LCD wiki E32R28T 2.8inch ESP32-32E Display Module

Lethathamo la lisebelisoa le kenyelletsa sample programs, software libraries, product specifications, structure diagrams, datasheets, schematics, user manuals, and tool software.
Karolo ena e fana ka tlhalosoview of the hardware resources available on the module.

Explains the schematic diagram of the display module in detail.
Provides precautions to be taken while using the display module.

Tlhaloso ea Mohloli

Lenane la lisebelisoa le bontšitsoe setšoantšong se latelang:

Directory	Tlhaloso ea Litaba
1-Mohlala	Likarolo tsa sample khoutu ea lenaneo, laebrari ea software ea motho oa boraro eo sample lenaneo le itšetlehile ka, phetolo ea laeborari ea motho oa boraro file, tokomane ea litaelo tsa ho seta tikoloho ea software, le sample program instruction tokomane.
2-Tlhaloso	Bontša tlhahiso ea sehlahisoa sa module, tlhahiso ea skrine ea LCD le khoutu ea ho qala ea IC ea mokhanni oa LCD.
3-Sebopeho_Sets'oants'o	Bontša boholo ba sehlahisoa sa module le litšoantšo tsa 3D tsa sehlahisoa
4-Leqephe la lintlha	LCD display driver ILI9341 data book, resistance driver XPT2046 data book, ESP32 master data book and hardware design guide document, USB to Serial IC(CH340C) buka ya data, audio amplifier chip FM8002E data book, 5V to 3.3V regulator data book and battery charge management Chip TP4054 data sheet.
5-Leano	Product hardware schematic, ESP32-WROOM-32E module IO resource allocation table, schematic, and PCB component package
6-User_Manual	Litokomane tsa basebelisi ba sehlahisoa
7-Tool_software	WIFI le Bluetooth test APP le lisebelisoa tsa ho lokisa liphoso, USB to serial port driver, ESP32 Flash download tool software, software ea ho nka litlhaku, software ea ho nka litšoantšo, software ea JPG image processing. and serial port debugging tools.
8-Kapele_Qala	Need to burn the bin file, flash the download tool, and use the instructions.

Litaelo tsa Software

Mehato ea nts'etsopele ea software ea ho bonts'a ke e latelang:

A. Haha tikoloho ea ntlafatso ea software ea ESP32.

B. If necessary, import third-party software libraries as a basis for development;
C. Open the software project to be debugged, or you can also create a new software project.

D. power on the display module, compile and download the debugging program, and then check the software running effect.
E. The software effect does not reach the expected, continue to modify the program code, and then compile and download, until the effect reaches the expected.
For details about the preceding steps, see the documentation in the 1 Demo directory.

Litaelo tsa Hardware

Fetileview of the module’s hardware resources is displayed

Lisebelisoa tsa li-hardware tsa module li bonts'oa litšoantšong tse peli tse latelang:

Lisebelisoa tsa hardware li hlalosoa ka tsela e latelang:

LCD

The LCD display size is 2.8 inches, the driver IC is ILI9341, and the resolution is 24 0x 32 0. The ESP32 is connected using a 4-wire SPI communication interface.
A. Introduction to ILI9341 controller The ILI9341 controller supports a maximum resolution of 240*320 and a 172800-byte GRAM. It also supports 8-bit, 9-bit, 16-bit, and 18-bit parallel port data buses. It also supports 3-wire and 4-wire SPI serial ports. Since parallel control requires a large number of I/O ports, the most common one is SPI serial port control. The ILI9341 also supports 65K, 262K RGB color display, display color is very rich, while supporting rotating display and scroll display and video playback, and displaying in a variety of ways.

