Register / Login  |  Desktop view  |  Jump to bottom of page

tcMenu Arduinio library » When using an LCD display I have noticed that the display is blank

Author: Admin
02/03/2019 10:12:12
Copied into here from an email.

I have configured up a standard LCD display over i2c using a 23017 along with a rotary encoder on the same device. Although I can print to serial the status of the menu, and the menu when debug lines are added to serial is rendering properly, the display remains blank.

Configuration:
Genuine MEGA 2560
23017 expander
20x4 display on port B
Rotary encoder and switch on port A
Using standard LCD display renderer. Configuration has been confirmed by moving the lcd initialisation into another sketch and it works there.

Author: Admin
02/03/2019 10:12:57
This is a bug that I've now reproduced on a board with similar configuration. It will be fixed in 1.2 as it is absolutely critical.

Author: Admin
03/03/2019 09:18:11
This bug will be fixed and 1.2 code base will be merged back to master later today.

It was a complex interaction. The IoAbstractionRef relies on a pointer type, for which (logically when thought about) the pointer to the object must occur before it's passed to anything.

However, if you are creating lots of global variables, and relying on ordering and initialisation, it will not always work.

It's an important point and I'll document in the IoAbstraction docs to avoid anyone else hitting this.




Register / Login  |  Desktop view  |  Jump to top of page