Sharp Memory LCD Displays = Ultra Low Power


#81

@RWB did you use that board or a different one?


#82

@dplumly I used the 1.33 & 2.7 inch screens with the Adafruit breakout board that you have.

I can guarantee you that the 4.4 inch screen will also work.

Did you change the pixel dimension size in this part of the .H file:

I was able to run the 4" display using the Adafruit code on the Teensy 3.1 which I used because it has tons of extra memory.


#83

@RWB, @dplumly the the 2.7" display, at 400x240, requires a 12KB RAM buffer. The 4.4" display, at 320x240 requires a 9.6KB RAM buffer. Both of these will fit in the Photon. :smile:


#84

@peekay123 I haven’t tried the 2.7" screen on the Photon yet.

So is all that needs changed the width and height settings in the .H file?


#85

@RWB, yup! I need to get another driver board cause changing the displays is going to damage them for sure.


#86

@RWB @peekay123 I did change the pixel dimensions in the .h to 320 x 240. The most I have gotten out of the 4.4in screen has been little dots or bars, but no actual image in the startup sequence. I did add a line of code I saw that @peekay123 posted on another forum because the Photon would breathing green after a second.

SYSTEM_THREAD(ENABLED)

That worked for the breathing green problem, but not on the 4.4 screen. I got it to work on an Arduino, but without changing the screen size due to ram.

But that’s fine, just shows the screen actually works even though the ribbon is temperamental. I can get the 96 x 96 to work with the Photon, but still no images on the 4.4 inch.

Here are the lines on the 4.4 inch

Any thoughts?


#87

@dplumly, remind me which library (link please) you are using and what is your wiring?


#88

I am using yours from Github I pulled a while back.

Photon:
VIN
GND
A3
A5
A1

Adafruit Breakout:
VIN
GND
CLK
DI
CS

Have the pins changed from the Core to the Photon?


#89

@dplumly I can try this also since I have a 4" screen here also. Just going to need a second to get it setup.

I’m using pins A2, A3, and A5 using @peekay123 code to run a 1.33 inch screen now. I see your Photon wiring is different.


#90

@dplumly, wiring looks correct. Did you change the height and width values in Adafruit_SharpMem.h?

#define SHARPMEM_LCDWIDTH       	(320)
#define SHARPMEM_LCDHEIGHT      	(240)

#91

@RWB, the only difference is that @dplumly is using A1 for SS, not A2. I don’t have the 4.4" display but I do have the 2.7" at home I can test later.


#92

@dplumly Will any part of the demo code work? right? Is it just he graphics that don’t display properly?


#93

@peekay123 yes I did change the values in the Adafruit_SharpMem.h to 320 x 240.


#94

@RWB I can’t get any part of the demo to show up. The only thing that shows up is random dots. Sometimes heavy and sometimes the inverse. Or it is random bars of black.

It’s either something like this or just a blank screen.


#95

@dplumly I’ll try the same as you just going to need a second to set it up during a break.


#96

Sounds good @RWB!


#97

@dplumly, @RWB, I got the 2.7" 400x240 running just fine on the Photon. HOWEVER, I needed to fix a couple of things. First, the SPI_clock_divider needed to be set to SPI_CLOCK_DIV16 otherwise the SPI was too fast and garbage was displayed. Second, in the demo app, any variable relating to display width had to change from a uint8_t or int8_t to a uint16_t or int16_t to handle the large display width.


#98

@peekay123 If you let me know where to find your updated code I’ll try the 4" screen real quick.

And Awesome that you have that all fixed up now!


#99

@RWB, I did not post any updated code. In fact, my github repo has the correct SPI divider setting but just needs the fixes in the testdrawline() function.


#100

@RWB, based on everything I learned with the color Sharpmem display, I will be updating the monochrome display library. I also want to make display selection easier with simpler #defines instead of having to specify display width and height.

BTW, any news from Sharp?