tft lcd 2 nodemcu arduino code for sale

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Needs some wiring. This shield can"t be used directly on Wemos D1, because two pins are duplicated to the Arduino connectors: D5 is SCK and digital 5, D6 is MISO and digital 6.

ILI9341 is a 262,144-color single-chip SOC driver for a-TFT liquid crystal display with resolution of 240RGBx320 dots, comprising a 720-channel source driver, a 320-channel gate driver, 172,800 bytes GRAM for graphic display data of 240RGBx320 dots, and power supply circuit. ILI9341 supports parallel 8-/9-/16-/18-bit data bus MCU interface, 6-/16-/18-bit data bus RGB interface and 3-/4-line serial peripheral interface (SPI). The moving picture area can be specified in internal GRAM by window address function. The specified window area can be updated selectively, so that moving picture can be displayed simultaneously independent of still picture area.

You can find ILI9341-based TFT displays in various sizes on eBay and Aliexpress. The one I chose for this tutorial is 2.2″ length along the diagonal, 240×320 pixels resolution, supports SPI interface, and can be purchased for less than $10.

Note that we will be using the hardware SPI module of the ESP8266 to drive the TFT LCD. The SPI communication pins are multiplexed with I/O pins D5 (SCK), D6 (MISO), and D7 (MOSI). The chip select (CS) and Data/Command (DC) signal lines are configurable through software.

For ILI9341-based TFT displays, there are some options for choosing the library for your application. The most common one is using Bodmer. We will use this library in this tutorial. So go ahead and download the

The library contains proportional fonts, different sizes can be enabled/disabled at compile time to optimise the use of FLASH memory. The library has been tested with the NodeMCU (ESP8266 based).

The library is based on the Adafruit GFX and Adafruit ILI9341 libraries and the aim is to retain compatibility. Significant additions have been made to the library to boost the speed for ESP8266 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 a significant number of example sketches to demonstrate the different features.

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. Fonts and features can easily be disabled by commenting out lines.

Now you are all set to try out tons of really cool built-in examples that come with the library. The following output corresponds to the TFT_Pie_Chart example.

My favorite example is TFT terminal, which implements a simple “Arduino IDE Serial Monitor” like serial receive terminal for monitoring debugging messages from another Arduino or ESP8266 board.

Hi, in this tutorial we will see how to control electrical devices like fan, light, etc., to turn on and off using esp8266 from a web browser. if you are bored with a dedicated device controller like an app or an remote which will be available for only one particular device but using this method all the device which support web browsing will be act as a controller for us.

Components that you need for completing this project are very simple, you need to have an esp8266 wifi module and a relay, make sure you buying a 5v relay which very easy to use with esp chips doesn"t require external supply too. we can make use of the Vin pin of the nodemcu or if you are using a generic chip, you need to supply an external 5v to the relay.

Copy the below arduino code and paste into your Arduino IDE and upload the program to your nodemcu or any other esp devices that you are using, make sure to choose the correct port and device name from the board. also don"t forget to change the SSID and password to your Wi-fi settings.

This program for the esp8266 wrote to return the status of the device , which will in turn notify us with the device state in the browser which will also make the user to know which device has currently turned on or off.

if you like the above tutorial and if you want try out with cool projects you can also check this link here , that"s the amazon book link where you can use that book to make IoT with Esp8266 or Nodemcu, that books gives you basic coverage on how to do simple things and get yourself started with arduino and goes on developing projects like sending data to webserver and creating a webserver, uploading and controlling data from a webpage, how to interface TFT LCD and I2C devices and many more things can find on the link.

The ESP8266 is a well performing microcontroller chip that is fully Arduino compatible. Its WiFi capability makes boards with this chip easy implementable as IOT devices. Here we wire two representative ESP8266 boards: NodeMCU and Wemos D1 mini to a single-row 14-pin header, 320*240 TFT display that uses the four-wire SPI interface.

Here we connect a 320240 ILI9341 TFT display that has a SPI pin-out. This breakout board has 3.3V controller logic while power supply and background illumination operate on either 3.3V and 5V. ESP8266 microcontroller boards support displays with up to 320480 pixels

The display shown in figure 1 has a touch screen. It has a single row of 14 pins (figure 1; see also figure 3). The pins supporting ‘touch’ as well as those associated with the SD card reader are not connected: we concentrate on displaying text, variables, graphics and fast sequences of memory-loaded bitmaps (‘image frames”). The ILI9341 controller is fast and, in combination with an ESP8266, performs excellently.