Molaoli oa ILI9341 o sebelisa 16bit (RGB565) ho laola ponts'o ea pixel, kahoo e ka bonts'a mebala ea 65K ka pixel. Boemo ba aterese ea pixel bo etsoa ka tatellano ea mela le likholomo, 'me tsela e ntseng e eketseha le e fokotsehang e khethoa ke mokhoa oa ho hlahloba. Mokhoa oa ho bonts'a ILI9341 o etsoa ka ho beha aterese ebe o beha boleng ba 'mala.
B. Kenyelletso ea protocol ea puisano ea SPI

Nako ea ho ngola ea bese ea SPI ea terata e 4 e bonts'oa setšoantšong se latelang:

CSX ke khetho ea chip ea makhoba, 'me chip e tla lumelloa feela ha CSX e le maemong a tlase a matla.
D/CX ke phini ea taolo ea data/taelo ea chip. Ha DCX e ngola litaelo maemong a tlase, data e ngotsoe maemong a holimo

SCL is the SPI bus clock, with each rising edge transmitting 1 bit of data.
SDA ke data e fetisoang ke SPI, e fetisang likotoana tse 8 tsa data hang. Sebopeho sa data se bontšoa setšoantšong se latelang:

Phahamisa hanyane pele, fetisetsa pele.
Bakeng sa puisano ea SPI, data e na le nako ea phetisetso, e kopantsoeng le karolo ea oache ea nako ea nnete (CPHA) le polarity ea oache (CPOL):
Boemo ba CPOL bo lekanya boemo ba boemo bo sa sebetseng ba oache ea serial synchronous, ka CPOL=0, e bonts'ang boemo bo tlase. Protocol ea phetisetso ea lipara tsa CPOL
The discussion did not have much influence.
Bophahamo ba CPHA bo etsa qeto ea hore na oache ea serial synchronous e bokella data moeling oa pele kapa oa bobeli oa ho tlola,
Ha CPHL=0, etsa pokello ea lintlha karolong ea pele ea phetoho;
Motsoako oa mefuta ena e 'meli ea mekhoa e mene ea puisano ea SPI, le SPI0 e sebelisoa hangata Chaena, moo CPHL=0 le CPOL=0

ESP32 WROOM 32E M odule

This module has a built-in ESP32-DOWD-V3 chip, an Xtensa dual-core 32-bit LX6 microprocessor, and supports clock rates up to 240MHz. It has 448KB ROM, 520KB SRAM, 16KB RTC SRAM, and 4MB QSPI Flash. 2.4GHz WIFI,
Bluetooth V4.2 and Bluetooth Low Power modules are supported. External 26 GPIOs, support SD card, UART, SPI, SDIO, I2C, LED PWM, motor PWM, I2S, IR, pulse counter, GPIO, capacitive touch sensor, ADC, DAC, TWAI and other peripherals.

Khadi ea MicroSD Slot

Ho sebelisa mokhoa oa puisano oa SPI le khokahano ea ESP32, tšehetso ea likarete tsa MicroSD tsa bokhoni bo fapaneng.

RGB Three color Light

Red, green, and blue LED lights can be used to indicate the running status of the program.

Serial Port

Mojule oa kantle oa serial port o sebelisoa bakeng sa puisano ea serial port.

USB to Serial Port and One-click Download Circuit

Sesebelisoa sa mantlha ke CH340C, pheletso e 'ngoe e hokahane le komporo ea USB, pheletso e' ngoe e hokahane le koung ea serial ea ESP32, e le ho fihlela USB ho TTL serial port.
In addition, a one-click download circuit is also attached, so that is, when downloading the program, it can automatically enter the download mode, without the need to touch the external.

Sehokelo sa Battery

Two-pin interface, one for the positive electrode, one for the negative electrode, to access the battery power supply and charging.

Battery Charge and Discharge Management Circuit

The core device is TP4054, this circuit can control the battery charging current, the battery is safely charged to saturation state, but can also safely control the battery discharge.

BOOT Key

Kamora hore mochini oa ponts'o o buloe, ho tobetsa ho tla theola IO0. Haeba motsotso oo mojule o buloang kapa ESP32 e setiloe bocha, ho theola IO0 ho tla kenya mokhoa oa ho jarolla. Linyeoe tse ling li ka sebelisoa e le likonopo tse tloaelehileng.

Mofuta oa C-C

The main power supply interface and program download interface of the display module. Connect the USB to a serial port and a one-click download circuit, can be used for power supply, download and serial communication.

