BELK-AN-005: Interfacing BoraEVB to thin film electroluminescent display
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Contents
History[edit | edit source]
| Version | Date | BELK version | Notes |
|---|---|---|---|
| 1.0.0 | 2.2.0 | First release |
Introduction[edit | edit source]
This application note shows how to interface BoraEVB to 5.7" thin film electroluminescent display Lumineq EL 320.240.36-HB. This project is based on 2.2.0. Reading of AN-BELK-004 is recommended since many concepts are shared by these two application notes.
For more information about Lumineq part, please refer to http://lumineq.com/en/product-tags/diagonal-size-57-2.
Physical interfacing[edit | edit source]
To interface the display a small adapter board is needed. On BoraEVB side it is connected to JP17 and JP23 headers. It connects to display through a flat cable that is plugged onto JP3 header. At this URL TBD schematics are available for download.
Also the following changes need to be made on BoraEVB in order to provide LCD 12V and 5V power supplies:
- remove D12, D13, RP62, RP64
- wire D1.1 to JP23.2
- wire D1.1 to JP23.4
- wire C164.1 to JP23.1
- wire C164.1 to JP23.3
Block diagram and Vivado design[edit | edit source]
The following picture shows simplified block diagram of the design. In principle the structure of the design is the same of the one described in AN-BELK-004.
TBD
LCD is driven by a controller implemented in PL that fetches pixel data from frame buffer and periodically refreshes physical screen. LCD controller provides configuration registers that are mapped in the following address range: TBD
To implement frame buffer, a portion of main SDRAM is used. This area is allocated at runtime by linux frame buffer driver.
At the following URL the Vivado design is available for download: TBD. Please note that, even if this application note is based on BELK 2.2.0, this design has been implemented with Vivado 2013.4
Enabling frame buffer driver in linux kernel[edit | edit source]
To enable frame buffer driver TBD
During kernel bootstrap, the following messages are printed out on console, indicating framebuffer driver has been loaded succesfully:
TBD
Once the kernel has completed boot, frame buffer can be accessed from user space applications via /dev/fb0 device file (for more details please refer to https://www.kernel.org/doc/Documentation/fb/framebuffer.txt).
The following image shows Qt 4.??? demo application running on top of it. TBD