Figure 3 shows a Wemos D1 mini board mounted on a prototyping breadboard together with a 2.8 inch ILI9341 SPI TFT display according to the wiring diagram shown in Figure 2. The ESP8266 is running a demo adapted for the “Adafruit_GFX.h” and “Adafruit_ILI9341.h” libraries from Bodmer’s ‘Clock’ example for his TFT_eSPI library.

— ESP8266_ILI9341_Adafruit_Bodmers_clock.ino, a real time analog clock example adapted from Bodmer’s TFT_eSPi library examples (display visible in figure 3).

In this guide we’re going to show you how you can use the 1.8 TFT display with the Arduino. You’ll learn how to wire the display, write text, draw shapes and display images on the screen.

The 1.8 TFT is a colorful display with 128 x 160 color pixels. The display can load images from an SD card – it has an SD card slot at the back. The following figure shows the screen front and back view.

This module uses SPI communication – see the wiring below . To control the display we’ll use the TFT library, which is already included with Arduino IDE 1.0.5 and later.

The TFT display communicates with the Arduino via SPI communication, so you need to include the SPI library on your code. We also use the TFT library to write and draw on the display.

The 1.8 TFT display can load images from the SD card. To read from the SD card you use the SD library, already included in the Arduino IDE software. Follow the next steps to display an image on the display:

In this guide we’ve shown you how to use the 1.8 TFT display with the Arduino: display text, draw shapes and display images. You can easily add a nice visual interface to your projects using this display.

The ESP8266 is a well performing microcontroller chip that is fully Arduino compatible. Its WiFi capability makes boards with this chip easy implementable as IOT devices. Here we wire two representative ESP8266 boards: NodeMCU and Wemos D1 mini to a single-row 14-pin header, 320*240 TFT display that uses the four-wire SPI interface.

Here we connect a 320240 ILI9341 TFT display that has a SPI pin-out. This breakout board has 3.3V controller logic while power supply and background illumination operate on either 3.3V and 5V. ESP8266 microcontroller boards support displays with up to 320480 pixels

The display shown in figure 1 has a touch screen. It has a single row of 14 pins (figure 1; see also figure 3). The pins supporting ‘touch’ as well as those associated with the SD card reader are not connected: we concentrate on displaying text, variables, graphics and fast sequences of memory-loaded bitmaps (‘image frames”). The ILI9341 controller is fast and, in combination with an ESP8266, performs excellently.

Figure 3 shows a Wemos D1 mini board mounted on a prototyping breadboard together with a 2.8 inch ILI9341 SPI TFT display according to the wiring diagram shown in Figure 2. The ESP8266 is running a demo adapted for the “Adafruit_GFX.h” and “Adafruit_ILI9341.h” libraries from Bodmer’s ‘Clock’ example for his TFT_eSPI library.

— ESP8266_ILI9341_Adafruit_Bodmers_clock.ino, a real time analog clock example adapted from Bodmer’s TFT_eSPi library examples (display visible in figure 3).

In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.

The next example is controlling an RGB LED using these three RGB sliders. For example if we start to slide the blue slider, the LED will light up in blue and increase the light as we would go to the maximum value. So the sliders can move from 0 to 255 and with their combination we can set any color to the RGB LED,  but just keep in mind that the LED cannot represent the colors that much accurate.

As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.

Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.

As the code is a bit longer and for better understanding I will post the source code of the program in sections with description for each section. And at the end of this article I will post the complete source code.

I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.

After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.

So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels  down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.

Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.

In order the code to work and compile you will have to include an addition “.c” file in the same directory with the Arduino sketch. This file is for the third game example and it’s a bitmap of the bird. For more details how this part of the code work  you can check my particular tutorial. Here you can download that file:

An excellent new compatible library is available which can render TrueType fonts on a TFT screen (or into a sprite). This has been developed by takkaO and is available here. I have been reluctant to support yet another font format but this is an amazing library which is very easy to use. It provides access to compact font files, with fully scaleable anti-aliased glyphs. Left, middle and right justified text can also be printed to the screen. I have added TFT_eSPI specific examples to the OpenFontRender library and tested on RP2040 and ESP32 processors, however the ESP8266 does not have sufficient RAM. Here is a demo screen where a single 12kbyte font file binary was used to render fully anti-aliased glyphs of gradually increasing size on a 320x480 TFT screen:

