Olimex A20-SOM

Olimex A20-SOM
Manufacturer	Olimex
Dimensions	85mm x 54mm x 5mm
Release Date	May 2014
Website	Product page
Specifications
SoC	A20 @ 1 Ghz
DRAM	1GiB DDR3 @ 384MHz
NAND	4GB (optional)
Power	DC 6-16V @ 3A
Features
Video	HDMI (Type A)
Audio	3.5mm headphone plug, 3.5mm microphone plug, HDMI
Network	10/100Mbps Ethernet (Realtek RTL8201CP)
Storage	µSD, SD, SATA
USB	2 USB2.0 Host, 1 USB2.0 OTG
Other	2KiB EEPROM
Headers	UART, ...

Olimex A20-SOM is an A20 based development board from our friends at Olimex.

Identification

The board helpfully reads "A20-SOM".

Sunxi support

Current status

Supported.

Manual build

• For building u-boot, use the Olimex_A20-SOM target.
• The .fex file can be found in sunxi-boards as olimex_a20_som_evb.fex

Everything else is the same as the manual build howto.

Tips, Tricks, Caveats

FEL mode

The Recovery button triggers FEL mode.

LDO3 (Port E / CSI0 Power Supply) Problem

When the A20-SOM is connected to the A20-SOM-EVB base board sold by Olimex and the LDO3 of the AXP209 chip is initially switched off by uboot (which newer uboot versions do by default), LDO3 should never be re-enabled. Doing so leads to immediate shut down of the AXP209 resulting in a crash of the board. The reason seems to be too much capacitance on the lines connected to the LDO3 output and non-effective voltage rate control on the AXP209 for LDO3, leading to excessive inrush currents and triggering the overcurrent-protection of the AXP. See this thread on the mailing list for more details: https://groups.google.com/d/topic/linux-sunxi/EDvEsbHHqQI/discussion

Adding a serial port

UART connector

A nicely labeled UART connector is available, all you have to do is attach some leads according to our UART howto.

Pictures

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Also known as

This type of device does not get rebadged.

See also

• Our local Olimex page showing all other Olimex products.
• Original announcement on Olimex's blog.
• Schematics and various docs