FireBeetle ESP32 IoT Microcontroller (DFR0478)

Low-power IoT board (29×58 mm) with ESP32 dual-core Tensilica LX6 at 240 MHz, 520 KB SRAM, 16 MB flash, 802.11b/g/n Wi-Fi, Bluetooth 4.2, and a deep-sleep current of 10 µA. Exposes 10 digital and 5 analog pins, I2C, SPI, UART, I2S, and a microSD slot; operates from 3.3–5 V.

Logical pinout · physical placement not verified

IO3RXDD0
Arduino D0 / serial RX; connects to ESP32 IO3
Type · GPIO, UART
IO1TXDD1
Arduino D1 / serial TX; connects to ESP32 IO1
Type · GPIO, UART
IO25D2
GPIO digital I/O and PWM output; connects to ESP32 IO25
Type · GPIO
IO26D3
GPIO digital I/O and PWM output; connects to ESP32 IO26
Type · GPIO
IO27D4
GPIO digital I/O and PWM output; connects to ESP32 IO27
Type · GPIO
IO9D5
GPIO digital I/O and PWM output; connects to ESP32 IO9
Type · GPIO
IO10D6
GPIO digital I/O and PWM output; connects to ESP32 IO10
Type · GPIO
IO13D7
GPIO digital I/O and PWM output; connects to ESP32 IO13
Type · GPIO
IO5D8
GPIO digital I/O and PWM output; connects to ESP32 IO5
Type · GPIO
IO2D9
GPIO digital I/O and PWM output; connects to ESP32 IO2
Type · GPIO
IO36A0
Arduino A0 analogue input; connects to ESP32 IO36
Type · GPIO, Analog
IO39A1
Arduino A1 analogue input; connects to ESP32 IO39
Type · GPIO, Analog
IO34A2
Arduino A2 analogue input; connects to ESP32 IO34
Type · GPIO, Analog
IO35A3
Arduino A3 analogue input; connects to ESP32 IO35
Type · GPIO, Analog
IO15A4
Arduino A4 analogue input; connects to ESP32 IO15
Type · GPIO, Analog
SCK
SPI clock pin; connects to ESP32 IO18
Type · SPI
MOSI
SPI MOSI data wire; connects to ESP32 IO23
Type · SPI
MISO
SPI MISO data wire; connects to ESP32 IO19
Type · SPI
SDA
I2C data wire; connects to ESP32 IO21
Type · I2C
SCL
I2C clock pin; connects to ESP32 IO22
Type · I2C
BCLK
I2S clock pin; connects to ESP32 IO14
Type · Unknown
MCLK
I2S master clock pin; connects to ESP32 IO12
Type · Unknown
DO
I2S data output wire; connects to ESP32 IO4
Type · Unknown
DI
I2S data input wire; connects to ESP32 IO16
Type · Unknown
LRCK
I2S LRCK data wire; connects to ESP32 IO17
Type · Unknown
CLK
Clock pin to ESP32 IO6
Type · Unknown
SD0
SD0 port to ESP32 IO7
Type · Unknown
SD1
SD1 port to ESP32 IO8
Type · Unknown
CMD
CMD port to ESP32 IO11
Type · Unknown
IO0
Digital interface; connects to ESP32 IO0
Type · GPIO
RST
Low-level reset port
Type · Control
GND
Power line ground
Type · Ground
3V3
3.3 V output; datasheet states it can provide up to 600 mA current out
Type · PowerVoltage · 3.3V output, up to 600mA
VCC
Vi/Vo rail; 5 V when powered by USB, 3.7 V when powered by lithium battery
Type · PowerVoltage · 5V on USB or 3.7V on lithium battery
AREF
Input voltage reference; connected to NC on this board
Type · Analog
NC
Not connected
Type · Control

