What kind of UMPC can you get by rummaging through flea markets?

Hi all! So the next part of my series of articles on very cheap devices came up, which I always try to find a use for. And this time, I want to show you another cool side of online flea markets (so as not to be advertising – I don’t mention the names, but you guessed it yourself). The Chinese are doing a lot to make the UMPC market as cheap and accessible as possible – Lctech released their highly integrated Pi Zero board on the AllWinner F1C100S sandwich – which already has 32 / 64MB of RAM built in, and the price of which is about 900 rubles on AliExpress. I propose to assemble the UMPC for 100-500 rubles, and without a single clickbait, on much more powerful hardware and with built-in Wi-Fi, sometimes 3G, a full USB stack and built-in NAND memory 4-8GB. Interesting? Welcome to the cat!

Description

There are many SoC manufacturers in the Chinese market – and most of them started releasing their solutions 10-12 years ago. These are VIA with their WonderMedia (remember those mini-laptops on WinCE / Android for 2000 rubles?), and Rockchip, with their very inexpensive chipsets for tablets and e-books, and Amlogic, now popular in the field of TV set-top boxes, used to be very many tablets and game consoles (reviews for which I have in my profile) – thanks to the 8726-MX chip.

There was also GeneralPlus – which is funny, their full-fledged SoCs were produced in a TSOP package, but disappeared somewhere after their GP33003 chipset. And among these companies was the young company AllWinner – which introduced its A10 and A13 chips, which quickly became very popular on the market among cheap tablets. Remember Chinese tablets for 2-3 thousand rubles, with batteries from the back? Or fake iPads?

Most likely, they worked on the same allwinners/rockchips. Then there were tablets on media libraries, but they are of much less value within the framework of this article. Why? More on that below.

Purchase

At the beginning of the article, I wrote that the budget of our umpc is 100-500 rubles. We go to Avito or Yulu, select our city and write in the search “tablet for parts”. We visually look at old models (usually 7 inches) and with HDMI output (this is important, and there were a lot of such tablets), google the characteristics on which processor they work. We need BoxChip Axx/AllWinnerAxx. Someone will say “so wait, they are for spare parts”, and I will answer: ordinary people have typical malfunctions associated with such tablets – the charging socket has broken / the battery has died / the firmware has flown (we won’t need it at all, the device is loaded in priority from an SD card without any problems), the display is broken (it doesn’t matter, because there is HDMI). This is all fixed very easily, for example, you can power the tablet directly from 5v charging by simply throwing a plus and a minus (or you can act wisely – solder the battery from Nokia – it will serve as a kind of UPS. But usually the batteries in such tablets are not quite dead, and they are enough to work from the network directly and from the battery for 30-40min). Bought? And what did we get?

Wi-Fi module, usually soldered as USB.
Sometimes 3G module. Proprietary, there are no docks on them, but in Linux they are seen out of the box and without any problems. Might be useful for alarms or something like that.
Display. TTL displays are very cheap if you know where to look) Cheap chipsets did not support any MIPI at that time, except perhaps amlogic through a chip layer. I won’t post links – if you’re interested, they’ll write a PM.
4-8GB of built-in NAND memory, where you can also put the system if you wish. And you can make a dual block with a built-in android.
Full usb stack. Sometimes the board has leads for desoldering the USB connector (like mine), in other cases, you can unsolder the Wi-Fi module and solder the hub boards from Ali for 100 rubles and get several connectors. You can use otg cables. The only caveat is 3.3v power, this is allowed by the standard, but usb hdd will not work, for example.
Built-in audio codec with microphone and speaker, as well as support for CSI cameras (albeit not the best quality).

Impressive? Great, welcome below.

Environment setup

The main advantage of AllWinner and AMLogic chipsets over any media libraries is the built-in ability to boot from an SD card, and AllWinner had its own kernel config before dtb, which allowed you to configure almost all peripherals. It was called conifg.fex, and the kernel was, as it were, universal for all chipsets. And therefore, for almost all chipsets of this vendor (even such old ones as A10) there are drivers in the mainline kernel.

