search

repaper / gratis

EPD Source codes and Documentation
238 stars 132 forks source link

EPD on Tinkerboard #75

Open alr2000 opened 7 years ago

alr2000 commented 7 years ago

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:

28558861-25c8d6fe-7114-11e7-9779-fea3d4c8361f

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: img_1845 I send 3 bytes[0x80,0x82,0x81] with mode 0 and bit 8 bits per word, with no delay on tinkerboard. img_1847

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. 28871583-873cdfd0-7785-11e7-9cc1-b1803a51a0bc I did a post on https://github.com/PiSupply/PaPiRus/issues/140 where there is more info about the issue.

@repaper @charmingsu

shawaj commented 7 years ago

The fix for this is shown here

https://github.com/PiSupply/PaPiRus/issues/140#issuecomment-323815041

We should incorporate into gratis repo at some point