ESP32-P4-Knob-Touch-AMOLED-1.75

The ESP32-P4-Knob-Touch-AMOLED-1.75 is a knob display development board based on the ESP32-P4NRW32X. It combines a 1.75inch 466 × 466 capacitive touch AMOLED display, an ESP32 wireless coprocessor, a rotary knob with vibration feedback, a power management IC, a six-axis IMU, an RTC, an audio codec with dual microphones, and a TF card slot in a CNC-machined metal case. The factory firmware is built on ESP-Brookesia and provides media playback, Bluetooth audio, a USB extended display for Windows, a voice assistant, and other applications. ESP-IDF and Arduino examples are provided for secondary development.

If you are looking for:

• Coding with AI tools: Click Ask AI and select an AI tool to ask questions about this page, or choose Copy page to copy its content and paste it into an AI tool for coding assistance.
• Example code, firmware, and datasheets: See Resources
• Factory firmware: See Factory Firmware Usage
• Arduino development: See Working with Arduino
• ESP-IDF development: See Working with ESP-IDF
• Troubleshooting: See FAQ or contact Technical Support

Version Options

The four versions differ in case color and in whether a lithium battery is installed.

Model	Case Color	Lithium Battery	Package Contents
ESP32-P4-Knob-Touch-AMOLED-1.75S	Silver	3.7V 800mAh 102035 lithium battery, installed before shipment	Host ×1
ESP32-P4-Knob-Touch-AMOLED-1.75S-EN	Silver	Not included	Host ×1, anti-slip rubber ring ×1
ESP32-P4-Knob-Touch-AMOLED-1.75B	Black	3.7V 800mAh 102035 lithium battery, installed before shipment	Host ×1
ESP32-P4-Knob-Touch-AMOLED-1.75B-EN	Black	Not included	Host ×1, anti-slip rubber ring ×1

A 1GB TF card is installed in the TF card slot of every version.

ESP32-P4-Knob-Touch-AMOLED-1.75S

ESP32-P4-Knob-Touch-AMOLED-1.75S-EN

ESP32-P4-Knob-Touch-AMOLED-1.75B

ESP32-P4-Knob-Touch-AMOLED-1.75B-EN

Features

• Uses the ESP32-P4NRW32X with RISC-V 32-bit dual-core and single-core processors, 128KB HP ROM, 16KB LP ROM, 768KB HP L2MEM, 32KB LP SRAM, and 8KB TCM
• 32MB PSRAM in the chip package and 32MB NOR Flash on the board
• Onboard ESP32-D0WD-V3 wireless coprocessor for 2.4GHz Wi-Fi (802.11 b/g/n), Classic Bluetooth, and BLE 4.2, with an onboard ceramic antenna and an IPEX 1 connector
• Image and voice processing peripherals, including a JPEG codec, Pixel Processing Accelerator (PPA), Image Signal Processor (ISP), and H.264 encoder
• 1.75inch 466 × 466 AMOLED display with a MIPI-DSI interface and capacitive touch
• Rotary knob with two direction switches, and a vibration motor for haptic feedback
• ES8389 audio codec, ES7210 audio ADC, dual microphones with an echo cancellation circuit, a speaker amplifier, a speaker installed in the case, and a 3.5mm audio jack
• AXP2101 power management IC, PCF85063 RTC, QMI8658 six-axis IMU, and a TF card slot with a 1GB TF card installed
• USB Type-C port: the plug orientation selects either the ESP32-P4 USB 2.0 port or the USB-to-UART serial port
• Security features: Secure Boot, Flash Encryption, cryptographic accelerators, TRNG, Digital Signature Peripheral, and Key Management Unit; hardware access protection supports Access Permission Management and Privilege Separation
• CNC-machined metal case in silver or black

AMOLED Specifications

Parameter	Value	Parameter	Value
Display panel	AMOLED	Display size	1.75inch
Resolution	466 × 466 pixels	Display colors	16.7M
Brightness	700 cd/m²	Contrast ratio	100000:1
Interface	MIPI-DSI	Display driver IC	CO5300
Touch	Capacitive	Touch IC	CST9217

Onboard Resources

Main Board

1. ESP32-P4NRW32X: main controller with 32MB PSRAM in the package
2. ESP32-D0WD-V3: wireless coprocessor for Wi-Fi and Bluetooth, 240MHz operating frequency, with 2MB Flash
3. AXP2101: power management IC
4. PCF85063: RTC chip
5. ES7210: audio ADC, supports echo cancellation algorithms for audio capture
6. Knob direction switches: two switches triggered by knob rotation, one for each direction
7. Display connector: connects the 1.75inch AMOLED panel
8. TF card slot: a 1GB TF card is installed by default
9. Dual microphones: with an echo cancellation circuit
10. IPEX 1 connector: for an external antenna; switch to it by resoldering an onboard resistor
11. Onboard ceramic antenna: for 2.4GHz Wi-Fi (802.11 b/g/n) and Bluetooth
12. ES8389: audio codec
13. QMI8658: six-axis IMU with a 3-axis gyroscope and a 3-axis accelerometer
14. 32MB NOR Flash