5V ho isa ho 3.3V Voltage Regulator Circuit

The core device is the ME6217C33M5G LDO regulator.

Voltage regulator circuit supports 2A V~6.5V wide voltage input, a 3.3V stable voltage, 'me boholo ba tlhahiso ea hona joale ke 800mA, e ka kopanang ka botlalo le voltage le litlhoko tsa hajoale tsa mojule oa ponts'o.

RESETSA Senotlolo

Kamora hore mojule oa ponts'o o buloe, ho tobetsa ho tla hula pinana ea ho seta ea ESP32 fatše (boemo ba kamehla bo hula), e le ho fihlela ts'ebetso ea ho seta bocha.

Resistive Touch Screen Control Circuit

Sesebelisoa sa mantlha ke XPT2046, se buisanang le ESP32 ka SPI.
Potoloho ena ke borokho bo pakeng tsa "resissive touch screen" le master ESP32, ea ikarabellang bakeng sa ho fetisetsa lintlha tse skrineng sa ho ama ho mong'a ESP32, e le ho fumana lihokahanyo tsa ntlha ea ho ama.

Atolosa Pin

An input IO port, GND, and 3.3V pin that are not used on the ESP32 module are led out for peripheral use.

Backlight control circuit

The core device is a BSS138 field-effect tube.
One end of this circuit is connected to the backlight control pin on the ESP32 master, and the other end is connected to the negative pole of the LCD screen backlight LED lamp.
Backlight control pin pull up, back light, otherwise off.

Sebuela-hole

Li-terminals tsa wiring li tlameha ho hokahanngoa ka holimo. E sebelisoa ho fihlella libuela-hōle tsa monokotsoai le libuela-hole.

Matla a molumo amppotoloho ea lifier

Sesebelisoa sa mantlha ke molumo oa FM8002E ampsetsiba sa IC.
One end of this circuit is connected to the ESP32 audio DAC value output pin and the other end is connected to the horn interface.
The function of this circuit is to drive a small power horn or speaker to sound. For 5V power supply, the maximum drive power is 1.5W (load 8 ohms) or 2W (load 4 ohms).

SPI peripheral interface

4-terata tshekaletseng segokanyimmediamentsi sa sebolokigolo. Etella pele phini ea khetho ea chip e sa sebelisoeng le phini ea sebopeho sa SPI e sebelisoang ke karete ea MicroSD, e ka sebelisoang bakeng sa lisebelisoa tsa kantle tsa SPI kapa likou tse tloaelehileng tsa IO.

Detailed explanation of the schematic diagram of the display module

Type C interface circuit

Potolohong ena, D1 ke Schottky diode, e sebelisetsoang ho thibela hona joale ho khutlela morao. D2 ho D4 ke li-diode tsa ts'ireletso ea electrostatic surge ho thibela mojule oa ponts'o hore o senyehe ka lebaka la matla a mangata.tage or short circuit. R1 is the pull-down resistance. USB1 is a Type-C bus. The display module connects to Type C power supply, downloads programs, and communicates through the USB 1. Where +5V and GND are positive power voltage and ground signals USB_D and USB_D+ are differential USB signals, which are transmitted to the onboard USB to serial circuit.

5V ho isa ho 3.3V voltage regulator potoloho

Potolohong ena, C16 ~ C19 ke "bypass filter capacitor", e sebelisetsoang ho boloka botsitso ba matla a ho kenya letsoho.tage le tlhahiso voltage. The U1 is a 5V to 3.3V LDO with the model number ME6217C33M5G. Because most of the circuits on the display module need a 3.3V power supply, and the power input of the Type Cinterface is basically 5V, so a voltagE regulator e fetola potoloho ea hlokahala.

Resistive touch screen control circuit

Potolohong ena, C25 le C27 ke li-bypass filter capacitors, tse sebelisetsoang ho boloka matla a ho kenya letsoho.tage stability. R22 is a pull-up resistor used to maintain the default pin state as high. U4 is the XPT2046 control IC, The function of this IC is to obtain the coordinate voltage value of the touch point of the resistance touch screen through X+, X –, Y+, and Y four pins, and then through ADC conversion, the ADC value is transmitted to the ESP32 master. The ESP32 master then converts the ADC value to the pixel coordinate value of the display. The PEN pin is a touch interrupt pin, and the input level is low when a touch event occurs.

