Gravity IO Expansion Shield for FireBeetle 2 Series Wiki - DFRobot


Specially designed for FireBeetle 2 series, this Gravity IO expansion shield offers various ports including digital, analog, I2C, UART, SPI, etc. Also, it comes with power input socket for connecting external power supply as well as EN pin for cutting off the power supply to main-board. The Gravity IO shield allows a convenient connection between DFRobot Gravity sensors and FireBeetle 2 series, no soldering required.



Function Description

The following instructions are only for the Arduino environment. If use it in other operating environment, please adjust the usage according to the schematics.

3.1 Digital ports

This IO expansion shield provides 12 groups of digital ports including 0~13 except 4 and 8, which can be used directly by IO number.

Note: When ESP32 uses pins in the Arduino environment, you need to use Dx such as D0 instead of directly using IO number 0, or use IO number corresponding to the mainboard.

3.2 Analog ports

This IO expansion shield provides 5 groups of analog ports including A0~A4, which can be used directly by IO number.

3.3 I2C ports

This shield provides 3 groups of I2C ports in parallel.

3.4 UART ports

This shield provides 1 group of UART ports. R corresponds to pin 0, T to pin 1. When using UART, please do not use pin 0 and pin 1.

3.5 SPI ports

This shield provides 1 group of SPI ports, supporing to use SD card module in-line, and SS is connected to pin 6.

3.6 SP pin

The SP pin presents different functions on different mainboards, representing NC, RXD, TXD, A5 on M0, and I2C on ESP32-E.

3.7 GDI display interface

This interface is a DFRobot dedicated GDI, with 18pin-FPC cable connection and single wire connection to the screen, providing you with the simplest way to use the screen.

The following is a list of pins used by the GDI interface

FPC PINS Standard IO Expansion Shield Line Sequence
VCC display power 3.3 V
BLK display backlight 12/D13
SCIK SPI clock 18/SCK
MOSI SPI host output 23/MOSI
MISO SPI host input 19/MISO
DC data/command 25/D2
RES reset 26/D3
CS display chip select 14/D6
SDCS SD card chip select 13/D7
FCS font library chip select 0/D5
TCS touch chip select 4/D12
SCL I2C clock 22/SCL
SDA I2C data 21/SDA
INIT initialization 16/D11
BUSY-TE anti-tear pin 17/D10
X1 extensible pin 1 NC
X2 extensible pin 2 NC

When using the FPC to connect to the screen, configure the corresponding pin number according to the GDL demo, usually only three pins are required for configuring.

Displays supporting GDI:

For specific usage, please refer to: GDL display wiki:

NOTE: Please do not reuse related pins. The GDI on the expansion shield only supports ESP32-E. If you need to use GDI for M0, please use the GDI integrated on the development board.

Power socket and EN switch

VIN: Connect to the VCC pin on the mainboard. The terminal is convenient for connecting the spiral battery. Note: When VIN is connected to an external power supply, do not connect the main control to other power supply or USB.

GND: Common ground

EN: It can be designed as the maincontroller switch. When EN is grounded, the main controller will stop running.


For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

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