3.5 inch 320x480 IPS Capacitive Touch Screen LCD Module SPI Serial ST7796U Driver for Arduino R3/Mega2560

This is for the 4" 320x480 capacitive touch display with ST7796s. I first tested out the display itself, and found the TFT_eSPI to work well. For reading the touchscreen, I only really tested position and haven't looked into gestures yet, but I found that both RAK14014-FT6336U and the Arduino-FT6336U libraries worked equally well for what I tested. The RAK library actually used up a bit more program memory, about 240 bytes more, so if your processor is small in that department, might consider that. Here are some tidbits that I needed to learn through experimentation that might help others get running quicker: 1) SPI interface to the display runs well at 80MHz. I used ESP32 DEV, so no problem. 2) On ESP32, use default SPI pins in order to use hardware driver, which is fastest. 3) On I2C interface for touchpad, use default pins for SDA and SCLK. Easiest way to check which pins these are is to print out SDA and SCLK to the serial port. 4) The FT6336U interrupt pin is mostly useful to wake up the processor while in a sleep state. During normal operation, interrupts constantly come in and cannot easily be used to determine when a touch has happened. Need to poll the TD_STATUS register to see if non-zero and not use the interrupt line in normal operation. 5) TFT_eSPI is a very inclusive library, but you will need to alter it unless you have a board and pin setup combo that matches one of the many examples. This is not documented well. I recommend taking the SetupX_Template.h file in the User_Setups folder, configure it according to the comments in the file, save it as a new filename, and then you only need to change a single line in the standard library files from that point onwards, even if this library gets updated in the future. Then you can either copy this custom name file to the User_Setup.h file and overwrite the original. Or, everytime a new library version comes out, just edit the User_Setup_Select.h file to comment out the User_Setup.h and add a line to use the new file you created. Both ways work well. But expect that you will need to do this bit of customization to the library. 6) I2C address for the touchpad is as in the FT6336U library, address 0x38. You can also find example scanner sketches online which will confirm your board's touchpad I2C address. Overall, the display is a great value - nice and bright, large, and with a capacitive touchscreen that pretty much works out of the box without calibration.

This 4.0-inch display is a fantastic option, especially if you're looking for something larger than the usual 2.5" to 3.5" screens. The 320x480 resolution provides sharp visuals, and the capacitive touch (FT6336U) is highly responsive and accurate with no calibration needed. Key Highlights: ✅ 4-wire SPI for the ST7796 display and I2C for the FT6336U capacitive touch—a great setup that ensures fast refresh rates and smooth performance. ✅ Use TFT-eSPI library support for video, though some customization is needed. ✅ FT6336U library for touch, which works flawlessly. ✅ 14-line ribbon connector with labeled pins—a fantastic inclusion! My dev board had all the display pins lined up but not the touch, so I had to use the ribbon to connect the touch functionality while still mounting the display. The fact that they included the ribbon cable is a huge plus. ✅ SD card slot (though I haven't tested it). If you're looking for the best 4-wire SPI screen with great refresh rates, this is the one to get. Highly recommended for anyone needing a solid display. Comes with documentation (better than most), but is still confusing. Just follow the advice of the reviews. 4.5 stars (rounded up to 5). Not perfect, but I haven't seen any better SPI displays.

Using this with an Arduino Mega 2560. First off, it just works. The display is top notch with black levels nearing OLED levels. The colors are bright and the images are sharp. The documentation is superb. The provided character font is not great. If I could figure out how to load a better font, it would get 5 stars. There is some text in the documentation suggesting it can be done, but I have not found any details on how that is accomplished. For static text, I just use a bitmap with a better font. My perspective is one of an EE with over 50 years of hardware and system software design experience.

The display looks fully featured, but the included code is old, obsolete, and does not work I will spend a few more hours trying to get it to work, but will likely send it back

I haven't tested the touch screen but who cares about that, beautiful display it booted right out of the box with e_spi driver for rp2040. I've included a screenshot of my settings hopefully someone can be helped. Because of its size and resolution it has slight dimness between pixels. I love this display and I hope it lasts. I got this display because Adafruit has discontinued their 320x480 display in this size range. Thanks Hosyond!

