Explore when and how to use all the cable ports on the Arduino* expansion board for the Intel® Edison compute module.
While plugging in every cable is not required all the time, a cable setup for initial development purposes with the Arduino* expansion board would look like the photo below:
USB Device Mode vs USB Host Mode
Before connecting USB cables to an Intel® Edison breakout board, you should know the difference between USB device mode and USB host mode.
When the Intel® Edison board is in host mode, the board acts like a computer. A USB peripheral (such as a mouse, keyboard, or webcam) can be plugged into the Intel® Edison board.
When the Intel® Edison board is in device mode, the board acts as a computer peripheral to your computer. Connect the Intel® Edison board to your computer while in device mode in order to:
- Supply 5V power to the Intel® Edison board
- Read/write to the onboard flash memory from your computer like a disk drive
- Program the Intel® Edison board over USB using the Arduino* IDE
- Program the Intel® Edison board using the Intel® XDK and Intel® System Studio IoT Edition IDEs via Ethernet over USB (instead of Wi-Fi*)
Setting the USB Mode on the Arduino Expansion Board
The hardware slider on the Arduino expansion board switches between USB device and host mode.
The microswitch is toggled down towards the two micro USB ports. A USB cable with a micro-B type connector can now be plugged into the top micro USB port and the other end plugged into your computer.
The microswitch is toggled up towards the standard USB port. A USB peripheral with a standard type connector can now be plugged into the USB port above the hardware slider. In addition, you must supply 7-15 V DC external power via the DC power barrel.
Connect to the shell on your Intel® Edison board using a serial connection via Terminal or PuTTY. Use these commands to flash firmware, configure Wi-Fi, or identify the board’s IP address.
Plug a USB cable with a micro-B type connector into the bottom micro USB port, and the other end to your computer.
Supplying External Power
The Intel® Edison board can be powered via the device mode micro USB port, an external power supply, or both.
This is especially important to note since the USB ports on some computers do not reliably supply 5V power. An external 7-15 V DC power supply is the most stable and reliable way of powering the Intel® Edison board.
If you are going to use more power intensive features such as Wi-Fi, a servo motor, or an Arduino shield, use a DC power supply. You must always use an external power supply when using USB peripherals in host mode.
You should now have a better understanding of the USB modes and cables required for development. Use your browser's back button to return to the previous article you were reading.