OLIMEX© 2015
A20-SOM user's manual
CHAPTER 2: SETTING UP THE A20-SOM BOARD
2. Introduction to the chapter
This section helps you set up the SOM development board for the first time. Please consider first
the electrostatic warning to avoid damaging the board, then discover the hardware and software
required to operate the board.
The procedure to power up the board is given, and a description of the default board behavior is
detailed.
2.1 Electrostatic and electrical polarity warnings
A20-SOM boards are shipped in a protective anti-static package. The board must not be exposed to
high electrostatic potentials. A grounding strap or similar protective device should be worn when
handling the board. Avoid touching the component pins or any other metallic element.
Ensure that your development board gets attached to properly working hardware. If this is not
possible please use isolators (like USB-ISO) to save your development board from potential over
voltage.
If you connect other electrical devices to the SOM board make sure that they have equal electrical
polarity. For example, when you connect a serial cable connected between a PC and the board's
DEBUG port it is a good idea to have them both connected to the same electrical source (to the
same utility power socket). In rare cases different polarity might cause hardware damage to the
board.
2.2 Requirements
In order to set up the A20-SOM board optimally one or more additional items may be needed. They
might be generally placed in two categories:
Required
– items that are needed in order to achieve minimum functionality;
Recommended
– items that is good to have in order to be able to interact with the most important
of the features of the board;
Note that if A20-SOM is mounted on A20-SOM-EVB – the requirements would be different! The
requirements below are for a stand-alone use of A20-SOM. Refer to A20-SOM-EVB's user's
manual for adjusted requirements.
Required items:
- 5V-external power supply with proper connectors – A20-SOM has no power jack, only powering
pins (5VEXT, GND)
- Output device – USB-SERIAL-CABLE-F + personal computer with serial terminal program –
A20-SOM lacks other options for debugging – you would need a serial cable that can work at the
CMOS levels of the board's signals
- SD card with compatible image – if you have the board version with NO additional NAND
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