raspi lcd display free sample
This repository contains all the code for interfacing with a 16x2 character I2C liquid-crystal display (LCD). This accompanies my Youtube tutorial: Raspberry Pi - Mini LCD Display Tutorial.
During the installation, pay attention to any messages about python and python3 usage, as they inform which version you should use to interface with the LCD driver. For example:
It is possible to define in CG RAM memory up to 8 custom characters. These characters can be prompted on LCD the same way as any characters from the characters table. Codes for the custom characters are unique and as follows:
For example, the hex code of the symbol ö is 0xEF, and so this symbol could be printed on the second row of the display by using the {0xEF} placeholder, as follows:
Rather than plug your Raspberry Pi into a TV, or connect via SSH (or remote desktop connections via VNC or RDP), you might have opted to purchase a Raspberry Pi touchscreen display.
Straightforward to set up, the touchscreen display has so many possibilities. But if you"ve left yours gathering dust in a drawer, there"s no way you"re going to experience the full benefits of such a useful piece of kit.
The alternative is to get it out of the drawer, hook your touchscreen display to your Raspberry Pi, and reformat the microSD card. It"s time to work on a new project -- one of these ideas should pique your interest.
Let"s start with perhaps the most obvious option. The official Raspberry Pi touchscreen display is seven inches diagonal, making it an ideal size for a photo frame. For the best results, you"ll need a wireless connection (Ethernet cables look unsightly on a mantelpiece) as well as a Raspberry Pi-compatible battery pack.
In the example above, Belkin WeMo switches and a Nest thermostat are manipulated via the Raspberry Pi, touchscreen display, and the InControlHA system with Wemo and Nest plugins. ST:TNG magic comes from an implementation of the Library Computer Access and Retrieval System (LCARS) seen in 1980s/1990s Star Trek. Coder Toby Kurien has developed an LCARS user interface for the Pi that has uses beyond home automation.
Building a carputer has long been the holy grail of technology DIYers, and the Raspberry Pi makes it far more achievable than ever before. But for the carputer to really take shape, it needs a display -- and what better than a touchscreen interface?
Now here is a unique use for the Pi and its touchscreen display. A compact, bench-based tool for controlling hardware on your bench (or kitchen or desk), this is a build with several purposes. It"s designed to help you get your home automation projects off the ground, but also includes support for a webcam to help you record your progress.
The idea here is simple. With just a Raspberry Pi, a webcam, and a touchscreen display -- plus a thermal printer -- you can build a versatile photo booth!
Various projects of this kind have sprung up. While the versions displayed above uses a thermal printer outputting a low-res image, you might prefer to employ a standard color photo printer. The wait will be longer, but the results better!
How about a smart mirror for your Raspberry Pi touchscreen display project? This is basically a mirror that not only shows your reflection, but also useful information. For instance, latest news and weather updates.
Naturally, a larger display would deliver the best results, but if you"re looking to get started with a smart mirror project, or develop your own from scratch, a Raspberry Pi combined with a touchscreen display is an excellent place to start.
Want to pump some banging "toons" out of your Raspberry Pi? We"ve looked at some internet radio projects in the past, but adding in a touchscreen display changes things considerably. For a start, it"s a lot easier to find the station you want to listen to!
This example uses a much smaller Adafruit touchscreen display for the Raspberry Pi. You can get suitable results from any compatible touchscreen, however.
We were impressed by this project over at Hackster.io, but note that there are many alternatives. Often these rely on compact LCD displays rather than the touchscreen solution.
Many home automation systems have been developed for, or ported to, the Raspberry Pi -- enough for their own list. Not all of these feature a touchscreen display, however.
Another great build, and the one we"re finishing on, is a Raspberry Pi-powered tablet computer. The idea is simple: place the Pi, the touchscreen display, and a rechargeable battery pack into a suitable case (more than likely 3D printed). You might opt to change the operating system; Raspbian Jessie with PIXEL (nor the previous desktop) isn"t really suitable as a touch-friendly interface. Happily, there are versions of Android available for the Raspberry Pi.
