tft lcd driver chip free sample

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.

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 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).

"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.

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 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.

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 is based on the Adafruit GFX and Adafruit driver libraries and the aim is to retain compatibility. Significant additions have been made to the library to boost the speed for the different processors (it is typically 3 to 10 times faster) and to add new features. The new graphics functions include different size proportional fonts and formatting features. There are lots of example sketches to demonstrate the different features and included functions.

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

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).

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.

i looked up 8347 and found there is are controllers with that number, and i tried the UTFT set up for the HX8347A controller with no luck, but im hoping someone with more knowledge than me can figure it out.

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).

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.

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).

Since the reference voltages are connected to all channels, many DACs may use the same reference voltage. The more DACs there are connected to a single reference voltage, the larger the required C-DAC settling time. This study simulates the settling time for different numbers of connected DACs using a 0.35-μm 5-V CMOS model. Figure 11 shows the simulated results where the settling time is measured at 99.9% of its final voltage for a full swing (0.266 V ~ 4.75 V). The settling time is 5.2 μs when 200 DACs are connected to a single reference voltage. Although a column driver IC contains several hundreds or even up to a thousand DACs, these DACs are distributed to 256 (28) reference voltages. This means that not all the DACs are connected to a single reference voltage. A typical UXGA (1600×1200) display has a pixel clock frequency of 162 MHz and a horizontal scanning time of 9.877 μs [4]. Hence, the proposed column driver is suitable for UXGA displays.

Due to the limited silicon area, the proposed LCD column driver has only four channels. The 10-bit LCD column driver with R-DAC and C-DAC was fabricated using a 0.35-μm 5-V CMOS technology. Table I shows the device sizes used in the proposed column driver, where Rtop, Rmid, Rbot, and Ri are designated in Figure 7. Figure 12 is a photograph of the die. Except for the resistor string of the R-DAC, the die area is 0.2×1.26 mm2 for four channels. Each RGB digital input code is 10-bits wide.

The Differential Nonlinearity (DNL) and Integral Nonlinearity (INL) are typically measured for a DAC. However, it is difficult to determine these two specifications for a nonlinear DAC. To demonstrate the performance of the proposed circuit, the nonlinear gamma voltages are not applied to the R-string and the resistor values of the resistor string are made equal. Since an LCD panel needs several column drivers, the uniformity of different drivers is very important. Figure 13 shows the measured transfer curves of a DAC for eight off-chip column drivers. To show the deviation between different chips, Figure 14 provides an

enlarged view of the transfer curves, where the maximum deviation is 3.5 mV from the mean. This deviation is mainly due to process variations. The approach in this study uses no error correction. Hence, the deviation can be reduced by applying an offset canceling technique to the buffer amplifier. Figures 15(a) and (b) show the DNL values for positive and negative polarities, respectively. Figures 16(a) and (b) show the INL values for positive and negative polarities, respectively. The combination of R-DACs and C-DACs creates two groups of DNL values. The maximum DNL and INL values are 3.83 and 3.84 LSB, respectively. This study uses a 1-LSB voltage of 2.44mV to calculate the INL and DNL values. The linearity, however, is less important than the deviations between off-chip drivers for LCD drivers [2].

Figure 17 shows the measured output waveforms of two neighboring channels under dot inversion for the RGB digital inputs of ‘1111111111.’ Here, the voltage levels for negative and positive polarities are 0.266 V and 4.75 V, respectively. A load resistor of 5 kΩ and a capacitor of 90 pF were used. Figure 18 shows a similar waveform for ‘0000000000’ inputs, where the corresponding voltage levels for negative and positive polarities are 2.425 V and 2.598 V, respectively. These two figures show that the settling time is within 3 μs, which is smaller than that of previously published work [2] and standard UXGA displays [5]. Table II summarizes the performance of the proposed column driver IC. The average area per channel is 0.063 mm2, which is smaller than the reported areas of fully R-DAC-based column drivers [5, 8]. These experimental results show that the proposed column driver is suitable for UXGA LCD-TV applications.

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:

In the library Font 0 (GLCD font), 2, 4, 6 and 8 are enabled. Edit the Load_fonts.h file within the library folder to enable/disable fonts to save space.

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