Adapter Board

1. Vibration motor
2. PH1.27 14PIN SMD header
3. PH1.25 lithium battery header: for a 3.7V lithium battery
4. 3.5mm audio jack
5. PWR button
6. USB Type-C port: the plug orientation selects the ESP32-P4 USB 2.0 port or the USB-to-UART serial port
7. BOOT button: hold BOOT and power on the board again to enter download mode

USB Type-C Plug Orientation

One orientation of the USB Type-C plug connects the onboard CH343P USB-to-UART chip, which is connected to ESP32-P4 UART0 (GPIO37 TXD, GPIO38 RXD) and is used for flashing and serial logs. The other orientation connects the ESP32-P4 high-speed USB 2.0 port, which is used by USB Screen, the USB drive function in Settings, and the USB display example. Flipping the plug powers the board up again.

Internal Hardware Connections

The following connections are taken from the board definition used by the examples. The onboard I2C devices share one bus.

Display and Touch: CO5300 AMOLED and CST9217 touch (click to expand)

ESP32-P4	Signal	Description
MIPI-DSI	DSI, 1 data lane	CO5300 display data
GPIO29	LCD_RST	Display reset, active low
LDO_VO3	VDD_MIPI_DPHY	MIPI D-PHY supply, 2.5V
GPIO7	TP_SDA	Touch I2C data
GPIO8	TP_SCL	Touch I2C clock
GPIO26	TP_INT	Touch interrupt, active low
GPIO27	TP_RST	Touch reset, active low

I2C Bus: onboard I2C devices and addresses (click to expand)

The I2C bus uses GPIO7 (SDA) and GPIO8 (SCL). The addresses below are 7-bit addresses.

Device	Function	I2C Address
CST9217	Capacitive touch	0x5A
ES8389	Audio codec	0x10
ES7210	Audio ADC	0x40
AXP2101	Power management	0x34
PCF85063	RTC	0x51
QMI8658	Six-axis IMU	0x6B; the examples also probe 0x6A

Audio: ES8389, ES7210, and NS4150B amplifier (click to expand)

ESP32-P4	Signal	Description
GPIO13	I2S_MCLK	I2S master clock
GPIO12	I2S_BCLK	I2S bit clock
GPIO10	I2S_WS	I2S word select
GPIO9	I2S_DOUT	Playback data to the ES8389
GPIO11	I2S_DIN	Microphone data from the ES7210
GPIO53	PA_EN	NS4150B speaker amplifier enable on the adapter board, active high

The two microphones are connected to ES7210 MIC1 and MIC2.

Knob and Vibration Motor (click to expand)

ESP32-P4	Signal	Description
GPIO20	KNOB_CW	Clockwise direction switch, active low, one pulse per detent
GPIO21	KNOB_CCW	Counterclockwise direction switch, active low, one pulse per detent
GPIO22	MOTOR_IN1	DRV8837 IN1
GPIO23	MOTOR_IN2	DRV8837 IN2

The knob uses two independent direction switches, not a quadrature encoder. Driving IN1 high and IN2 low runs the vibration motor; driving both low stops it.

Buttons and Interrupts (click to expand)

ESP32-P4	Signal	Description
GPIO35	BOOT	BOOT button, active low
GPIO2	PWR	PWR button state through a BSS138 inverter: HIGH when pressed, LOW when released
GPIO3	RTC_INT	PCF85063 interrupt
GPIO4	IMU_INT1	QMI8658 INT1
GPIO5	IMU_INT2	QMI8658 INT2

The PWR button is also connected to the PWRON pin of the AXP2101.

TF Card: SDMMC slot 0 (click to expand)

ESP32-P4	Signal	Description
GPIO43	SD_CLK	SDMMC clock
GPIO44	SD_CMD	SDMMC command
GPIO39	SD_D0	SDMMC data 0
GPIO40	SD_D1	SDMMC data 1
GPIO41	SD_D2	SDMMC data 2
GPIO42	SD_D3	SDMMC data 3

Dimensions

Development Methods

The ESP32-P4-Knob-Touch-AMOLED-1.75 supports both the Arduino IDE and ESP-IDF. The ESP-IDF examples and the factory application use ESP-IDF v6.1; the Arduino examples use Arduino-ESP32 3.3.12.

• Arduino IDE is suitable for quickly running the peripheral examples. The repository provides the board configuration, display, audio, and wireless libraries required by the sketches.
• ESP-IDF is the Espressif IoT Development Framework. It provides project configuration, component management, and debugging tools, and is used to build the factory application.