We have updated our wiki with 2 new tutorials :
How to use GPIO
Helios4 provides 12 GPIOs on header J12 which can be used for user application.
The tutorial will explain you how to use to the GPIOs and how to understand the mapping between physical header and the operating system.
How to use SPI
The A388 System-On-Module used by Helios4 provides an 32 Mbit SPI NOR Flash which can be used as a reliable boot device to host U-Boot bootloader.
SW1 Dipswitch
This will offer you the option to host your Root FileSystem on an USB3.0 storage device without the need to rely anymore on a microSD card.
We have work with the Armbian team to add the SPI install support for Helios4 in latest Armbian release. This way you can use the nand-sata-install utility to easily take care of setting up the SPI Flash and moving your RootFS to a USB device.
If you intend to use SPI, you should upgrade your system to latest Armbian packages with the following command.
sudo apt-get update && sudo apt-get upgrade
Also new Armbian image are available for fresh install.