arduino lcd display hello world made in china

hey all i am new to arduino.. to make a loooong story short, i need help with my very first code!! it is the lcd arduino, i compiled a sketch and uploaded to my board, and it is very strange.. i can print numbers but not any kind of text or letters.. so hello world just wont print to the lcd.. if i try to use ANY kind of letters, it wont work.. only dislays weird lines and question marks.. but if i enter and numbers in the lcd.print it WORKS FINE!! hmmm anyway, here is my code (sketch) any help would be great !! thanks::

In this tutorial, we will learn how to make custom characters on an I2C LCD display. Click hereto refer to my previous blog and learn about the I2C LCD display basics. Custom characters are non-original figures created from original parts. You can create different figures such as hearts, squares, rectangles, and more.

The I2C LCD display is made up of blocks which are fundamentally 5 dots in a row and 8 dots in a column. The LCD has 32 of those blocks and it makes up the 16X2 LCD. You can program each of the blocks to make any figure you want.

The picture above shows the organization of a single block that is used to make up LCD. To create a custom character, we need to define which dot out of the 5 x 8 block has to be lighted up. This can be done by writing the binary equivalent of each row and column. Each dot is either on or off. We can create figures by turning them off or on. Use this website below to get the understanding on create figures.

The program is pretty simple. We are declaring the variable smileyFace which is array of type byte. This array will contain 8 bytes, one for each row in our block. The block is made up by 5X8 dots as mentioned before.We can program those dots by turning them on or off. In this code we write 0 for off and 1 is for on. Writing that, you can create any figure you want! In setup function, we simply turn on the background light of the LCD. Then, we set the cursor to the place you want to display your text, and display it by using the setCursor function of the library.

Hello friend welcome to “Techno-E-Solution” in this article we are going to learn how to connect LCD display with Arduino Uno and print "Hello World!" on LCD using Arduino Uno. The 16x2 LCD is most popular LCD in electronics projects. In upcoming project we need this display in our project so it"s the beginners level tutorial learn this tutorial with fun. So friends let"s get started..........

Connecting an LCD to your Raspberry Pi will spice up almost any project, but what if your pins are tied up with connections to other modules? No problem, just connect your LCD with I2C, it only uses two pins (well, four if you count the ground and power).

In this tutorial, I’ll show you everything you need to set up an LCD using I2C, but if you want to learn more about I2C and the details of how it works, check out our article Basics of the I2C Communication Protocol.

There are a couple ways to use I2C to connect an LCD to the Raspberry Pi. The simplest is to get an LCD with an I2C backpack. But the hardcore DIY way is to use a standard HD44780 LCD and connect it to the Pi via a chip called the PCF8574.

The PCF8574 converts the I2C signal sent from the Pi into a parallel signal that can be used by the LCD. Most I2C LCDs use the PCF8574 anyway. I’ll explain how to connect it both ways in a minute.

I’ll also show you how to program the LCD using Python, and provide examples for how to print and position the text, clear the screen, scroll text, print data from a sensor, print the date and time, and print the IP address of your Pi.

Connecting an LCD with an I2C backpack is pretty self-explanatory. Connect the SDA pin on the Pi to the SDA pin on the LCD, and the SCL pin on the Pi to the SCL pin on the LCD. The ground and Vcc pins will also need to be connected. Most LCDs can operate with 3.3V, but they’re meant to be run on 5V, so connect it to the 5V pin of the Pi if possible.

If you have an LCD without I2C and have a PCF8574 chip lying around, you can use it to connect your LCD with a little extra wiring. The PCF8574 is an 8 bit I/O expander which converts a parallel signal into I2C and vice-versa. The Raspberry Pi sends data to the PCF8574 via I2C. The PCF8574 then converts the I2C signal into a 4 bit parallel signal, which is relayed to the LCD.

Now we need to install a program called I2C-tools, which will tell us the I2C address of the LCD when it’s connected to the Pi. So at the command prompt, enter sudo apt-get install i2c-tools.