USB to serial port and one-click download circuit

Potolohong ena, U3 ke CH340C USB-to-serial IC, e sa hlokeng oscillator ea kantle ea kristale ho tsamaisa moralo oa potoloho. C6 ke "bypass filter capacitor" e sebelisoang ho boloka matla a ho kenya letsohotage stability. Q1 and Q2 are NPN-type triodes, and R6 and R7 are triode base limiting current resistors. The function of this circuit is to realize to USB-to-serial port and a click download function. The USB signal is input and output through UD+ and UD pins, and is transmitted to the ESP32 master through RXD and TXD pins after conversion. One-click download circuit principle:

A. Lithakhisa tsa RST le DTR tsa CH340C li hlahisa boemo bo phahameng ka ho sa feleng. Ka nako ena, li-triode tsa Q1 le Q2 ha li so bone, 'me lithakhisa tsa IO0 le lithapo tsa reset tsa taolo e kholo ea ESP32 li huleloa holimo.
B. Lithapo tsa RST le DTR tsa CH340C tse hlahisang maemo a tlase, ka nako ena, Q1 le Q2 triode li ntse li sa sebetse, 'me lithapo tsa IO0 le li-reset tsa taolo e kholo ea ESP32 li ntse li huleloa ho ea holimo.
C. The RST pin of CH340C remains unchanged, and the DTR pin outputs a high level. At this time, Q1 is still cut off, Q2 is on, the IO0 pin of the ESP32 master is still pulled up, the reset pin is pulled down, and the ESP32 enters the reset state.

D. CH340C's RST pin e hlahisa boemo bo phahameng, pini ea DTR e hlahisa boemo bo tlase, ka nako ena Q1 e buletsoe, Q2 e tima, pini ea ho tsosolosa ea ESP32 e ke ke ea phahama hang-hang hobane capacitor e hokahaneng e qosoa, ESP32 e ntse e le teng. boemong ba ho tsosolosa, 'me pin ea IO0 hang-hang e huloa fatše, ka nako ena e tla kenya mokhoa oa ho jarolla.

Matla a molumo amppotoloho ea lifier

In this circuit, R23, C7, C8, and C9 constitute the RC filter circuit, and R10 and R13 are the gain-adjusting resistors of the operational ampmoqhobi. Ha boleng ba ho hanyetsa ba R13 bo sa fetohe, boleng bo fokolang ba ho hanyetsa ba R10, bo boholo ba molumo oa sebui sa ka ntle. C10 le C11 ke li-input coupling capacitors. R11 ke sehanyetsi sa ho hula. JP1 ke lenaka / boema-kepe ba sebui. U5 ke matla a molumo oa FM8002E ampsetsiba sa IC. Kamora ho kenngoa ke AUDIO_IN, lets'oao la audio la DAC le amplified by the FM8002E gain and output to the speaker/speaker by the VO1 and VO2 pins. SHUTDOWN is the enable pin for FM8002E. The low level is enabled. By default, the high level is enabled.

ESP32 WROOM 32E main control circuit

In this circuit, C4 and C5 are bypass filter capacitors, and U2 are ESP32 WROOM 32E modules. For details about the internal circuit of this module, please refer to the official documentation.

Key reset potoloho

Potolohong ena, KEY1 ke senotlolo, R4 ke mohanyetsi oa ho hula, 'me C3 ke capacitor ea ho lieha. Hlophisa molao-motheo:

A. After powering on, C3 charges. At this time, C3 is equivalent to a short circuit, the RESET pin is grounded, and ESP32 enters the reset state.
B. Ha C3 e lefisoa, C3 e lekana le potoloho e bulehileng, phini ea RESET e huloa, ho tsosolosa ESP32 ho felile, 'me ESP32 e kena boemong bo tloaelehileng ba ho sebetsa.

