A20-OLinuXino-LIME-4GB is a single-board computer in a very compact form. It uses the Allwinner Technology A20 Dual-Core ARM Cortex-A7 processor, and can run Arch, Gentoo, OpenWRT, Debian, Tizen, Ubuntu, and Fedora Linux distributions — as well as Android 4.2.2.
This board is basically the same as the A10-OLinuXino-LIME-4GB but with a dual-core Cortex-A7 processor in place of the single-core Cortex-A8. The result is a board that is almost twice as fast as the A10 LIME while consuming about 25 percent less power. If you want even better performance, consider the A20-OLinuXino-LIME2-4GB which is even faster, doubles the memory, and has Gigabit Ethernet.
This open-hardware board is a great alternative to Raspberry Pi or BeagleBone. It provides SATA, HDMI, 2x USB Hosts, USB-OTG, native Ethernet, 160 GPIOs, plus a connector for a TFT LCD and the ability to be powered by a LiPo battery — complete with built-in charging circuit. It can be powered by battery, USB-OTG or though a barrel jack to a regulated 5V DC supply. The latter two sources will recharge a connected LiPo battery also.
The whole thing isn't much larger than a credit card. In the options below, you can add a plastic case that encloses the system into a nice-looking "finished" product.
Download LIME vs Raspberry Pi Comparison (comparing the original A10 LIME specs)
This tiny computer does not come with a pre-built OS, though this version does come with 4GB NAND Flash. The NAND Flash can be used for the proprietary Android bootloader from Allwinner, a custom Android OS image for this board (download from Wiki), or as storage in Linux using the working MTD driver. The ability to boot Linux from NAND Flash has not been achieved yet. It can boot from a microSD card. Pre-built Debian Linux and Android SD card images are available to download (as well as the Android NAND image). In the Optional Recommended Products list at the bottom of this page, you can choose to add microSD cards with the SD images already installed.
In addition, the official Debian 8.0 Jessie release now has a Device Tree Blob specific to this board. However, it is designed to run from a microSD card; running it from NAND Flash is not supported.
This board is an open-source hardware and software project; see the links below to participate in the development discussion.
A20 Single-Board Computer Features
NOTE: The input through the power jack must be a regulated 5V DC supply. It is a 2.5mm barrel connector, positive inner. You can use the MIKROE-192 voltage regulator/rectifier board and the PWR-CABLE adapter for an easy, solderless solution if you don't have a regulated 5V supply available. The board also can be powered from the USB-OTG port or by a LiPo battery.
- A20 Dual-Core Cortex-A7 CPU 1GHz and Mali 400 GPU
- 512MB DDR3 RAM
- 4GB NAND Flash memory
- SATA connector with 5V SATA power jack
- HDMI connector with FullHD support (1080p)
- 2x USB High-Speed Host with power control and current limiter
- USB-OTG with power control and current limiter
- 100Mbps native Ethernet
- LiPo battery connector with battery-charging capabilities (see compatible batteries)
- LCD connector (see Display Options below)
- 160 GPIOs on four GPIO connectors with 0.05" pin spacing
- microSD card connector
- DEBUG-UART connector for console debug with USB-to-Serial cable (see options below)
- GPIO LED
- Battery charge status LED
- Power LED
- 2KB EEPROM for MAC address storage and more
- Buttons for Android functionality
- Reset button
- 4 mounting holes for optional case (see options below)
- 5V input power supply; noise-immune design
- Dimensions: 84 × 60 mm
Lime Board Layout An A10 LIME is shown; the layout of the A20 LIME is identical. This image shows a version without the NAND Flash installed.
A20 Single-Board Computer Resources Because the boards are nearly identical, A10 LIME documentation is provided where A20 LIME documentation does not exist yet. Note that the current Debian Linux build has Ethernet disabled by default, to improve boot speed for those not using it. The Wiki page has instructions for enabling the Ethernet controller.
WARNING: If your HDMI TV does not have a grounded power supply, it can damage the OLinuXino board. If you can't use a grounded TV, add the 1000V DC USB Isolator between your PC's USB2.0 port and the USB-to-Serial Cable, and keep that cable connected to the OLinuXino board. The cable and the isolator can be purchased from the options below.
Display Options If you want to use one of the optional LCDs listed below, you'll also need the 0.05"-pitch 2x20 IDC Ribbon Cable to connect it, so be sure to select that in addition to the display. The 15.6-inch display will require a dedicated external 5V supply as well. Please take note of the following:
For Linux: In the pre-built image available from the Wiki page (or on the SD card listed below), the default display setting is for HDMI 720p @ 60Hz. The Wiki page has instructions for changing to an LCD or VGA display (or for changing the HDMI settings, e.g. to 1080p).
Optional Recommended Products for this Item
|Plastic Box for A10-OLinuXino-LIME, Enclosure with End Plates||+|| US$12.85|
|Bootable microSD Card with Debian Image for A20-OLinuXino-LIME||+|| US$13.99|
|Bootable microSD Card with Android Image for A20-OLinuXino-LIME||+|| US$13.99|
|GPIO and LCD Port Adapter for OLinuXino-LIME, Plus UEXT Port||+|| US$4.45|
|2x20 (40-pin) 0.1||+|| US$8.52|
|2x20 (40-pin) 0.05||+|| US$9.49|
|4.3-inch LCD Touchscreen for OLinuXino and LIME/LIME2, 480x272||+|| US$49.50|
|Frame Kit for 7" LCDs, e.g. Olimex A13-LCD7||+|| US$7.55|
|10-inch LCD for OLinuXino and LIME/LIME2, 1024x600||+|| US$95.89|
|10-inch LCD Touchscreen for OLinuXino and LIME/LIME2, 1024x600||+|| US$95.89|
|15.6-inch LCD for OLinuXino and LIME/LIME2, 1366x768||+|| US$95.89|
|15.6-inch LCD for OLinuXino and LIME/LIME2, 1920x1080||+|| US$95.89|
|USB-to-Serial Cable, 6 Female Header Wires, 3.3V I/O||+|| US$14.90|
|1000V DC USB Isolator||+|| US$42.45|
|Polymer Lithium Ion Battery, 850mAh, JST Connector||+|| US$9.95|
|Polymer Lithium Ion Battery, 2000mAh, JST Connector||+|| US$16.95|
|Polymer Lithium Ion Battery Pack, 6Ah, JST Connector||+|| US$29.95|
|HDMI Cable, 6 ft., Standard, A Male to A Male||+|| US$4.95|
|USB 2.0 Cable, 6ft., A-Male / B-Male||+|| US$6.00|
|USB 2.0 Cable, 6ft. A-Male / Mini-USB (5-pin) B-Male||+|| US$6.00|
|USB 2.0 Cable, 6ft. A-Male / Micro-USB (5-pin) B-Male||+|| US$6.00|
|Ethernet Cable, CAT5E 350MHz Unshielded, 7ft.||+|| US$3.60|
|Ethernet Crossover Cable, CAT5E 350MHz Unshielded, 5ft.||+|| US$7.00|