner sketch.
After uploading the code, open the Serial Monitor at a baud rate of 115200. Press the ESP32 EN button. The I2C address should be displayed in the Serial Monitor.
Displaying static text on the LCD is very simple. All you have to do is select where you want the characters to be displayed on the screen, and then send the message to the display.
The next two lines set the number of columns and rows of your LCD display. If you’re using a display with another size, you should modify those variables.
Then, you need to set the display address, the number of columns and number of rows. You should use the display address you’ve found in the previous step.
To display a message on the screen, first you need to set the cursor to where you want your message to be written. The following line sets the cursor to the first column, first row.
Scrolling text on the LCD is specially useful when you want to display messages longer than 16 characters. The library comes with built-in functions that allows you to scroll text. However, many people experience problems with those functions because:
The messageToScroll variable is displayed in the second row (1 corresponds to the second row), with a delay time of 250 ms (the GIF image is speed up 1.5x).
In a 16×2 LCD there are 32 blocks where you can display characters. Each block is made out of 5×8 tiny pixels. You can display custom characters by defining the state of each tiny pixel. For that, you can create a byte variable to hold the state of each pixel.
In summary, in this tutorial we’ve shown you how to use an I2C LCD display with the ESP32/ESP8266 with Arduino IDE: how to display static text, scrolling text and custom characters. This tutorial also works with the Arduino board, you just need to change the pin assignment to use the Arduino I2C pins.