Now reboot the Pi and log in again. With your LCD connected, enter i2cdetect -y 1 at the command prompt. This will show you a table of addresses for each I2C device connected to your Pi:

We’ll be using Python to program the LCD, so if this is your first time writing/running a Python program, you may want to check out How to Write and Run a Python Program on the Raspberry Pi before proceeding.

The function mylcd.lcd_display_string() prints text to the screen and also lets you chose where to position it. The function is used as mylcd.lcd_display_string("TEXT TO PRINT", ROW, COLUMN). For example, the following code prints “Hello World!” to row 2, column 3:

On a 16×2 LCD, the rows are numbered 1 – 2, while the columns are numbered 0 – 15. So to print “Hello World!” at the first column of the top row, you would use mylcd.lcd_display_string("Hello World!", 1, 0).

You can create any pattern you want and print it to the display as a custom character. Each character is an array of 5 x 8 pixels. Up to 8 custom characters can be defined and stored in the LCD’s memory. This custom character generator will help you create the bit array needed to define the characters in the LCD memory.

The code below will display data from a DHT11 temperature and humidity sensor. Follow this tutorial for instructions on how to set up the DHT11 on the Raspberry Pi. The DHT11 signal pin is connected to BCM pin 4 (physical pin 7 of the RPi).

By inserting the variable from your sensor into the mylcd.lcd_display_string() function (line 22 in the code above) you can print the sensor data just like any other text string.

These programs are just basic examples of ways you can control text on your LCD. Try changing things around and combining the code to get some interesting effects. For example, you can make some fun animations by scrolling with custom characters. Don’t have enough screen space to output all of your sensor data? Just print and clear each reading for a couple seconds in a loop.

It was an afternoon, I had pulled out an Arduino Leonardo and an LCD Keypad Shield. I wanted to build something Wi-Fi connected, so I grabbed an ESP8266 Wi-Fi Shield as well and thought I’d be on my way. Even if the AT-command set mode wasn’t great, I was only looking to build something simple.

Getting a little ahead of myself, I had no stackable pin headers, so I decided to stuff the Wi-Fi Shield behind the LCD Keypad Shield and just solder it to the slightly-long headers it already had. That went just fine and so I tried snapping it onto the Leonardo – aside from a slight port-clearance issue, it sat “well enough”.

After tearing a few (useless) pads off the board and still resorting to a heat-gun, I managed to separate the two but not without some casualties – the LCD had taken a good dose of heat resulting in some noticeable discolouration, so I don’t know if that was still good or not.

Going into salvage mode, I was still convinced the ESP8266 Wi-Fi Shield would be of use, so I decided to try programming it directly using the ESP8266 Arduino Core and an FTDI cable. I could get a response – I could program the chip to blink an LED, but absolutely anything Wi-Fi related was not working at all. I checked the WiFi Mode was being set correctly, and even tried scripts to disable and re-enable it to no avail. My AP was also telling me that it never even saw a connection attempt.

I still had a really beaten up LCD shield module that had been through many ordeals and seemed to be bin material. But then, I thought I might as well give it a go – by desoldering as much of the broken pins out and replacing just the pins necessary, I decided to give it a shot.

In order to do this, I had to write a program to write some data to the screen. I could have stuck with “Hello World”, but where’s the fun in that? It wouldn’t test the character generator much …

The LCD was still alive, but with a slight bright spot on the top row. That’s quite amazing. But then, I thought it would be nice to make something less “random and confusing” – why not make something aesthetically eye-catching.

Keeping myself occupied for the afternoon, I decided that I would take the random-character-sketch and instead do something a little less random and a little more artistic. That’s when I came up with the idea of illustrating “Words vs Numbers” on an LCD. As I had an old Arduino Mega 2560 that had a bunch of blown I/O pins due to an accident with some scrap wire and an even larger 20×4 LCD that was doing absolutely nothing for the past six years, I decided it would be nice to just cobble it together for some fun.

The new project would:Put numbers in random positions on the display on a regular basis, rather than doing random characters sequentially as my LCD test did. This would create a sparkling that would look like “noise” on a background of numbers that might be somewhat reminiscent of The Matrix.