Decent quality IPS screen. Capacitive touch is okay. This display has a different pixel setup than most other IL9341 LCD units (inverted, check pixel order too) and the screens are mounted kinda poorly so they don't sit flush on the board. Not sure I'd buy these over other similar LCD units again.

Arduino MEGA works with Adafruit_ST7796S_kbv Teensy 4.1 works with ILI9488_t3 Touch works with FT6336U (FT6336U CPT Controller). Touch did not work with RAK14014_FT6336U as another review suggests. That library is missing the definition of reset pin. Maybe Needs to use the main board reset pin. That said, I did not spend too much time trying to debug it. I am only using the touch for pressing buttons, so I do not know how it works for gestures. For simple touches, it works way better than a resistive touch. No debouncing needed and very clean touch coordinates. It is an SPI screen, so drawing time is noticeable, but it is significantly faster for Teensy 4.x. Documentation: Good for pin and mechanical descriptions. Manufacturer libraries: don't try...

Functions on a part time basis. The LCD display and touch sense work occasionally. Not many drivers available for the FT6336U sensing chip. Frequently receive I2C errors and device freezes. Not recommended. Returning.

Using it with Mega2560. The display is crisp and clear. The website for this product has some of the best documentation I've seen. Physical drawings, libraries, example programs, connection diagrams, technical specs, etc. Very happy with it but a couple of little issues to get it going... Issue #1: the demo programs declare either my_lcd or mylcd. Either spelling is fine, but they try to use both in the same sketch causing errors at compile. Edit the demo programs so you have either my_lcd or mylcd, not both. Issue #2 In each demo there are lines similar to this at the beginning. //LCDWIKI_SPI mylcd(130,130,10,9,8,A3); . You need to "uncomment" (remove the two slashes at the beginning of the line) ONE of those lines. For the 4.0 inch, I used the line where it says the module is not known and edited it to LCDWIKI_SPI mylcd(320,480,10,9,8,A3); Issue #3 The line in issue #2 assigns the LED control to pin A3 (assuming you are setting up for a Mega2560) but the library needs a uint_8 (8 bit unsigned integer) and does not understand what A3 means. If you follow the wiring connections in the file 4.0inch_SPI_MSP4030_MSP4031_UNO_Mega2560_Demo_Instructions_EN.pdf that comes with their demo package the LED control is connected to pin 5, so edit the line to read LCDWIKI_SPI mylcd(320,480,10,9,8,5); and everything works great. Issue #4 The Demo Instructions list Mega2560 pins A4 and A5 for the touch screen I2C connections, These are pin numbers for Arduino Uno and won't work on the 2560. Connect CTP_SCL to pin 21 and CTP_SDA to pin 20 on the Mega2560

Using this on a teensy 4.1. Had a few problems at first: ST7796 driver didn't work, so used Arduino_ILI9341 - works fine! Runs up to 110mhz spi on my teensy with good clean soldering and short cables. FT6336U didn't work at first - bad driver code from github (aselectroworks/Arduino-FT6336U - don't use this doesn't work - has a 10ms delay in the readbyte code e.t.c. lol), so cobbled together my own from github "strange-v/FT6X36" driver. Had trouble with that as well - had to delay 300ms on power up before using the FT - else it would't init at all. Also had problems with the FT cutting out while SPI display was updating - All these problems were caused because my CPT reset pin wasn't being used - did not connect it and so it was floating and SPI triggered it - just tie it to VCC if not using it. You can also tie the LCD reset to GND and CS to VCC with a 4.7k resistor if your only using 1 display. Now everything is working great - it's a great display with a nice slick and easy CPT touch interface! With LVGL I get 30fps no problem without using the fast t4 code library.

work as expected

Was going crazy trying to figure out why I couldn’t get this thing going. This thing has the newer ILI19488 chipset, eSPI_TFT has a profile for it. Follow the pin mapping in the profile preset, it works. To the seller: Seriously, update the listing, you wasted too much of my time. Screen looks great, documentation exists, the touchscreen seems to be hard to deal with, though i may have gotten a bad unit