For ESP32 ONLY, the TFT configuration (user setup) can now be included inside an Arduino IDE sketch providing the instructions in the example Generic->Sketch_with_tft_setup are followed. See ReadMe tab in that sketch for the instructions. If the setup is not in the sketch then the library settings will be used. This means that "per project" configurations are possible without modifying the library setup files. Please note that ALL the other examples in the library will use the library settings unless they are adapted and the "tft_setup.h" header file included. Note: there are issues with this approach, #2007 proposes an alternative method.

Support has been added in v2.4.70 for the RP2040 with 16 bit parallel displays. This has been tested and the screen update performance is very good (4ms to clear 320 x 480 screen with HC8357C). The use of the RP2040 PIO makes it easy to change the write cycle timing for different displays. DMA with 16 bit transfers is also supported.

Support for the ESP32-S2, ESP32-S3 and ESP32-C3 has been added (DMA not supported at the moment). Tested with v2.0.3 RC1 of the ESP32 board package. Example setups:

Smooth fonts can now be rendered direct to the TFT with very little flicker for quickly changing values. This is achieved by a line-by-line and block-by-block update of the glyph area without drawing pixels twice. This is a "breaking" change for some sketches because a new true/false parameter is needed to render the background. The default is false if the parameter is missing, Examples:

Frank Boesing has created an extension library for TFT_eSPI that allows a large range of ready-built fonts to be used. Frank"s library (adapted to permit rendering in sprites as well as TFT) can be downloaded here. More than 3300 additional Fonts are available here. The TFT_eSPI_ext library contains examples that demonstrate the use of the fonts.

Users of PowerPoint experienced with running macros may be interested in the pptm sketch generator here, this converts graphics and tables drawn in PowerPoint slides into an Arduino sketch that renders the graphics on a 480x320 TFT. This is based on VB macros created by Kris Kasprzak here.

The RP2040 8 bit parallel interface uses the PIO. The PIO now manages the "setWindow" and "block fill" actions, releasing the processor for other tasks when areas of the screen are being filled with a colour. The PIO can optionally be used for SPI interface displays if #define RP2040_PIO_SPI is put in the setup file. Touch screens and pixel read operations are not supported when the PIO interface is used.

The use of PIO for SPI allows the RP2040 to be over-clocked (up to 250MHz works on my boards) in Earle"s board package whilst still maintaining high SPI clock rates.

DMA can now be used with the Raspberry Pi Pico (RP2040) when used with both 8 bit parallel and 16 bit colour SPI displays. See "Bouncy_Circles" sketch.

The library now supports the Raspberry Pi Pico with both the official Arduino board package and the one provided by Earle Philhower. The setup file "Setup60_RP2040_ILI9341.h" has been used for tests with an ILI9341 display. At the moment only SPI interface displays have been tested. SPI port 0 is the default but SPI port 1 can be specifed in the setup file if those SPI pins are used.

The library now provides a "viewport" capability. See "Viewport_Demo" and "Viewport_graphicstest" examples. When a viewport is defined graphics will only appear within that window. The coordinate datum by default moves to the top left corner of the viewport, but can optionally remain at top left corner of TFT. The GUIslice library will make use of this feature to speed up the rendering of GUI objects (see #769).

An Arduino IDE compatible graphics and fonts library for 32 bit processors. The library is targeted at 32 bit processors, it has been performance optimised for RP2040, STM32, ESP8266 and ESP32 types, other processors may be used but will use the slower generic Arduino interface calls. The library can be loaded using the Arduino IDE"s Library Manager. Direct Memory Access (DMA) can be used with the ESP32, RP2040 and STM32 processors with SPI interface displays to improve rendering performance. DMA with a parallel interface (8 and 16 bit parallel) is only supported with the RP2040.

For other processors only SPI interface displays are supported and the slower Arduino SPI library functions are used by the library. Higher clock speed processors such as used for the Teensy 3.x and 4.x boards will still provide a very good performance with the generic Arduino SPI functions.

