EPD on Tinkerboard

[alr2000]

Hi, I´m trying to port the EPD device code for Tinkerboard.
I´m using Tinkerboard 1.9 OS. The gpio pins are fully compatible with the one on raspberry pi. I adapted the gpio.c and edp_io.h to match the tinkerboard gpio and spi device. But when I run the epd_test 2.0 I get:

I used this epd device on raspberry with the epd_test 2.0 without problems.

After a few test I discover that the spi behavior on Tinkerboard differs from Raspberry pi and the one indicated in the DS.
I send 3 bytes[0x80,0x82,0x81] with mode 0 and bit 8 bits per word, with no delay on raspberry:

I send 3 bytes[0x80,0x82,0x81] with mode 0 and bit 8 bits per word, with no delay on tinkerboard.

As you can seen the raspberry does a clock pause between each byte, but the tinkerboard doesn´t do this pause. Could it be the problem? I don´t now how sensitive is the clock pin on the display, but according with the DS, the behavior should be like the raspberry.

I did a post on PiSupply/PaPiRus#140 where there is more info about the issue.

@repaper @CharmingSu

[shawaj]

The fix for this is shown here

PiSupply/PaPiRus#140 (comment)

We should incorporate into gratis repo at some point