Skip to content
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
27 lines (20 sloc) 1.73 KB

Wiring of weather shield to DragonBoard 410c


In this project, we will use a weather shield containing a HTU21D(F) humidity and temperature sensor and a MPL3115A2 pressure sensor connected to a I2C bus. We will use the SparkFun weather shield, which provides these two sensors and a light sensor. The GPIO of the DragonBoard includes the required I2C buses and 5V port to power the shield.

A push button will be connected to the GPIO. It will be used to activate voice recognition for operation without a keyboard and mouse.


To connect the sensor to the DragonBoard, a level shifter will be necessary. The DragonBoard GPIO operates at 1.8V, while the weather shield outputs operate at 5V. A bidirectional level shifter is required due to the open drain nature of I2C, where both the master or the devices might pull the line low. A Adafruit 4-channel I2C-safe Bi-directional Logic Level Converter will be used.


The Fritzing project with the connections can be downloaded here. Breadboard wiring

  • The GND signals of both boards are connected.
  • On the DragonBoard side, LV is connected to 1.8V, and A1 and A2 are connected to SCL and SDA, respectively.
  • On the weather shield side, HV is connected to 5V, and B1 and B2 are connected to SCL and SDA, respectively.
  • The DragonBoard's 5V output is connected to 5V and VIN of the weather shield.
You can’t perform that action at this time.