"Four wire" SPI and 8 bit parallel interfaces are supported. Due to lack of GPIO pins the 8 bit parallel interface is NOT supported on the ESP8266. 8 bit parallel interface TFTs (e.g. UNO format mcufriend shields) can used with the STM32 Nucleo 64/144 range or the UNO format ESP32 (see below for ESP32).

The library supports some TFT displays designed for the Raspberry Pi (RPi) that are based on a ILI9486 or ST7796 driver chip with a 480 x 320 pixel screen. The ILI9486 RPi 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. Note that due to design variations between these displays not all RPi displays will work with this library, so purchasing a RPi display of these types solely for use with this library is NOT recommended.

A "good" RPi display is the MHS-4.0 inch Display-B type ST7796 which provides good performance. This has a dedicated controller and can be clocked at up to 80MHz with the ESP32 (125MHz with overclocked RP2040, 55MHz with STM32 and 40MHz with ESP8266). The MHS-3.5 inch RPi ILI9486 based display is also supported, however the MHS ILI9341 based display of the same type does NOT work with this library.

Some displays permit the internal TFT screen RAM to be read, a few of the examples use this feature. The TFT_Screen_Capture example allows full screens to be captured and sent to a PC, this is handy to create program documentation.

The library supports Waveshare 2 and 3 colour ePaper displays using full frame buffers. This addition is relatively immature and thus only one example has been provided.

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 datasheet 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.

One or more sprites can be created, a sprite can be any pixel width and height, limited only by available RAM. The RAM needed for a 16 bit colour depth Sprite is (2 x width x height) bytes, for a Sprite with 8 bit colour depth the RAM needed is (width x height) bytes. Sprites can be created and deleted dynamically as needed in the sketch, this means RAM can be freed up after the Sprite has been plotted on the screen, more RAM intensive WiFi based code can then be run and normal graphics operations still work.

Drawing graphics into a sprite is very fast, for those familiar with the Adafruit "graphicstest" example, this whole test completes in 18ms in a 160x128 sprite. Examples of sprite use can be found in the "examples/Sprite" folder.

If an ESP32 board has SPIRAM (i.e. PSRAM) fitted then Sprites will use the PSRAM memory and large full screen buffer Sprites can be created. Full screen Sprites take longer to render (~45ms for a 320 x 240 16 bit Sprite), so bear that in mind.

The "Animated_dial" example shows how dials can be created using a rotated Sprite for the needle. To run this example the TFT interface must support reading from the screen RAM (not all do). The dial rim and scale is a jpeg image, created using a paint program.

The XPT2046 touch screen controller is supported for SPI based displays only. The SPI bus for the touch controller is shared with the TFT and only an additional chip select line is needed. This support will eventually be deprecated when a suitable touch screen library is available.

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. Only one SPI device can be connected to the FLASH pins and the chips select for the TFT must be on pin D3 (GPIO0).

The library contains proportional fonts, different sizes can be enabled/disabled at compile time to optimise the use of FLASH memory. Anti-aliased (smooth) font files in vlw format stored in SPIFFS are supported. Any 16 bit Unicode character can be included and rendered, this means many language specific characters can be rendered to the screen.

Configuration of the library font selections, pins used to interface with the TFT and other features is made by editing 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.

Anti-aliased (smooth) font files in "vlw" format are generated by the free Processing IDE using a sketch included in the library Tools folder. This sketch with the Processing IDE can be used to generate font files from your computer"s font set or any TrueType (.ttf) font, the font file can include any combination of 16 bit Unicode characters. This means Greek, Japanese and any other UCS-2 glyphs can be used. Character arrays and Strings in UTF-8 format are supported.

The .vlw files must be uploaded to the processors FLASH filing system (SPIFFS, LittleFS or SD card) for use. Alternatively the .vlw files can be converted to C arrays (see "Smooth Font -> FLASH_Array" examples) and stored directly in FLASH as part of the compile process. The array based approach is convenient, provides performance improvements and is suitable where: either use of a filing system is undesirable, or the processor type (e.g. STM32) does not support a FLASH based filing system.

It would be possible to compress the vlw font files but the rendering performance to a TFT is still good when storing the font file(s) in SPIFFS, LittleFS or FLASH arrays.

Anti-aliased fonts can also be drawn over a gradient background with a callback to fetch the background colour of each pixel. This pixel colour can be set by the gradient algorithm or by reading back the TFT screen memory (if reading the display is supported).