Write random words to random positions on the display on a regular basis. This would be taken from a list of common English words – fitting as many in as possible to increase variety.

With some white coloured hook-up wire (as that was what I had left), a half-damaged Arduino Mega 2560 clone board, a 10kohm precision trimpot, an old LCD display and a lot of hot glue … we have this monstrosity.

This code was kept as simple as possible and was something I ended up writing within half an hour. The idea is to use LiquidCrystal library for parallel LCD interfacing, using random() to generate the necessary random values seeded by an analogRead() value from an unconnected pin. The loop sets the cursor to a random position within the LCD and writes a random character within the range (defined as numbers) to that position. It delays a fixed amount of time, and counts every loop. After a fixed number of loops, we turn on the “blink” feature so the block cursor shows (to make the word printing more obvious) and pull a random string from the string table in PROGMEM. This is written to a random position on the screen character by character (ensuring it fits into the screen), followed by a five-times-length delay to give the eye some time to identify and read the word before it is “destroyed” by further random writes. The blink feature is turned off when returning back into the random number writing loop.

For larger microcontrollers, such as the ATMEGA1280/256o used in the Mega boards, they have 128/256kB of memory minus some for the bootloader. Unfortunately, there is a problem with using all of this memory as pointers are 16-bit in the Arduino code, resulting in a hard 64kB limit in pointers. Exceeding this results in code that doesn’t execute properly through to assembler errors. The solution for this is to apparently use far-pointers, which don’t seem nicely supported, so I’ve capped the number of words to 6500 words instead from Google’s corpus to fit within this space limit.

The full code for both an Arduino Leonardo (or other 32kB microcontrollers) and Arduino Mega 1280/2560 (or 64kB+ microcontrollers) can be downloaded: randomlcd.zip

It’s not something really amazing or perhaps even unique, but more a result of a lot of frustration. Borne out of some code I wrote to just test an LCD which I had tortured, I decided to extend it with the help of a few online corpuses to print random words over a sea of random numbers. But now that I’ve built it, I do like it – it seems rather visually interesting at times to just pick a word out from the “sea” of numbers before it disappears.

- You"ve connected your LCD. Now it"s time to see if your Arduino can control it. We"ll work on the sketch for our game soon, but now we just want to see if the LCD works properly. So let"s start with what"s called a Hello World sketch to see if we can get anything to appear on the display. We can write a sketch from scratch, but libraries often provide example sketches. So let"s go to the Arduino IDE to see if there"s anything we can use from the liquid crystal library to get started. So now on the desktop, we can open Arduino. Wait for it to initialize. And now if we go up to File, examples, liquid crystal we can see that there"s a Hello World sketch. So let"s open that. We"ll look more closely at the sketch in a second. But for now let"s just run it to see if it works. But first, make sure you"ve selected the correct board the Arduino Uno, and you"ve selected the USB port. Now to run the sketch, just click on the run…

The ST7789 TFT module contains a display controller with the same name: ST7789. It’s a color display that uses SPI interface protocol and requires 3, 4 or 5 control pins, it’s low cost and easy to use. This display is an IPS display, it comes in different sizes (1.3″, 1.54″ …) but all of them should have the same resolution of 240×240 pixel, this means it has 57600 pixels. This module works with 3.3V only and it doesn’t support 5V (not 5V tolerant).

The ST7789 display module shown in project circuit diagram has 7 pins: (from right to left): GND (ground), VCC, SCL (serial clock), SDA (serial data), RES (reset), DC (or D/C: data/command) and BLK (back light).

As mentioned above, the ST7789 TFT display controller works with 3.3V only (power supply and control lines). The display module is supplied with 3.3V (between VCC and GND) which comes from the Arduino board.

To connect the Arduino to the display module, I used voltage divider for each line which means there are 4 voltage dividers. Each voltage divider consists of 2.2k and 3.3k resistors, this drops the 5V into 3V which is sufficient.

The first library is a driver for the ST7789 TFT display which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries …, in the search box write “st7789” and install the one from Adafruit).

