Hello,
Correct, once you export from ESD to Eclipse there is no way to get it back into ESD.
ESD includes a lot of framework code to implement functionality, and as such the code output is very ESD specific. The tool is intended for use by those who have very little to no programming experience. I would suggest that it would be far more productive for you to look at our Sample Applications and programmers guide. Thus being able to eliminate the ESD code from the equation and work directly with the Display List code to drive the FT81x.
Please take some time to look at the following examples in either Visual Studio or the FT9xx Toolchain:
https://www.ftdichip.com/Support/SoftwareExamples/FT800_Projects.htm You will also find the EVE platform guide useful:
https://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/EVE/AN_391-EVE-Platform-Guide.pdf The ESD4 functions are only available for the display aspects of the application. At the moment, you would need to edit the code after exporting it in order to pass values from other external peripherals as well.
You can use the method shown in 'Add User Functions' in the ESD user guide or just edit the code directly after export.
One example of interaction between ESD and other MCU features is the Blink LED demo provided with the ESD software. This allows the GUI created to interact with GPIO on the FT900.
Best Regards,
FTDI Community