TBS A711

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TBS A711
TBS A711 front.jpg
Manufacturer TBS AG
Dimensions approx. 226 mm x 122 mm x 11 mm
Release Date 2017
Specifications
SoC A83T @ 2.0 Ghz
DRAM 1 GiB LPDDR3 @ 732 MHz
NAND 8 GB (eMMC)
Power 6000 mAh 3.7V Li-Ion battery, AXP813 PMIC
Features
LCD 1024x600 (7" 16:9)
Touchscreen Multitouch capacitive FT5xxx (Focaltech)
Audio 3.5 mm TRRS microphone and headphone plug, internal speaker, internal microphone
Network WiFi 802.11 b/g/n (Ampak AP6210), combined with BlueTooth
Storage µSD, eMMC
USB 3 USB2.0 internal hosts, 1 USB2.0 OTG
Camera 1 MP front, 5 MP (2592x1944) rear
Other Accelerometer (Bosch BMA250), magnetic sensor, GPS, light sensor, fingerprint reader

Identification

There is nothing printed on the back of the device in the rectangle designed for it. There is "TBS" and logo on the front side.

The PCB has the following silkscreened on it:

A711 A83T V2.0
2016.01.20

In android, under Settings->About Tablet, you will find:

  • Model Number: Octopus A83 F1
  • Build Number: octopus_a711-eng

Sunxi support

Current status

The device is supported.

Manual build

Support in the community maintained sunxi-3.4 kernel is not planned.

Fex file patch was sent to the mailing list (https://www.mail-archive.com/[email protected]/msg21573.html).

U-Boot

Sunxi/Legacy U-Boot

Device was originally shipped with u-boot-2011.09.

Mainline U-Boot

Supported since 2018.01.

Devicetree source: sun8i-a83t-tbs-a711.dts

Defconfig: tbs_a711_defconfig

Working branch was: https://github.com/tbs-biometrics/u-boot-a711/tree/tbs/2017.07

Linux Kernel

Sunxi/Legacy Kernel

Allwinner kernel 3.4.39 was used.

Mainline kernel

Starting 4.15 there is sun8i-a83t-tbs-a711.dts devicetree source in mainline.

Working branch for basic support: https://github.com/tbs-biometrics/linux-a711/tree/tbs/4.13

Working branch for CSI support: https://github.com/megous/linux/tree/linux-tbs

Tips, Tricks, Caveats

LCD and touch issues

There were a few revisions of the board. The changes were in the LCD timing (timing changes just in the fex file) and a touchscreen configuration (ctp_exchange_x_y_flag and ctp_revert_*_flag were inverted).

FEL mode

There is a footprint labeled UBOOT on the board. It is located near the CPU. It is not tested but it should be usable to go into the FEL mode.

Adding a serial port (voids warranty)

TBS A711 UART connector

There is an easily accessible UART receptacle on the board (you need to disassemble the tablet to access them).

Device disassembly

  1. There are four screws on the sides of the tablet. Unscrew them.
  2. You need to pop the pins to remove the back side. Plastic tool is very helpful.

Locating the UART

UART recetacle is labeled UART0 and it is located near the soldering pads for vibrator. It operates at 3 V. See the image for the pin assignment and UART howto for more information.

Pictures

Miscellaneous

Some tablets were donated to the community. The number of tablets for community is limited now (this may change in the future). See https://www.mail-archive.com/[email protected]/msg21568.html.