{"action":"opened","issue":{"url":"https://api.github.com/repos/olikraus/u8g2/issues/840","repository_url":"https://api.github.com/repos/olikraus/u8g2","labels_url":"https://api.github.com/repos/olikraus/u8g2/issues/840/labels{/name}","comments_url":"https://api.github.com/repos/olikraus/u8g2/issues/840/comments","events_url":"https://api.github.com/repos/olikraus/u8g2/issues/840/events","html_url":"https://github.com/olikraus/u8g2/issues/840","id":421958766,"node_id":"MDU6SXNzdWU0MjE5NTg3NjY=","number":840,"title":"U8G2 with STM32 and 12864B LCD over SPI Displaying Random Pixels","user":{"login":"berndoJ","id":22524202,"node_id":"MDQ6VXNlcjIyNTI0MjAy","avatar_url":"https://avatars3.githubusercontent.com/u/22524202?v=4","gravatar_id":"","url":"https://api.github.com/users/berndoJ","html_url":"https://github.com/berndoJ","followers_url":"https://api.github.com/users/berndoJ/followers","following_url":"https://api.github.com/users/berndoJ/following{/other_user}","gists_url":"https://api.github.com/users/berndoJ/gists{/gist_id}","starred_url":"https://api.github.com/users/berndoJ/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/berndoJ/subscriptions","organizations_url":"https://api.github.com/users/berndoJ/orgs","repos_url":"https://api.github.com/users/berndoJ/repos","events_url":"https://api.github.com/users/berndoJ/events{/privacy}","received_events_url":"https://api.github.com/users/berndoJ/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":0,"created_at":"2019-03-17T18:50:14Z","updated_at":"2019-03-17T18:50:14Z","closed_at":null,"author_association":"NONE","body":"Hello,\r\n\r\nso I've followed the porting guide ([https://github.com/olikraus/u8g2/wiki/Porting-to-new-MCU-platform](url)) on how to port u8g2 to a custom MCU platform. In my case I use an STM32F072RBT7 (ARM Cortex-M0 Core) STM32-MCU.\r\nIt seems that my port of the hardware dependant functions at least kinda works, as data is pushed out over spi. (I checked it with an oscilloscope)\r\nThe problem is that after the init of the display random pixels are displayed on screen, with 32 pixel wide white / inverted areas. (see image).\r\n\r\nI use an 12864B 128x64 graphical LCD (I think its even the same one as in the SPI example of the setup tutorial), driven over SPI (SCK, MOSI, CS, RST), which uses the ST7920 LCD-Controller. As I've succeeded in driving this exact LCD with an Arduino before, this LCD is known good.\r\n\r\nAs firmware I use FreeRTOS and STM32CubeMX, which generates the HAL libs for my STM32 device.\r\n\r\nI don't know if it is the issue of my hw port or if something different is going on...\r\n\r\nImage of the LCD after init:\r\n![lcd](https://user-images.githubusercontent.com/22524202/54496203-d4222500-48ec-11e9-828c-6e6ce2aa61c7.jpeg)\r\n\r\ndisplay.c : Here the u8g2 is initialised.\r\n[display.c.txt](https://github.com/olikraus/u8g2/files/2975553/display.c.txt)\r\n\r\nu8g2_stm32_hw_port.c : here are the functions used to port u8g2 to my device.\r\n[u8g2_stm32_hw_port.c.txt](https://github.com/olikraus/u8g2/files/2975557/u8g2_stm32_hw_port.c.txt)\r\n\r\nThanks in advance,\r\nberndoJ"}}
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