Display Update 7'' 10''

[Paul@Port]

a) Is there a partial update or fast update for the SW074AS182 or S2A20CS171?
I was looking at [TCS-P_DevelopersGuide_rF.pdf] but can only see Display Refresh which takes up to 5.3sec (depending on temperature).

I would like to display a Power Fail message on a portion of the display using a supercap to hold sufficient power, but the current*time is quite significant.
If I can update just a portion of the display with a Power Fail message then that could save time and energy.

b) If the driver IC in SW074AS182 or S2A20CS171 doesn't support this, then can I drive these displays directly from a Microchip PIC32 using its LCCG module, and thus have direct control of the display updating?

Paul

[Charming]

Dear Paul,

a) Yes, the TCM for S2A20CS171(10.2") and S1441CS121 (4.41") support partial update but the TCM of SW074AS182 hasn't supported yet due to we will release a new display instead.
You can find the demo video at the bottom of this webpage. I will have MpicoSys to join this thread and give you the support accordingly.
However, the partial update doesn't save much energy because it still updates the whole pixels of display and just the unchanged pixles to send "Nothing" data bytes.

b) Try the MpicoSys's new Gen2 TCM first. 

Charming Su @ PDi-FAE

[MichalK]

While Charming was right regarding the current consumption of the TCM Gen2 being comparable between the regular and fast updates, the fast (or "flashless") update does draw less energy because of the shorter driving time. With the 4.41" driving time at 1.3 second (room temperature), the energy consumed per each flashless update is about 24 mJ for typical image, compared to 56 mJ for a regular (or "quality") update. Also, considering your use case, you can take benefit from Gen2 functionality of partial memory update. You can store your battery low icon on a defined memory slot, and then just copy this fragment onto the framebuffer, and then display it using flashless update. I am not able to state the exact supercap capacity needed for that, but I can reveal that we have empirically tested a quality display update on a Gen2 10.2" with a 100mF cap, and it succeeded. Please take into consideration the voltage will drop along with the cap discharging, and you need to maintain at least 2.7V on the TCM during the entire process.

[Paul@Port]

That sounds good! 

a) When will the 7" Gen2 be available?
The Fast update looks like what we need.

b) Except for fast update will the interface be the same, or at least quite similar? Just wondering if we should develope our interface with the SW074AS182 we just received, or wait for Gen2?

[MichalK]

The 7.4 Gen2 release is planned for March (depending on the availability of the display panels.)
Hardware-wise the interface between the TCM and host is uniform accross all the whole family (i.e. accross both Gen1 and Gen2, and for all the display sizes.) In terms of software, the interface for 7.4 Gen2 will be compatible with Gen2 4.41 and 10.2, and backwards-compatible with all the Gen1 products.