Here is a Yandex disk with a bunch of already configured and installed images:

https://disk.yandex.ru/d/FtZBeN4NrhuwB

I initially downloaded lubuntu – but I do not recommend it, there is ABI armel, which has not been supported for a very long time. And yet there are no drivers for Mali (GPU) and cedar (decoder) video.

Download Win32DiskImager (or write directly via dd) and write the image to a flash drive:

The flash drive must be 4GB or more. I do not recommend taking very Chinese dead cheap flash drives – they can die during the recording process (or already even in the system) and go into ridonly.

We insert microHDMI -> HDMI into the device, insert the USB flash drive, press the power button and … nothing. And all because some distributions include HDMI output already when lightdm is loaded (you can enable instant output to HDMI in config.fex and turn off the backlight / output to a broken display).

Nothing showed up? Then try lubuntu from the link above – not all kernels are compatible. Lubuntu worked hard for me and you can start with it to check.

Input

It is not a fact that the native touch of your device will work (or rather, it is almost unrealistic), so we need a mouse with a keyboard. How to connect it? We take an otg cable (you can make it yourself if you wish, or buy it in the DNS for 100 rubles) or unsolder your hub in place of the wi-fi module

We take the hub, connect the mouse and keyboard … and voila – everything works. Perhaps some old mice or keyboards require 5v iron, but all modern ones work fine from 3.3. We enter the system:

The standard ubuntu ports repository does not contain packages for ubuntu precise for a long time. However, old-releases still holds packages for the officially dropped in 2013(!) armel ABI. In the standard delivery there is Firefox (very slow, focusing on both percent and memory – the percent heats up to 60 degrees, then starts throttling). I collected a quake of interest for the sake of a fresh compiler, but it did not start, but openarena from the repositories worked ~ 2FPS. Alas, most distros do not have drivers for Mali, and we will not get 3D or at least a smooth interface – you need to collect firewood and a framebuffer driver by hand. I didn’t do this – it’s very hemorrhoid to do on fresh distra, and compiling something on the tablet itself is suicide. Even hardware codecs cannot be started without compiling these codecs themselves;)

We press the standard configuration Ctrl + Shift + T, and we get into the terminal. Here, the list of features available to us depends on the distro we have chosen (and the availability of the cedar / mali driver):

What is originally in any distribution, and what can be done without drivers:

Network, both 3g and wifi.
Compile any software with GCC.
Surf the Internet through FireFox (without firewood, the brake is the same, especially on devices with 512MB of RAM)
Deploy a web server, file storage (very budget), in short, everything related to the network infrastructure – there are good ports.
Listen to music

What can be done with drivers:

Watch videos up to 1080p through VLC. Of the codecs, there is definitely h264
Youtube (a stretch for A10, newer ones pull it easily)
Play ports of games: SuperTux, Quake 3, etc. – in short, the entire game library from raspberries is available. Retropay is also here – the console easily pulls emulation up to ps1 / gamecube.

What about GPIO? Without GPIO it’s not UMPC.

On the boards, the UART is often soldered. So why not buy an arduino and make a simple one IO Expander, and not get the opportunity to pull any pins in user-mode? Pro Mini costs 300 rubles.

Android

Android is usually on the internal memory (sometimes killed – in this case, flashing from the same SD card or from a PC helps.). Usually this is version 4.0.3 (as in my case), but it can be higher. What could be its advantage? It can do virtually everything that can be done under ordinary Linux (and deploy the network, compile programs, surf the network with sufficient comfort), but at the same time, it immediately contains all the necessary blobs, and allows you to make a media station out of the device without crutches (with FHD support). video) / game station with emulators. Android is perfectly controlled both with the mouse and with the keyboard, and even with the gamepad. In addition – we get a collection of Android games, albeit not the most recent ones. It turns out a kind of TV box, but not for 2-3-4 thousand rubles, but for 5 packs (and sometimes half a pack) of cigarettes 🙂

Results

If you have always been interested in trying what miniature PCs are, but fork out 3-4k rubles for a raspberry. if you didn’t want to, then that’s quite an option) Such a UMPC is suitable for many purposes, and it costs practically nothing, and the list of applications is not limited to multimedia: you can, for example, make a simple video surveillance system with a GSM alarm. What about your opinion?

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