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by 1n4148
Thu Jul 07, 2016 7:55 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

Did you try already "play captured" init from RPi? Did you manage to to "display something" after "playing init"? On my last setup I've captured the whole display traffic into an SDRAM attached to the FPGA and was able to playback the sequence until the desktop is up without an RPi. But during deco...
by 1n4148
Thu Jun 30, 2016 11:17 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

Unfortunately I've cracked my screen when I accidently droped it from my lab bench so I can tell you the display is a YXT35MH357-A, photo from the layout side will follow
by 1n4148
Thu Jun 30, 2016 10:31 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

I've put the first captures into my github: https://github.com/1N4148/Kedei
by 1n4148
Thu Jun 30, 2016 8:40 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

The result would be the same, I'm emulating the shift registers in a FPGA using the build in Signal Tap II analyzer to store only latched data, instead of fiddling around with a lot of wires. Ignore the timestamp in the csv-file, it's not true. Every line is the actual output of the shift register a...
by 1n4148
Tue Jun 28, 2016 8:12 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

So, made the first init-captures with my quick & dirty FPGA based TFT sniffer (basically implemented 3x595 in HDL, capturing only the data which is on the outputs after L_CS has risen) Captured to boots from a V6.0 image. The start may differ as there is some junk on the line as I've seen on the sco...
by 1n4148
Mon Jun 27, 2016 6:53 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

One you have this figured out and got some understanding where to look at what, try run other kernel versions for earlier lcd's. It's very hard to get a good signal, the L_CS pulse is very short so at the necessary high sample rate my OLS logic analyzer runs out of memory quickly. A cypress USB bas...
by 1n4148
Mon Jun 27, 2016 4:17 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: KeDei 3.5 inch 480x320 TFT lcd from ali
Replies: 235
Views: 208064

Re: KeDei 3.5 inch 480x320 TFT lcd from ali

I'm currently hogging logic analyzer to a V6.0 display. I'll post the results later. Also I'll try to get some good photos of the PCB.

Tried this board with driver V6.1 which results in all colors inverted. It seems they're changing something on a regular base to make reverse engineering hard.

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