This is a new Pi Pico display from Waveshare with many more pixels. It is a 2inch LCD display module, designed for Raspberry Pi Pico, with an embedded ST7789VW driver, 65K RGB colours, 320x240 pixels and an SPI interface. A Pi Pico can be plugged into the rear of the screen for very easy connection without any soldering. It sports 4 simple button switches for user input. It is bright, colourful and easy to program. The makers supply an example program (see below), which includes the display driver, making it very easy to get started. The manufacturer"s wiki can be found at:
The 3.5 inch LCD Display is directly pluggable into a Raspberry Pi and perfectly fits various Pi models from B+ to Raspberry Pi 3B+. It is a brilliant alternative for an HDMI monitor. When set up, it behaves as a human-machine interface enabling the user to prototype with the Raspberry Pi device anywhere at any time.
In this tutorial we"ll take you through how to connect a 16x2 LCD display up to your Raspberry Pi using GPIO pins. Being able to display a message on the LCD is not only very cool but can be pretty useful too, for example in this tutorial we"ll cover how to get your LCD display to display the IP address of your raspberry Pi.
For this exercise we are going to control the LCD display using 4-bit mode. Whilst is is possible to connect to it in other ways using I2C or the UART this is the most direct method. In order to control the display in this way will we need to use 6 pins on the GPIO port, 4 data pins and 2 control pins.
Register Select – This toggles the Lcd display between two modes, Command mode (high) and Data mode (low). Command mode gives a Instruction to the LCD. Example – “Clear the display” , “Move cursor to home” etc and Data tells the LCD to display characters.
In order for the LCD to work we will wire the circuit up in a fashion similar to the diagram above, but hold off connecting everything together for now! The list below tells you exactly what the pins on the LCD connect to:
Begin assembling the circuit by inserting the Adafruit cobbler into the breadboard. Remember to straddle the cobbler over the centre of the breadboard so that no two pin is in the same row. Next insert the LCD display into the breadboard. Connect the 5V and GND pins from the cobbler to the top of breadboard and also connect Pins 1, 2, 15 on the LCD and 16 to their respective power rails. Your circuit should look similar to the picture below:
Connect the GPIO ribbon cable from the cobbler to the Pi, if everything is working correctly the back light on the LCD should turn on like on the picture above. If it doesn"t work check everything is wired up correctly
Next wire up the potentiometer. The middle pin of the potentiometer is connected to Pin 3 on the LCD display and the other two pins are connected to ground and 5V (it doesn"t matter which way round). Check the potentiometer is working by twisting the nob until you see boxes appear in the first line of the display like in the picture below:
To get the Python code to run the LCD display we are going to "grab" it from adafruit using GitHub. Make sure your Rasp berry Pi is connected to internet and we"ll use the git command to clone the python code. Run the following commands in the terminal to download the files.
Now we can test the display is working and it is wired up correctly. One of the files we downloaded Adafruit_CharLCD.py contains python class for LCD display control. It also contains a small piece of code so when the program is run it will display a message on the LCD.
If you are using Version 2 of the Raspberry pi you will need to edit the program slightly since pin #21 has now been changed to pin #27. Open the file Adafruit_CharLCD.py with Python or use nano Adafruit_CharLCD.py command to edit the program within the terminal. Go to line 57 of the code and replace:
Feel free to dive into the code of the program and change what"s displayed on the LCD. To do so open the program to edit like before and scroll to the last line of the code:
Simply change what is typed in the brackets after lcd.message() to display the text you want. The command is used to wrap the text onto a new line. A neater way of doing this is to change the last part of the program to look like the following:
This way when you run the program you will be prompted by "type your message here" to enter a message via your keyboard, which will then be displayed on the LCD. This was done by defining a new variable "message" that is equal to the command raw_input(), which allows the user to manually enter text. The part within the brackets of the raw_input() command is simply printed on the computer screen to prompt you what to write.
Getting the LCD display to display some text of your choosing is cool but not that useful. Running the program Adafruit_CharLCD_IPclock_example.py will display the date/time and the IP address of the Pi on the LCD. The program calls upon the methods from the previous program Adafruit_CharLCD.py. Feel free to open the program to look at the coding. To do so open the program in python or use the command sudo nano Adafruit_CharLCD_IPclock_example.pyin the terminal.