C. Ha KEY1 e hatelloa, phini ea RESET e thehiloe, ESP32 e kena boemong ba ho tsosolosa, 'me C3 e lokolloa ka KEY1.
D. Ha KEY1 e lokolloa, C3 e tla lefisoa. Ka nako ena, C3 e lekana le potoloho e khuts'oane, phini ea RESET e thehiloe, ESP32 e ntse e le boemong ba RESET. Ka mor'a hore C3 e lefelloe, pinana ea ho tsosolosa e huloa, ESP32 e tsosolosoa 'me e kena boemong bo tloaelehileng ba ho sebetsa.

Haeba RESET e sa atlehe, boleng ba mamello ea C3 bo ka eketsoa ka nepo ho liehisa pini ea reset ka nako e tlase.

Interface circuit of the serial module

Potolohong ena, P2 ke setulo sa 4P 1.25mm, R29 le R30 ke li-resistors tsa impedance, 'me Q5 ke tube e sebetsang tšimong e laolang matla a ho kenya letsoho a 5V.

R31 is a pulldown resistor. Connect RXD0 and TXD0 to serial pins, and supply power to the other two pins. This port is connected to the same serial port as the onboard USB-to-serial port module.

EX pand IO and peripheral interface circuits

In this circuit, P3 a nd P4 are 4P 1.25mm pitch seats. SPI_CLK, SPI_MISO, and SPI_MOSI pins are shared with the MicroSD card SPI pins. Pins SPI_CS, IO35 are not used by on board devices, so they are led out to connect SPI, and can also be used for ordinary IO. Things to watch out for:

A. IO35 can only be input pins.

Tefo ea betri le potoloho ea taolo ea ho tsoa

In this circuit, C20, C21, C22, and C23 are bypass filter capacitors. U6 is the TP4054 battery charge management IC. R27 regulates the battery charging current. JP2 is a 2P 1.25mm pitch seat, connected to a battery. Q3 is a P-channel FET. R28 is the Q3 grid pull-down resistor. TP4054 charges the battery through the BAT pin; the smaller the R27 resistance, the larger the charging current, with a maximum is 500mA. Q3 and R28 together constitute the battery discharge circuit, When there is no power supply through the Type C interface, the +5V voltage is 0, then the Q3 gate is pulled down to a low level, the drain and the source are on, and the battery supplies power to the entire display module. When powered through the Type C interface, the +5V voltage ke 5V, ebe heke ea Q3 e phahame ka 5V, drainage le mohloli li khaotsoe, 'me phepelo ea betri e sitisoa.

1 8P LCD panel wire welding interface

Potolohong ena, C24 ke "bypass filter capacitor", 'me QD1 ke 48P 0.8mm pitch liquid crystal screen welding interface. QD1 e na le pini ea lets'oao la "touch touch screen", LCD screen voltage pin, phini ea puisano ea SPI, phini ea taolo le phini ea potoloho ea backlight. ESP32 e sebelisa lithakhisa tsena ho laola LCD le sekirini sa ho ama.

Download the key circuit

In this circuit, KEY2 is the key and R5 is the pull up resistor. IO0 is high by default and low when KEY2 is pressed. Press and hold KEY2, power on or reset, and the ESP32 will enter download mode. In other cases, KEY2 can be used as a normal key.

Potoloho ea matla a betri

Potolohong ena, R2 le R3 ke karolo e itseng ea voltage resistors, le C1 le C2 ke bypass filter capacitor. Matla a betri voltagKenyelletso ea lets'oao la e BAT + e feta ka har'a mohanyetsi oa karohano. BAT_ADC ke moqolotage value at both ends of R3, which is transmitted to the ESP32 master through the input pin and then converted by ADC to finally obtain the battery voltage bohlokoa. Molumotage divider e sebelisoa hobane ESP32 ADC e fetolela boholo ba 3.3V, athe betri saturation vol.tage ke 4.2V, e tsoileng tseleng. Moqtage atisang ka 2 ke matla a sebele a betritage.

