spi tft lcd controller quotation

TFT displays are full color LCDs providing bright, vivid colors with the ability to show quick animations, complex graphics, and custom fonts with different touchscreen options. Available in industry standard sizes and resolutions. These displays come as standard, premium MVA, sunlight readable, or IPS display types with a variety of interface options including HDMI, SPI and LVDS. Our line of TFT modules include a custom PCB that support HDMI interface, audio support or HMI solutions with on-board FTDI Embedded Video Engine (EVE2).

I doubt the banding is down to the library so I am unable to help further. It may be a different driver chip and certainly some chips do accept init sequences designed for other controllers and appear to work OK. The ILI9486 does not work well with a ILI9481 driver though, see example here.

I am blocked because I have the same TFT as on the photo. I have to connect it to a pcb that use the same SPI for the display and for the touchscreen. I am using a ESP32 but I am not sure it is meaningful.

When the TFT_RST pin is defined as output and set to HIGH, the XPT2046 returns only a value equal to zero when I read it. Otherwise, it replies with values that seems OK (they change when I touch the screen).

Note: I have a friend that has the same TFT. He did not remove the diode (was not aware off this) and his TFT works just fine using exactly the same firmware and the same board.

All displays work in a similar manner. In a very basic explanation, they all have many rows and columns of pixels driven by a controller that communicates with each pixel to emit the brightness and color needed to make up the transmitted image. In some devices, the pixels are diodes that light up when current flows (PMOLEDs and AMOLEDs), and in other electronics, the pixel acts as a shutter to let some of the light from a backlight visible. In all cases, a memory array stores the image information that travels to the display through an interface.

Serial Peripheral Interface (SPI) is a synchronous serial communication interface best-suited for short distances. It was developed by Motorola for components to share data such as flash memory, sensors, Real-Time Clocks, analog-to-digital converters, and more. Because there is no protocol overhead, the transmission runs at relatively high speeds. SPI runs on one master (the side that generates the clock) with one or more slaves, usually the devices outside the central processor. One drawback of SPI is the number of pins required between devices. Each slave added to the master/slave system needs an additional chip select I/O pin on the master. SPI is a great option for small, low-resolution displays including PMOLEDs and smaller LCDs.

Philips Semiconductors invented I2C (Inter-integrated Circuit) or I-squared-C in 1982. It utilizes a multi-master, multi-slave, single-ended, serial computer bus system. Engineers developed I2C for simple peripherals on PCs, like keyboards and mice to then later apply it to displays. Like SPI, it only works for short distances within a device and uses an asynchronous serial port. What sets I2C apart from SPI is that it can support up to 1008 slaves and only requires two wires, serial clock (SCL), and serial data (SDA). Like SPI, I2C also works well with PMOLEDs and smaller LCDs. Many display systems transfer the touch sensor data through I2C.

Low-Voltage Differential Signaling (LVDS) was developed in 1994 and is a popular choice for large LCDs and peripherals in need of high bandwidth, like high-definition graphics and fast frame rates. It is a great solution because of its high speed of data transmission while using low voltage. Two wires carry the signal,  with one wire carrying the exact inverse of its companion. The electric field generated by one wire is neatly concealed by the other, creating much less interference to nearby wireless systems. At the receiver end, a circuit reads the difference (hence the "differential" in the name) in voltage between the wires. As a result, this scheme doesn’t generate noise or gets its signals scrambled by external noise. The interface consists of four, six, or eight pairs of wires, plus a pair carrying the clock and some ground wires. 24-bit color information at the transmitter end is converted to serial information, transmitted quickly over these pairs of cables, then converted back to 24-bit parallel in the receiver, resulting in an interface that is very fast to handle large displays and is very immune to interference.