The common 8 bit "Mcufriend" shields are supported for the STM Nucleo 64/144 boards and ESP32 UNO style board. The STM32 "Blue/Black Pill" boards can also be used with 8 bit parallel displays.

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 you load a new copy of TFT_eSPI then it will overwrite your setups if they are kept within the TFT_eSPI folder. One way around this is to create a new folder in your Arduino library folder called "TFT_eSPI_Setups". You then place your custom setup.h files in there. After an upgrade simply edit the User_Setup_Select.h file to point to your custom setup file e.g.:

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.

Want to add little graphic pizzazz to your ESP8266 IoT projects? Or maybe you want to display IP address of your ESP8266 without resorting to serial output. These super-cool OLED (Organic Light-Emitting Diode) displays might be the perfect fit! They’re super-light, almost paper-thin, theoretically flexible, and produce a brighter and crisper picture.

The OLED display module breaks out a small monochrome OLED display. It’s 128 pixels wide and 64 pixels tall, measuring 0.96″ across. It’s micro, but it still packs a punch – the OLED display is very readable due to the high contrast, and you can fit a deceivingly large amount of graphics on there.

At the heart of the module is a powerful single-chip CMOS OLED driver controller – SSD1306, which handles all the RAM buffering, so that very little work needs to be done by your ESP8266. Also the operating voltage of the SSD1306 controller is from 1.65V to 3.3V – Perfect for interfacing with 3.3V microcontrollers like ESP8266.

Regardless of the size of the OLED module, the SSD1306 driver has a built-in 1KBGraphic Display Data RAM (GDDRAM) for the screen which holds the bit pattern to be displayed. This 1K memory area is organized in 8 pages (from 0 to 7). Each page contains 128 columns/segments (block 0 to 127). And each column can store 8 bits of data (from 0 to 7). That surely tells us we have

Next, Connect the SCL pin to the I2C clock D1 pin on your NodeMCU and connect the SDA pin to the I2C data D2pin on your NodeMCU. Refer to ESP8266 NodeMCU Pinout.

The library allocates 1KB (128×64)/8 bits) of memory from ESP8266 as buffer. So, it can manipulate the screen buffer and then perform a bulk transfer from the ESP8266’s memory to the internal memory of the SSD1306 controller.

Adafruit’s SSD1306 Library isn’t set up for the 128×64 OLED displays (the one we are using right now). The display size must be changed in the Adafruit_SSD1306.h header file to make it work for us. If it is not changed, an error message saying #error (“Height incorrect, please fix Adafruit_SSD1306.h!”);may appear when attempting to verify the example sketch in the Arduino IDE:

In order to change the Adafruit_SSD1306.h header file, open your sketchbook location. It’s generally My Documents > Arduino. Now go to libraries > Adafruit_SSD1306

Open Adafruit_SSD1306.h file in a text editor. Scroll down the file to find the section with the SSD1306 Displays or directly go to line no. 73. Comment out #define SSD1306_128_32 and uncomment #define SSD1306_128_64 so that the code in this section looks like this:

The sketch starts by including four libraries viz. SPI.h, Wire.h, Adafruit_GFX.h and Adafruit_SSD1306.h. Although SPI.h library is not required for I2C OLED displays, we need to add it for the sake of compiling our program.

Next, we need to create an object of Adafruit_SSD1306.h. The Adafruit_SSD1306 constructor accepts ESP8266 pin number to which reset pin of the display is connected. As the OLED display we are using doesn’t have a RESET pin, we will send –1 to the constructor so that none of the ESP8266 pins is used as a reset for the display.

In setup function: we need to initialize the OLED object using begin() function. The function takes two parameters. First parameter SSD1306_SWITCHCAPVCC turns the internal charge pump circuitry ON while second parameter provides I2C address of the OLED display. I2C address of such OLED display module is generally 0x3C. It’s fixed and cannot be changed.

In order for the library to perform extremely fast mathematical operations on the screen buffer (more than 100 frames per second), calls to the print functions do not immediately transfer the contents of screen buffer to the SSD1306 controller. A display() command is required to instruct the library to perform the bulk transfer from the screen buffer in the ESP8266 to the internal memory of the SSD1306 controller. As soon as the memory is being transferred, the pixels corresponding to the screen buffer will show up on the OLED display.

Characters are rendered in the ratio of 7:10. Meaning, passing font size 1 will render the text at 7×10 pixels per character, passing 2 will render the text at 14×20 pixels per character and so on.

Numbers can be displayed on the OLED display by just calling print() or println() function. An overloaded implementation of these functions accepts 32-bit unsigned int, so you can only display numbers from 0 to 4,294,967,295.

The print() & println() functions has optional second parameter that specifies the base (format) to use; permitted values are BIN (binary, or base 2), OCT (octal, or base 8), DEC (decimal, or base 10), HEX (hexadecimal, or base 16). For floating point numbers, this parameter specifies the number of decimal places to use. For example:

You can draw triangle on the display by using drawTriangle(x0, y0, x1, y1, x2, y2, color) function. The function takes seven parameters viz. 3 X & Y coordinates of vertices of triangle and color. (X0,y0) represents top vertex, (x1,y1) represents left vertex and (x2,y2) represents right vertex.

This last example shows how to draw bitmap images to the OLED Display. This is useful for creating splash screens of company logos, making sprites or just creating fun graphics for displaying information. Copy the following code, paste it into the Arduino IDE and click upload.

But, before we can call the drawBitmap() function, we first need an image to draw. Remember, the screen resolution of the OLED display is 128×64 pixels, so images larger than that will not display correctly. To get a correctly sized image, you can use your favorite drawing programs like Inkscape, Photoshop, Paint, etc., setting the canvas size to 128×64 pixels.

Once you have a bitmap, it’s time to convert it into an array that the SSD1306 OLED controller can understand. This can be done using two ways: Online method using image2cpp and Offline method using LCD Assistant.

There’s an online application called image2cpp – http://javl.github.io/image2cpp/ which can convert your image into an array. Image2cpp is newer and much more powerful than LCD Assistant (later solution). It will allow you to:

The dimensions of your image will populate in Canvas size option under Image settings. If you have selected bigger image than 128×64, change it to 128×64 and select proper Scaling option. You can view the output in Preview section.

Once you are satisfied with the outcome, you can proceed generating the data array. Simply select Code output format as Arduino Code and click on Generate code button.

That’s it. The byte array of your bitmap will be generated. You can use the output directly with our example code. Just be sure to name it appropriately. Then call your array inside the drawBitmap() function.

There’s another application called LCD assistant – http://en.radzio.dxp.pl/bitmap_converter/ which can convert your bitmap image into data array. It’s not as powerful as image2cpp but still popular among hobbyists.

To start with, you need to convert you image into 128×64 1-bit monochrome bitmap. You can use your favorite drawing programs like Inkscape, Photoshop, Paint, etc. to do it, just like we did in MS paint.

Hi, in this tutorial we will see how to control electrical devices like fan, light, etc., to turn on and off using esp8266 from a web browser. if you are bored with a dedicated device controller like an app or an remote which will be available for only one particular device but using this method all the device which support web browsing will be act as a controller for us.

Components that you need for completing this project are very simple, you need to have an esp8266 wifi module and a relay, make sure you buying a 5v relay which very easy to use with esp chips doesn"t require external supply too. we can make use of the Vin pin of the nodemcu or if you are using a generic chip, you need to supply an external 5v to the relay.

Copy the below arduino code and paste into your Arduino IDE and upload the program to your nodemcu or any other esp devices that you are using, make sure to choose the correct port and device name from the board. also don"t forget to change the SSID and password to your Wi-fi settings.

This program for the esp8266 wrote to return the status of the device , which will in turn notify us with the device state in the browser which will also make the user to know which device has currently turned on or off.

if you like the above tutorial and if you want try out with cool projects you can also check this link here , that"s the amazon book link where you can use that book to make IoT with Esp8266 or Nodemcu, that books gives you basic coverage on how to do simple things and get yourself started with arduino and goes on developing projects like sending data to webserver and creating a webserver, uploading and controlling data from a webpage, how to interface TFT LCD and I2C devices and many more things can find on the link.

For an upcoming new project I wanted a colour (UK spelling) LCD screen (ideally OLED), 256×256 (or greater) resolution and nice and cheap. It was not an easy 2 minute task. There were no OLED screens offering what I wanted (that I could see at the time). So compromises were made, in the end I purchased a 128×128 pixel screen (none OLED) for around $3.50 (£3.20, 3.50 Euro). Not as cheap as I thought I might get one for but the cheapest I could find. There were a lot of sellers offering this screen and it’s shown below.

For my new project (after the Space Invaders one, see https://www.xtronical.com/programming-series-space-invaders-on-arduino/), I wanted a screen where I could directly port the Arcade graphics and screen layout without too much messing about re-designing graphics. But for the price point I wanted this proved impossible. Most arcade games of the early 80’s did not go above 256 pixels in any give direction so porting the graphics should be easy I thought. At half the resolution I hope that transferring the graphics will not be too tedious and that in most cases I can simply reduce the number of pixels in each image by half.

Due to the planned game being more advanced than Space Invaders I needed a processor with more memory and speed than the Arduino could offer. Enter the ESP8266 processors which offer faster speeds and lots and lots more memory. Wifi is also available but will not be required for this project unless we implemented a World High Score Table perhaps! There are newer versions, ESP32, available with even more power but are more expensive and we don’t need that level of performance for this project. I’m using a NodeMCU from Lolin, which is basically a breakout board for the ESP8266 so that you can use it easily on breadboards or small production runs using through hole.

Connections – very careful now!Looking at the back we can see +3v3 (this screen can be powered from 5v as well), several grounds (Gnd) and SCL/SDA. This shouldmean that this device is an I²C device and can be easily connected to our Arduino. Err… Think  again. This screen gave me no end of problems as connecting it to the  I²C connections and running any demo I could find on the internet did not get anything on the display. I went back and looked at the listing for this device, it stated SPI Bus not I²C ! So it began to become apparent that this screen had an SPI interface. SCL and SDA would logically seem to be SPI clock and data (MOSI) respectively but other pin labels didn’t match normal SPI protocol labels. Reading several resources for other different screens and looking at the source code for the examples in the Arduino IDE Examples library lead me to find the correct connections to power and use this screen.

Power is self explanatory. LED adds a little extra brightness to the screen but it does still work if not connected. I’ve seen resistors added in series here and even variable ones to vary the brightness but I’ve ran it directly connected on this screen with no issues and wouldn’t want it dimmer as its not ultra bright. It is actually on even when not connected giving adequate brightness in my opinion. SCL is the SPI clock and goes to the NodeMCU’s hardware SPI pin (pin D5). SDA is actually the SPI MOSI connection and goes to the NodeMCU’s SPI MOSI pin (D7). RS is a Regsiter Select pin for ST7735 driver chips, this maps to a variable called TFT_DC in the Adafruitcode (explained later) that I was using for testing. This controls whether we are sending a command to the ST7735 chip or actual data. I think that Adafruit call it DC meaning Data Control, but I’m not sure. On some boards it may even be referred to as A0. For our purposed we connect it to D4. RST is the screen reset and and is connected to pin D3. These last two can connect to any NodeMCU pins that are not used for other functions. CS is Chip Select (usually referred to as Slave Select in the SPI protocol) and again can connect to any pin but I use D2. If this is pulled low then this device can receive or send data on the SPI bus. If only one device in your design you could pull this low permanently and not use D2.

Driver CodeWhen presented with this board (as mentioned above) it was difficult to work out where wires should go and what driver software I needed for the display. Looking at the solitary chip on the board and Googling revealed nothing. So I went back to the sellers listing and found buried deep in a sub-page description the phrase “7735 drive”. Googling this revealed Adafruit had written some drivers for this chip for a board they had created (which also had an SD card slot on it as well). It was not surprising I didn’t find the 7735 chip on the board as this chip is designed to by embedded onto the back of the screen. It was being armed with this source code and other web pages dealing with different chip sets but similar displays that I managed to work out (with a little trial and error) the connections talked about previously above. Initially I used the Adafruit driver code but gave issues with this screen (as it was designed to work with the one they sell). Look below.

Fixing the ST7735 driver to work with this screen.So we have some work to do still to make this work well with our display. The driver we have used to get this up and running was not designed for this display exactly. Things appear clipped and off screen. There were other issues with colour (i.e. red was blue and blue was red amongst other colour problems) and other graphics routines were not correct. I won’t bore you with all the tiny re-writes I did but just supply you with the new driver for this particular display. This driver is very specific, i.e. only targeting this display and resolution but it may well work with many other similar displays. At the time of writing I have no other displays to test with but will be expanding the driver code as and when required. The full driver code is available from the link below, add it into your Arduino in the usual manner (Adding libraries to the Arduino IDE.)