The Wio Terminal is a SAMD51-based microcontroller with Wireless Connectivity powered by Realtek RTL8720DN that’s compatible with Arduino and MicroPython. Currently, wireless connectivity is only supported by Arduino. It runs at 120MHz (Boost up to 200MHz), 4MB External Flash and 192KB RAM. It supports both Bluetooth and Wi-Fi providing backbone for IoT projects. The Wio Terminal itself is equipped with a 2.4” LCD Screen, onboard IMU(LIS3DHTR), Microphone, Buzzer, microSD card slot, Light sensor, and Infrared Emitter(IR 940nm). On top of that, it also has two multifunctional Grove ports for Grove Ecosystem and 40 Raspberry pi compatible pin GPIO for more add-ons.

Highly Integrated DesignMCU, LCD, WIFI, BT, IMU, Microphone, Speaker, microSD Card, Light Sensor, 5-Way Switch, Infrared Emitter (IR 940nm), Crypto-authentication Ready

Select the serial device of the Wio Terminal board from the Tools -> Port menu. This is likely to be COM3 or higher (COM1 and COM2 are usually reserved for hardware serial ports). To find out, you can disconnect your Wio Terminal board and re-open the menu; the entry that disappears should be the Arduino board. Reconnect the board and select that serial port.

If you are not able to upload the sketch, mostly it"s because Arduino IDE was not able to put Wio Terminal to bootloader mode. (Because MCU was halted or your program handling USB,) Workaround is putting your Wio Terminal to bootloader mode manually, as shown in FAQ.

This is very useful when Wio Terminal crashes or somehow USB serial is not showing up in Arduino IDE. Slide the switch twice very quickly, as followed:

After you install seeed-arduinocore-samd, the core will download some library files to drive different devices at the same time, such as TFT_eSPI.h, etc. When you upload the program, an error will occur and the compiler will prompt you that multiple library files are found. E.g:

If you use a seeed-SAMD device, please select and use the library file in the seeed folder and move the conflicting library file out of the arduino library.

In this article, you will learn how to use TFT LCDs by Arduino boards. From basic commands to professional designs and technics are all explained here.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

Size of displays affects your project parameters. Bigger Display is not always better. if you want to display high-resolution images and signs, you should choose a big size display with higher resolution. But it decreases the speed of your processing, needs more space and also needs more current to run.

After choosing the right display, It’s time to choose the right controller. If you want to display characters, tests, numbers and static images and the speed of display is not important, the Atmega328 Arduino boards (such as Arduino UNO) are a proper choice. If the size of your code is big, The UNO board may not be enough. You can use Arduino Mega2560 instead. And if you want to show high resolution images and motions with high speed, you should use the ARM core Arduino boards such as Arduino DUE.

In electronics/computer hardware a display driver is usually a semiconductor integrated circuit (but may alternatively comprise a state machine made of discrete logic and other components) which provides an interface function between a microprocessor, microcontroller, ASIC or general-purpose peripheral interface and a particular type of display device, e.g. LCD, LED, OLED, ePaper, CRT, Vacuum fluorescent or Nixie.

The display driver will typically accept commands and data using an industry-standard general-purpose serial or parallel interface, such as TTL, CMOS, RS232, SPI, I2C, etc. and generate signals with suitable voltage, current, timing and demultiplexing to make the display show the desired text or image.

The LCDs manufacturers use different drivers in their products. Some of them are more popular and some of them are very unknown. To run your display easily, you should use Arduino LCDs libraries and add them to your code. Otherwise running the display may be very difficult. There are many free libraries you can find on the internet but the important point about the libraries is their compatibility with the LCD’s driver. The driver of your LCD must be known by your library. In this article, we use the Adafruit GFX library and MCUFRIEND KBV library and example codes. You can download them from the following links.

You must add the library and then upload the code. If it is the first time you run an Arduino board, don’t worry. Just follow these steps:Go to www.arduino.cc/en/Main/Software and download the software of your OS. Install the IDE software as instructed.

