swapxy tft display free sample

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I recently found a discount code through SlickDeals for $10 off the Elecrow 5" HDMI Touchscreen display for the Raspberry Pi. Since the Raspberry Pi was introduced, I"ve wanted to try out one of these mini screens (touchscreen or no), but they"ve always been prohibitively expensive (usually $60+).

The display is pretty solid, and comes well packed in styrofoam with four standoffs for mounting, a cheap plastic stylus, and a male-to-male HDMI daughter-card. Getting the Pi onto the board is easy enough; I used one standoff through one of the Pi"s mounting holes (on the side with the HDMI plug), then seated the Pi directly on top of the GPIO slot on the display board, so so the HDMI ports would line up perfectly on the other side.

The Elecrow officially supports the Raspberry Pi 3 model B, but I tested it with a 2 model B as well. I didn"t try it with a B+, but the hardware layout should work, so at least the HDMI display would work correctly (not sure about the touchscreen controls). The way the hardware is laid out, you seat the Raspberry Pi directly onto a GPIO socket (it takes up the first 13 sets of GPIO pins—pins 1-26), and then there"s an included HDMI male-to-male daughtercard that slots in nicely to connect the HDMI output of the Pi to the HDMI input on the display.

There"s an extra OTG USB plug on the display if you want to give it a separate power source, but if you plug it straight into the Pi"s GPIO, it will leech off the 5V connection. As long as you have a good 2A power supply for your Pi, though, you shouldn"t have to worry about supplying independent power to the display. In my usage, I only saw the overvolt indicator every now and then (just like I do in normal usage of the Pi 3, since it uses a bit more power than a 2!).

When I first booted the Pi attached to the display, there was a large white area on the right, and only the left portion of the screen was being used by the Pi (it was only using 640x480 of the 800x480 display). To fix this, you have to set a few display options in the configuration file the Raspberry Pi reads during startup to switch certain hardware settings.

Besides being a 800x480 HDMI display, the Elecrow also has a touchscreen overlay that allows simple one-point resistive touch detection on the screen. Note that at best, resistive touch is not nearly as responsive and intuitive as capacitive touch detection, which you"re likely used to on any recent smartphone or tablet screen. But something is better than nothing, when it comes to building simple UIs for "Internet of Things" devices or other fun things.

For ~$30 ($40 without discount), I wasn"t expecting a mind-blowing retina display with excellent glare-reducing coatings and contrast. But I do expect no dead pixels, and at least a crisp, vibrant picture when looking straight on. This screen is "good enough" in that regard, though viewing angles aren"t too great; side to side is okay, but looking down from above or up from below results in a bit of a washed out picture. Also, there is no antireflective coating on the screen, so wherever you use it, you need to be aware of nearby light sources.

So, to summarize the review: this is everything I expected out of a sub-$50 display. It"s nothing like a high-end smartphone display with capacitive touch, so if that"s what you"re expecting, you"ll have to look elsewhere. But if you just want a small display that mounts to the Pi easily and is more affordable than the Raspberry Pi Foundation"s own 7" touchscreen, this is a great buy!

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).

This new library is a standalone library that contains the TFT driver as well as the graphics functions and fonts that were in the GFX library. This library has significant performance improvements when used with an UNO (or ATmega328 based Arduino) and MEGA.

Examples are included with the library, including graphics test programs. The example sketch TFT_Rainbow_one shows different ways of using the font support functions. This library now supports the "print" library so the formatting features of the "print" library can be used, for example to print to the TFT in Hexadecimal, for example:

To use the F_AS_T performance option the ILI9341 based display must be connected to an MEGA as follows:MEGA +5V to display pin 1 (VCC) and pin 8 (LED) UNO 0V (GND) to display pin 2 (GND)

TFT_ILI9341 library updated on 1st July 2015 to version 12, this latest version is attached here to step 8:Minor bug when rendering letter "T" in font 4 without background fixed

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.

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.

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.

With the integration of Bridgetek’s next generation EVE3 BT815/BT816 Embedded Video Engine IC, Matrix Orbital EVE3 SPI TFT"s deliver clean, crisp, full color TFT screens for interactive menus, graphing, graphics and even video.

Point of Sales Machines, Multi-function Printers, Instrumentation, Home Security Systems, Graphic touch pad – remote, dial pad, Tele/Video Conference Systems, Phones and Switchboards, Medical Appliances, Breathalyzers, Gas chromatographs, Power meter, Home appliance devices, Set-top box, Thermostats, Sprinkler system displays, GPS / Satnav, Vending Machine Control Panels, Elevator Controls, and many more....