As soon as we have this API key, we can move to the hardware configuration and connect the LCD screen to our Raspberry Pi. You should turn the Raspberry Pi off while you make the wire connection.
This hardware connection will make the LCD screen be on full brightness and full contrast. The brightness level is not a problem, but contrast is because we won’t be able to see the characters on the screen.
At this point, we can turn on our Raspberry Pi and we should see the LCD screen alive. With the help of variable resistance we should be able to control the contrast.
In a new folder, run the command npm init -y to set up a new npm package, followed by the command npm install lcd node-fetch to install these 2 necessary dependencies.lcd will be used to communicate with the LCD Screen
Writing on the screen is a piece of cake using the lcd module. This library acts as a layer of abstraction over how we communicate with the device. In this way we don’t need to micro-manage each command individually.
The keys cols and rows represent the number of columns and rows of our LCD display. 16x2 is the one I used in this example. If your LCD has just 8 columns and 1 row, then replace 16 and 2 with your values.
At this point, you can use this function and print something on your display. writeToLcd(0,0,"Hello World") should print the message Hello World on the first row starting from the first column.
ClimaCell provides a lot of weather data information, but also air quality and pollen, fire and other information. The data is vast, but keep in mind that your LCD screen only has 16 columns and 2 rows – that’s just 32 characters.
To print the time in the upper right corner, we must first calculate the starting column so that the text fits snugly. For this we can use the next formula total columns number minus text to display length
The LCD setting is asynchronous, so we must use the method lcd.on() provided by the related library, so we know when the LCD has been initialized and is ready to be used.
Another best practice in embedded systems is to close and free the resources that you use. That’s why we use the SIGNINT event to close the LCD screen when the program is stopped. Other events like this one include:SIGUSR1 and SIGUSR2 - to catch "kill pid” like nodemon restart
From this point you can customize your new device however you want. If you find this weather data important for you (or any other data from ClimaCell, like air pollution, pollen, fire index or road risk), you can create a custom case to put the Raspberry Pi and the LCD display in it. Then after you added a battery you can place the device in your house.
HyperPixel 2.1 Round has all the great features of our other HyperPixels - crisp, brilliant IPS display, touchscreen, and high-speed DPI interface—it"s just rounder! You can use it with any Raspberry Pi with a 40 pin header* but it works particularly nicely with the Pi Zero footprint - we"ve designed it so you can mount a Zero neatly behind it, so you can"t see the Pi when you look at it from the front.
This version of HyperPixel would be great for custom interfaces and control panels - mounted on a wall it would make a really neat, minimalist smart home controller or a stylish "what"s playing" display for your sound system. Everything is pre-soldered and ready to go, just pop it onto your Pi, install our software, and away you go!
HyperPixel 2.1 Round uses a high-speed DPI interface, allowing it to shift 5x more pixel data than the usual SPI interface that these small Pi displays normally use. It has a 60 FPS frame rate and a resolution of approximately 229 pixels per inch (480x480px) on its 2.1" display. The display can show 18-bits of colour (262,144 colours).
The touchscreen variant is capacitive touch, that"s more sensitive and responsive to touch than a resistive touch display, and it"s capable of multi-touch!**
Please note: when installing HyperPixel 2.1 Round onto your Pi make sure not to press down on the screen surface. We recommend putting the screen face down on a soft surface and gently wiggling the Pi to mate with the extended header (or GPIO header). If you need to remove your Hyperpixel, take care not to pull on the edges of the glass display - it"s best to hold on to the rectangular PCB. As the glass edges of this display overhang the PCB they"re quite exposed, so it"s worth being extra careful with them.
With this version of HyperPixel, we"ve separated the display drivers and touch drivers which should hopefully make it easier to incorporate touch interfaces into your own programs. To download and install the display drivers:
Note that you"ll need another display, keyboard, and mouse to install the software, or you could do it remotely over SSH if you set your Pi up headlessly.
Raspberry Pi OS Bullseye includes major changes to how DPI display drivers work - a quick hack to get the screen working (with some loss of rotation/touch functionality) is to comment out dtoverlay=vc4-kms-v3d in boot/config.txt. We"re working on full support for Bullseye, but if you"re after an easy, fully featured Hyperpixel experience you should probably stick with Buster for now: