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+--- Thread: B4 ESP32-S3 IO pins define (/showthread.php?tid=8913)
B4 ESP32-S3 IO pins define - admin - 01-14-2026
IIC Bus:
SDA:GPIO8
SCL:GPIO18
PCF8574: i2c address:0x24
PCF8574->P0 (digital input-1)
PCF8574->P1 (digital input-2)
PCF8574->P2 (digital input-3)
PCF8574->P3 (digital input-4)
PCF8574->P4 (relay1)
PCF8574->P5 (relay2)
PCF8574->P6 (relay3)
PCF8574->P7 (relay4)
24C02 EPROM i2c address: 0x50
DS3231 RTC i2c address: 0x68
SSD1306 display: i2c address:0x3c
ADS1115 (4CH ADC): i2c address:0x48
Analog input (A1: DC 0-5v)
Analog input (A2: DC 0-5v)
Analog input (A3: DC 4-20mA)
Analog input (A4: DC 4-20mA)
-----------------
1-wire GPIOs (with pull-up resistance on PCB):
1-wire-1:GPIO47
1-wire-2:GPIO48
1-wire-3:GPIO17
1-wire-4:GPIO40
-----------------
free GPIOs (without pull-up resistance on PCB):
GPIO13
GPIO14
GPIO21
-----------------
Ethernet (W5500) I/O define:
clk_pin: GPIO1
mosi_pin: GPIO2
miso_pin: GPIO41
cs_pin: GPIO42
interrupt_pin: GPIO43
reset_pin: GPIO44
--------------------
RS485:
RXD:GPIO39
TXD:GPIO38
Tuya module:
RXD:GPIO16
TXD:GPIO15
Tuya network button: Tuya module's P28
Tuya network LED: Tuya module's P16
--------------------
SD Card:
SPI-MOSI:GPIO10
SPI-SCK:GPIO11
SPI-MISO:GPIO12
SPI-CS:GPIO9
SPI-CD:GPIO5