Hyundai A7HD

The Hyundai A7HD is a 7" Allwinner A10 tablet with a 1024x600 IPS panel. It comes with 1GB ram, and can be found on the likes of aliexpress and ebay quite regularly.

= Sunxi support =

Current status


It works!

Warning: when trying to boot from SD: first halt the machine fully through the powerbutton, then also unplug serial, otherwise it will try to keep on booting from nand.

Images
Add Hyundai A7HD specific images here.

A Mer build is being worked on!

HW-Pack
Add Hyundai A7HD HW-pack specifics here.

BSP
Add Hyundai A7HD BSP specifics here.

FirstSteps full build specifics

 * For building u-boot, use the "hyundai_a7hd" target.
 * The .fex file can be found in sunxi-boards under hyundai_a7hd.fex

Everything else is the same as the mele example in the howto.

Bumping DRAM clock
Most allwinner devices happily accept 480MHz as the DRAM clock, yet the DRAM tends to be clocked in the original fex at 360MHz. There is a measurable difference in performance when boosting the DRAM clock.

Edit board/allwinner/hyundai_a7hd/dram.c in the u-boot tree, and change the following:

@@ -4,7 +4,7 @@ static struct dram_para dram_para = { -      .clock = 360, +      .clock = 480, .type = 3, .rank_num = 1, .density = 2048,
 * 1) include 

Now build and install u-boot as in the FirstSteps guide, and your machine will be slightly more performant.

= Adding a serial port =

Put the hyundai with the glass front down on a clean flat surface. It is relatively easy to pop the aluminum back off. As always with devices with plastic clips, use a piece of plastic (cut the end off a toothbrush to look like a flat screwdriver for instance), to not damage the device more than needed. Loosen the strips of tape, remove the 8 screws, gently open the two ribbon connectors to the display and the touchscreen, and flip the motherboard to one side, but be careful with the backlight connector.

Now you should be able to see the serial connector:



The right one is GND, the two in the middle are TX and RX, these are the only signals that you need to extend out to your TTL serial dongle. Be very careful when soldering!

Run the wires along the battery to the left side of the device, where there is still some space for wires. Make sure that the wires run flat next to eachother along the board so that they fit between the board and the display.

If you like a cleanish job, you can drill a hole in the plastic in the bottom. Do not do the obvious thing, like me, as that is just stupid. Drill a hole near the lower left corner of the screen (red arrow). This way the pressure on the display will be kept to a minimum (uneven backlighting) and the device might fully close again.



Now flip rx/tx about until you have a signal on your serial!