LCD backlight control circuit

Potolohong ena, R24 ke khanyetso ea debugging mme e bolokiloe ka nakoana. Q4 ke N-channel field effect tube, R25 ke Q4 grid drop-down resistor, 'me R26 ke sehanyetsi sa morao-rao se thibelang khanya. Lebone la LCD le khanyang la LED lamp e boemong bo ts'oanang, palo e ntle e kopantsoe le 3.3V, 'me palo e mpe e hokahane le drain ea Q4. Ha phini ea taolo LCD_BL e hlahisa molumo o phahamengtage, the drain and source poles of Q4 are switched on. At this time, the negative pole of the LCD backlight is grounded, and the backlight LED lamp e buletswe mme e ntsha kganya.
When the control pin LCD_BL outputs a low voltage, mokelikeli le mohloli oa Q4 li khaotsoe, 'me leseli le ka morao la skrine la LCD le emisitsoe, le lebone le ka morao la LED l.amp ha e butsoe. Ka kamehla, lebone la LCD le tima.

Ho fokotsa khanyetso ea R26 ho ka eketsa khanya e phahameng ea lebone la morao.
In addition, the LCD_BL pin can input a PWM signal to adjust the LCD backlight.

RGB ea mebala e meraro ea ho laola leseli

Potolohong ena, LED2 ke RGB e mebala e meraro lamp, le R14~R16 ke l e mebala e meraroamp current limiting resistor.
LED2 contains red, green, and blue LED lights, which are common anode connections.

IO16, IO17 and IO22 are three control pins, which light up LED lights at low level and extinguish the LED lights at high level.

MicroSD karete slot segokanyimmediamentsi sa sebolokigolo

Potolohong ena, SD_CARD1 ke sekotjana sa karete ea MicroSD. R17 ho isa ho R21 ke lihanyetsi tse hulelang holimo bakeng sa phini ka 'ngoe. C26 ke "bypass filter capacitor". Potoloho ena ea sehokelo e sebelisa mokhoa oa puisano oa SPI. E ts'ehetsa polokelo e potlakileng ea likarete tsa MicroSD.
Hlokomela hore sebopeho sena se arolelana bese ea SPI le SPI peripheral interface.

Litlhokomelo bakeng sa tšebeliso ea mojule oa ponts'o

The display module is charged with the battery, the external speaker plays the audio, and the display screen is also working; at this time, the total current may exceed 500mA. In this case, you need to pay attention to the maximum current supported by the Type C cable and the maximum current supported by the power supply interface to avoid an insufficient power supply.

Nakong ea ts'ebeliso, u se ke oa ama molumo oa LDOtage regulator le taolo ea tefiso ea betri IC ka matsoho a hau ho qoba ho chesoa ke mocheso o phahameng.
Ha o hokela boema-kepe ba IO, ela hloko tšebeliso ea IO ho qoba ho hokela hampe mme tlhaloso ea khoutu ea lenaneo ha e tsamaellane.
Sebelisa sehlahisoa ka mokhoa o sireletsehileng le ka mokhoa o utloahalang.

LBH

P: Ke fumana sampmananeo le lilaebrari tsa software?
- A: Likarolo tsa sample programs and libraries can be found in the 1-_Demo directory of the resource description.
P: Ke lisebelisoa life tse kenyellelitsoeng ho software ea sesebelisoa?
- A: The tool software includes WIFI and Bluetooth test APP, debugging tools, USB to serial port driver, ESP32 Flash download tool software, character take-up software, image take-up software, JPG image processing software, and serial port debugging tools.

Litokomane / Lisebelisoa

Tlhaloso: LCD wiki E32R28T 2.8inch ESP32-32E Tlhaloso: [pdf] Bukana ea Mosebelisi
E32R28T, E32N28T, E32R28T 2.8inch ESP32-32E Display Module, E32R28T, 2.8inch ESP32-32E Display Module, ESP32-32E Pontšo ea Mojule, Mojule oa Pontšo, Mojule

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Bukana ea Mosebelisi

Tlhaloso: LCD wiki E32R28T 2.8inch ESP32-32E Tlhaloso:

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