Pin	Type	Function	Voltage
IO3RXDD0	GPIO, UART	Arduino D0 / serial RX; connects to ESP32 IO3
IO1TXDD1	GPIO, UART	Arduino D1 / serial TX; connects to ESP32 IO1
IO25D2	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO25
IO26D3	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO26
IO27D4	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO27
IO9D5	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO9
IO10D6	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO10
IO13D7	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO13
IO5D8	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO5
IO2D9	GPIO	GPIO digital I/O and PWM output; connects to ESP32 IO2
IO36A0	GPIO, Analog	Arduino A0 analogue input; connects to ESP32 IO36
IO39A1	GPIO, Analog	Arduino A1 analogue input; connects to ESP32 IO39
IO34A2	GPIO, Analog	Arduino A2 analogue input; connects to ESP32 IO34
IO35A3	GPIO, Analog	Arduino A3 analogue input; connects to ESP32 IO35
IO15A4	GPIO, Analog	Arduino A4 analogue input; connects to ESP32 IO15
SCK	SPI	SPI clock pin; connects to ESP32 IO18
MOSI	SPI	SPI MOSI data wire; connects to ESP32 IO23
MISO	SPI	SPI MISO data wire; connects to ESP32 IO19
SDA	I2C	I2C data wire; connects to ESP32 IO21
SCL	I2C	I2C clock pin; connects to ESP32 IO22
BCLK	Unknown	I2S clock pin; connects to ESP32 IO14
MCLK	Unknown	I2S master clock pin; connects to ESP32 IO12
DO	Unknown	I2S data output wire; connects to ESP32 IO4
DI	Unknown	I2S data input wire; connects to ESP32 IO16
LRCK	Unknown	I2S LRCK data wire; connects to ESP32 IO17
CLK	Unknown	Clock pin to ESP32 IO6
SD0	Unknown	SD0 port to ESP32 IO7
SD1	Unknown	SD1 port to ESP32 IO8
CMD	Unknown	CMD port to ESP32 IO11
IO0	GPIO	Digital interface; connects to ESP32 IO0
RST	Control	Low-level reset port
GND	Ground	Power line ground
3V3	Power	3.3 V output; datasheet states it can provide up to 600 mA current out	3.3V output, up to 600mA
VCC	Power	Vi/Vo rail; 5 V when powered by USB, 3.7 V when powered by lithium battery	5V on USB or 3.7V on lithium battery
AREF	Analog	Input voltage reference; connected to NC on this board
NC	Control	Not connected

Logical pinout · physical placement not verified

Pin details

36 connections

IO3RXDD0
Arduino D0 / serial RX; connects to ESP32 IO3
GPIO, UART
IO1TXDD1
Arduino D1 / serial TX; connects to ESP32 IO1
GPIO, UART
IO25D2
GPIO digital I/O and PWM output; connects to ESP32 IO25
GPIO
IO26D3
GPIO digital I/O and PWM output; connects to ESP32 IO26
GPIO
IO27D4
GPIO digital I/O and PWM output; connects to ESP32 IO27
GPIO
IO9D5
GPIO digital I/O and PWM output; connects to ESP32 IO9
GPIO
IO10D6
GPIO digital I/O and PWM output; connects to ESP32 IO10
GPIO
IO13D7
GPIO digital I/O and PWM output; connects to ESP32 IO13
GPIO
IO5D8
GPIO digital I/O and PWM output; connects to ESP32 IO5
GPIO
IO2D9
GPIO digital I/O and PWM output; connects to ESP32 IO2
GPIO
IO36A0
Arduino A0 analogue input; connects to ESP32 IO36
GPIO, Analog
IO39A1
Arduino A1 analogue input; connects to ESP32 IO39
GPIO, Analog
IO34A2
Arduino A2 analogue input; connects to ESP32 IO34
GPIO, Analog
IO35A3
Arduino A3 analogue input; connects to ESP32 IO35
GPIO, Analog
IO15A4
Arduino A4 analogue input; connects to ESP32 IO15
GPIO, Analog
SCK
SPI clock pin; connects to ESP32 IO18
SPI
MOSI
SPI MOSI data wire; connects to ESP32 IO23
SPI
MISO
SPI MISO data wire; connects to ESP32 IO19
SPI
SDA
I2C data wire; connects to ESP32 IO21
I2C
SCL
I2C clock pin; connects to ESP32 IO22
I2C
BCLK
I2S clock pin; connects to ESP32 IO14
Unknown
MCLK
I2S master clock pin; connects to ESP32 IO12
Unknown
DO
I2S data output wire; connects to ESP32 IO4
Unknown
DI
I2S data input wire; connects to ESP32 IO16
Unknown
LRCK
I2S LRCK data wire; connects to ESP32 IO17
Unknown
CLK
Clock pin to ESP32 IO6
Unknown
SD0
SD0 port to ESP32 IO7
Unknown
SD1
SD1 port to ESP32 IO8
Unknown
CMD
CMD port to ESP32 IO11
Unknown
IO0
Digital interface; connects to ESP32 IO0
GPIO
RST
Low-level reset port
Control
GND
Power line ground
Ground
3V3
3.3 V output; datasheet states it can provide up to 600 mA current out
PowerVoltage · 3.3V output, up to 600mA
VCC
Vi/Vo rail; 5 V when powered by USB, 3.7 V when powered by lithium battery
PowerVoltage · 5V on USB or 3.7V on lithium battery
AREF
Input voltage reference; connected to NC on this board
Analog
NC
Not connected
Control

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