By these two functions, You can find out the resolution of the display. Just add them to the code and put the outputs in a uint16_t variable. Then read it from the Serial port by Serial.println(); . First add Serial.begin(9600); in setup().

First you should convert your image to hex code. Download the software from the following link. if you don’t want to change the settings of the software, you must invert the color of the image and make the image horizontally mirrored and rotate it 90 degrees counterclockwise. Now add it to the software and convert it. Open the exported file and copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are sizes of image. you can change the color of the image in the last input.

Upload your image and download the converted file that the UTFT libraries can process. Now copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are size of the image.

In this template, We converted a .jpg image to .c file and added to the code, wrote a string and used the fade code to display. Then we used scroll code to move the screen left. Download the .h file and add it to the folder of the Arduino sketch.

In this template, We used sin(); and cos(); functions to draw Arcs with our desired thickness and displayed number by text printing function. Then we converted an image to hex code and added them to the code and displayed the image by bitmap function. Then we used draw lines function to change the style of the image. Download the .h file and add it to the folder of the Arduino sketch.

In this template, We created a function which accepts numbers as input and displays them as a pie chart. We just use draw arc and filled circle functions.

In this template, We added a converted image to code and then used two black and white arcs to create the pointer of volumes.  Download the .h file and add it to the folder of the Arduino sketch.

In this template, We added a converted image and use the arc and print function to create this gauge.  Download the .h file and add it to folder of the Arduino sketch.

In this template, We display simple images one after each other very fast by bitmap function. So you can make your animation by this trick.  Download the .h file and add it to folder of the Arduino sketch.

In this template, We just display some images by RGBbitmap and bitmap functions. Just make a code for touchscreen and use this template.  Download the .h file and add it to folder of the Arduino sketch.

Are you on the lookout for a good Arduino simulator? Wondering what an Arduino simulator is? We’ve gotten a lot of questions about Arduino simulators, and if a good simulator exists, so keep watching to find out more!

What does that actually mean? Let’s look at an example. Now some people have different interpretations of what the famous “Hello World” circuit is.  Some say it’s your first project where you create a simple blinking LED circuit; others claim it’s when you have an LCD display that says “Hello world!”

So we’ve setup the circuit, we’ve programmed the code in the Arduino IDE, we’ve uploaded it, and now we have a real world, physical circuit that blinks the LED. This took about 6 minutes to construct.

Next we’ll use the free online Arduino simulator software at TinkerCAD. In about 2 minutes we’ve created exactly the same circuit, we’ve used the same exact code, and after hitting the “start simulation button”, we have a virtual version of exactly the same circuit. That is some serious efficiency!

It’s much easier to track down hardware / wiring errors in the simulator. It can be very difficult to visualize which wires are connected to which pins on a busy breadboard, but if you get it right in the simulator, then recreating it in the real world goes much smoother.

One thing to note: you can select Components > Starters > Arduino and here you can access a bunch of premade circuits which are called assemblies. You can click and drop the “Blink” assembly, which will provide all the necessary components, as well as the code to make the circuit run.

If you click “Start Simulation” you will see this circuit functions as advertised. So let’s create it from scratch instead.  The first thing we will want to do is make sure we have components placed in our project. Type in “Arduino” in the components side menu and then click and drop the UNO3.

Lastly we will wire it up. You do not find wires in the component list, you simply click on either the breadboard or the Arduino pins with the left mouse button and a wire begins.

So that’s how you build the circuit.  Let’s look at the code. You can see it’s already preloaded with a sketch because we had previously selected the “Blink” starter assembly. You can also see it’s in a format that may seem a little unusual, “block view“. You can mess around with this view if you want, but we typically like to view the code in “text view” which is the same as the official Arduino IDE.

If you select “Projects”, then “Show all Arduino”, you can see various projects at the bottom with the green backgrounds. All of these projects correspond to the starter projects that are included in the the official Arduino.CC starter kit, which is super helpful if you have that kit and want to follow along.

How do you use the simulator? Do you like creating projects virtually first, do you like to dive right into the physical world? Let us know in the comments below, we’d really appreciate it. Have a great day!