Asus ME571K aka Nexus 7 (2nd gen) touch digitizer reverse engineering (introduction)
When 1st Google Nexus 7 was released in 2012 there was so much hype about it, official Google tablet (made by Asus) , latest Android update and powerful hardware based on nVidia Tegra 3 was perfect little Android tablet with enough power (at time).
Nexus 7 (codename ME370T) with 7" display (1280x800 IPS LCD), really nice response and sharp viewing angles catch my eye and later on I tough will be super nice to have that screen for RPi based projects or in general if there was some driving board.
As LCD was driven with LVDS signals there was no small boards that would be perfect fit to use with HDMI, there was some tryouts with boards but nothing with touch capabilities.
I went to research and find ME370T schematic online (here is LINK) and saw there is complete schematic for touch but a bit messy as RAW digitizer needed whole circuit to be able to get I2C from it. (open pdf and check page 29)
As you can see there is 2 IC that drive touch detection (EKTH1036 and EKTF3624), except that you need power circuit and two 31 pin connectors. So in general too much hustle for something you can find it online (that would fit). On AliExpress you could find alternative for ~6-10£ that would be perfect but still we have driving board issue.
So after that I have decided to abandon 1st gen and try to involve more with 2nd gen Nexus 7 codename ME571K (there is few iteration ME571KL...).
2nd gen was a bit harder to get hardware info (except what we knew from tech spec) as was release 1 year later with bumped spec but same size 7" IPS LCD but this time screen resolution was much better 1920x1200 what result 16:10 screen ration :)
To find something useful (schematic wise) online for ME571K was not so easy and required to pay even on some places to download service manuals to get data. Had some success on Russian forums but not enough.
So I decided to get from eBay some broken one and get sub board that I know from iFixit tear down. Went on eBay and for 15-20£ you could get some broken one but I was fishing for one that have 100% LCD working (so can be reused).
After few tries got one with delivery less than 15£ (digitizer was cracked but screen was working) and I was so happy to get it so cheap (as LCD only worth more than that).
Now waiting for eBay delivery to get it and than will make part 2 with tear down, desoldiering IC and try to find/map pins for digitizer.
Stay tuned to 2nd part...