Debugging Acer et241ybmi 23.8"

[danDanV1]

Specs:
-Computer: 2018 Macbook Pro 13",
-OS: Latest Mojave 10.14.4
-Monitor: Acer et241ybmi 23.8"
-Cable: USB-C to HDMI

Debug steps:
-Confirmed success with above setup with a different monitor (Phillips) I: got edid.serial: AU01821005798, I: got edid.name: PHL 246E7, therefore cable, video card, etc. should be good and issue must specific to the Acer monitor.
-DDC/CI option is set to ON via the montor's onscreen menu.

Debug version installed, response:

2019-04-10 23:28:22.222 ddcctl[5554:43158] D: NSScreen #478240582 (1920x1080 0°) 93.00 DPI
2019-04-10 23:28:22.222 ddcctl[5554:43158] I: found 1 external display
2019-04-10 23:28:22.222 ddcctl[5554:43158] I: polling display 1's EDID
2019-04-10 23:28:22.225 ddcctl[5554:43158] E: Failed to poll display!

What are the steps to debug further and determine to which extend the DDC standard is implemented?

[furudean]

I have the same issue with Acer XZ321QU.

I'm using a DP cable

2019-07-31 22:49:57.594 ddcctl[1110:12046] D: NSScreen #478276177 (2560x1440 0°) 93.00 DPI
2019-07-31 22:49:57.594 ddcctl[1110:12046] I: found 1 external display
2019-07-31 22:49:57.594 ddcctl[1110:12046] I: polling display 1's EDID
2019-07-31 22:49:57.596 ddcctl[1110:12046] E: Failed to poll display!

On line 82 of DDC.c of the current project master,

Do this:
CGDisplaySerialNumber(displayID) != (UInt32)serialNumber
Instead of:
CGDisplaySerialNumber(displayID) != serialNumber

Compile with 'make' and try it. It solved this problem for my Acer UT220hql, which now works perfectly. Tested with MacBook Pro Late 2013 over HDMI.

EDIT: Fixed line number. It's 82, not 85. Technically you'd want to do this to lines 80 and 81, as well, as the CGDisplay...Number functions return uint32_t. CFIndex, by converse, is a signed int. At least on my monitor, the MSB of the serial number is a 1, so the serial number comparison fails.

[furudean]

I'll try this when I get home! Thanks

[chrenn]

Works on my Acer PE270K. Thanks, @KNNSpeed!

[furudean]

Worked perfectly for me, thanks!!!

[danDanV1]

@kfix would you entertain a pull-request for this change? #53 (comment)

[kfix]

Absolutely entertainable @edeis53 ....

@KNNSpeed thanks for pointing out the missigning!

I'll even tag a release afterward so it can get homebrewed!