Load up the example code that should now be available at “Files->Examples->XTronical ST7735 Library->GraphicsTestESP8266”. This is basically the Adafruit example with just some tiny changes (It goes through all the tests for each rotational position of the screen) so that it uses the new driver file and slightly altered initialisation routine.

There is an issue with the line drawing routine within the Adafruit GFX library, so this part of the original demo was removed. Basically it forces the NodeMCU to reset. As I’m not going ot be using this I’ve decided for now to ignore this issue.

After two theory-loaded blog posts about handling data array-like in strings (Strings, arrays, and the less known sp(lit)str(ing) function and Strings & arrays - continued) which you are highly recommended to read before continuing here, if you haven"t already, it"s big time to see how things work in practice! We"ll use a string variable as a lookup lookup table containing data of one single wave period and add this repeatedly to a waveform component until it"s full.A few weeks ago, I wrote this article about using a text variable as an array, either an array of strings or an array of numbers, using the covx conversion function in addition for the latter, to extract single elements with the help of the spstr function. It"s a convenient and almost a "one fits all" solution for most use cases and many of the demo projects or the sample code attached to the Nextion Sunday Blog articles made use of it, sometimes even without mentioning it explicitly since it"s almost self-explaining. Then, I got a message from a reader, writing: "... Why then didn"t you use it for the combined sine / cosine lookup table in the flicker free turbo gauge project?"105 editions of the Nextion Sunday blog in a little over two years - time to look back and forth at the same time. Was all the stuff I wrote about interesting for my readers? Is it possible at all to satisfy everybody - hobbyists, makers, and professionals - at the same time? Are people (re-)using the many many HMI demo projects and code snippets? Is anybody interested in the explanation of all the underlying basics like the algorithms for calculating square roots and trigonometric functions with Nextion"s purely integer based language? Are optimized code snippets which allow to save a few milliseconds here and there helpful to other developers?Looking through the different Nextion user groups on social networks, the Nextion user forum and a few not so official but Nextion related forums can be surprising. Sometimes, Nextion newbies ask questions or have issues although the required function is well (in a condensed manner for the experienced developer, I admit) documented on the Nextion Instruction Set page, accessible through the menu of this website. On top of that, there is for sure one of my more than 100 Sunday blog articles which deals not only with that function, but goes often even beyond the usual usage of it. Apparently, I should sometimes move away from always trying to push the limits and listen to the "back to the roots!" calls by my potential readers...Do you remember the (almost) full screen sized flicker free and ultra rapid gauge we designed in June? And this without using the built-in Gauge component? If not, it"s time to read this article first, to understand today"s improvements. The June 2022 version does its job perfectly, the needle movement is quick and smooth, and other components can be added close to the outer circle without flickering since there is no background which needs constantly to be redrawn. But there was a minor and only esthetic weak point: The needle was a 1px thin line, sometimes difficult to see. Thus, already a short time after publishing, some readers contacted me and asked if there were a way to make the needle thicker, at least 2 pixels.Recently, when playing with a ESP32 based NodeMCU 32S and especially with its WiFi configuration, I did as (I guess) everybody does: I loaded an example sketch to learn more about the Wifi library. When you set up the ESP32 as an access point, creating its own wireless network, everything is pretty straightforward. You can easily hard code the Wifi name (SSID) and the password. But what about the client mode ? Perhaps one needs to use it in different environments. And then, a hard coded network name and password are definitively not the best solution. Thus, I thought, why not use a Nextion HMI for a dynamic WiFi setup functionality?

Simply put: that TFT requires a lot of GPIO pins - 10 at an absolute bare minimum, but better if you have more available. The ESP8266 doesn"t have many IO pins - and some of them are very sensitive about what they can be connected to without affecting the boot process.

If you are careful with your GPIO selection it may be possible to work with that screen. There are no specific requirements for what pins need to be connected to where (as far as hardware functionality goes), so it"s up to you to find the right combination that doesn"t cripple the boot process (stay away from GPIOs 0, 2 and 15 if you can).

by Floris Wouterlood – The Netherlands – May 2, 2021 — IntroductionThe ESP8266 is a well performing microcontroller chip that is fully Arduino compatible. Its WiFi capability make…