DLPC2607: Sequence of I2c commands for configuring parallel interface source .

Venkatesan,

Thanks for your log above. I'll review it and provide feedback. In the meantime, can you share what you are using to source your video data? In addition, please share your video timing spec if available.

Best Regards,
Philippe Dollo

Hello Philippe,

Thanks for the quick response despite the holiday season! Much appreciate it!

I am rendering images stored in the flash using the Cypress Graphic engines. Basically they are all images that the graphic drivers access from the flash periodically and sends it via the RGB888 interface.

My Timing Spec is as follows :

pixelClock Freq:         -            33.33MHz

horDisplayPeriod:       -           800u (Horizontal display period - active display area)

horPulseStart:             -           832U (Horizontal sync pulse start position)

horPulseEnd               -           912U (Horizontal sync end position)

horTotal                       -          1056U (Total pixels per line)

vertDisplayPeriod       -           480U  (Vertical display period - active display area)

vertPulseStart             -           500U (Vertical sync pulse start position)

vertPulseEnd              -           512U (Vertical sync end position)

vertTotal                      -           525U (Total lines per frame)

syncPolarity                -           HSYNC_ACTIVE_LOW  |  VSYNC_ACTIVE_LOW |  DE_ACTIVE_HIGH | PIX_CLK_RIS_EDGE

Thanks & Regards,

Venkatesan S.

Venkatesan,

I noticed that your code above never re-enabled buffer swapping function at the end. It stays frozen the whole time. I suggest you start by only issuing most critical commands (source select, resolution, color space) and add additional commands once you confirm that the system is working.

Do you still encounter this problem without freeze?

Best Regards,
Philippe Dollo

Hello Philippe,

I did notice later that I forgot to unfreeze buffer, so I issued a command - (0xA3) 0x00 0x00 0x00 0x00 , at the end of the sequence to do it. But the output was still the same, blank screen.

I will also check by reordering the sequence as suggested. 

I also have a doubt in the wiring. I mapped the data, control and power lines to the DLP in the following way:

RGB888	DLP		I2C -Cyp	DLP
B0	Data_0 (45)		3V3	VINTF(3)
B1	Data_1 (46)		SCL	EXT_SCL(19)
B2	Data_2 (43 )		SDA	EXT_SDA(20)
B3	Data_3 (44)		GND	GND (1)
B4	Data_4 (41)
B5	Data_5 (42)
B6	Data_6 (39)
B7	Data_7 (40)
G0	Data_8 (37)
G1	Data_9 (39)
G2	Data_10 (36 )
G3	Data_11 (34)
G4	Data_12 (35)
G5	Data_13 (33)
G6	Data_14 (31)
G7	Data_15 (32)
R0	Data_16 (15)
R1	Data_17 (16)
R2	Data_18 (11)
R3	Data_19 (12)
R4	Data_20 (17)
R5	Data_21 (14)
R6	Data_22 (13)
R7	Data_23 (19)
RGB_CLK	PCLK (28)
HSYNC	HSYNC (29)
VSYNC	VSYNC (27)
DE	DATAEN(30)
GND	GND(45)

Are these correct? 

And what should I do with the HOST_PRESENTZ pin and the PROJ_ON_EXT pin?

Thanks and Regards,

Venkatesan S.

Venkatesan,

This pinout mapping you have chosen is actually not correct. The pinout mapping for the RGB888 video follows the same format as the one described here:
elinux.org/24bit_LCD_for_BBB

So, Data0 is actually R3, Data1 is R4, and so on. Try reconfiguring your system as such and trying again. HOST_PRESENTZ is supposed to be driven low when the DLP is connected to an external host processor, such that you can then control the system's on-off state with PROJ_ON_EXT. You should be able to leave these disconnected.

Best Regards,
Philippe Dollo

Hello Phiippe,

Happy New year!

I apologize for the delayed response. 

I tried the new pin mapping (image attached) and also reordering the commands as suggested (Source Selection ->resolution->color space -> Bus Polarity control ).  I left the HOST_PRESENTZ and PROJ_ON_EXT unconnected.

However, it still didn't work. I am just getting the default dlp intro screen.

I checked the pins with a scope and the signals seem to be properly transmitted to the dlp from the cypress board.

Should I configure any other i2c commands (like the sequence_sync mode, PDM or video frame rate) for parallel source input? 

Thanks & Regards,

Venkatesan S.

Venkatesan,

Your pin mapping setup above looks to be good. In this case, your issue is probably video output configuration. As I understand, you are still sending the same commands in sequence as listed at the top of this thread. Is that correct?

If so, what do you see when setting the system from splash screen input to parallel video input? Does the splash screen remain visible or does some kind of content appear?

In addition to the above, is it possible to generate any alternative video output specifications from your host processor? If so, you can try a native 854x480 configuration. Doing so would mean that you can minimize additional configuration steps and better isolate the problem.

Let me know about the above. Thanks for your attention.

Best Regards,
Philippe Dollo

Hello Philippe,

I had partial success by changing to native 854x480 configuration. First I'll summarize the parameters I used, just to avoid the confusion on the current system state.

The command sequence I used are as follows (in the same order):

1. Input Source Selection: Parallel source :-  0x0B 0x00 0x00 0x00 0x00

2. Input Resolution Selection - WVGA-854*480 landscape :- 0x0C 0x00 0x00 0x00 0x19

3. Output Format Selection  RGB888 :- 0x0D 0x00 0x00 0x00 0x02

4. Bus Polarity Control (VSYNC = LOW; HSYNC = LOW; DATA_EN = HIGH; PIXCLK = RIS_EDGE) :- 0xAF 0x00 0x00 0x00 0x10

5. PDM Enabled :- 0xB3 0x00 0x00 0x00 0x01

6. PDM config - PDATA and DATEN are masked and ignored when PDM :- 0xB2 0x00 0x00 0x00 0x00 

7. Video Frame Rate = 60Hz :- 0x19 0x00 0x00 0x08 0x59 

As suggested I also changed the display parameters to suit 854x480:

RESOLUTION - H: 854
RESOLUTION - V :480
PIX CLK (MHz) :30
LINE RATE (KHz): 34

I used the DLPC2607 data sheet to make sure the parameters are within specified range

Parameters -Value
tp_vsw  - 7
tp_vbp  - 28
tp_vfp  - 10
tp_tvb  - 38

tp_hsw -  24
tp_hbp  - 10
tp_hfp  - 10
tp_thh  - 20

With these values once i send the command the splash screen disappears and I get a white screen (which is the background color for my image i want to display).

However the entire image does not show up. It is as if only the top portion of the background is visible.

And if I change the images, I don't see any response from the projector.

Sometimes sporadically a red screen appears.

Maybe i need to configure some other parameter also via i2c or the display timing parameters needs to be adjusted?

Thanks & Regards,

Venkatesan S.

Venkatesan,

Did you confirm that your host processor requires some of these additional settings? For instance, you have made some configuration settings for PDM, bus polarity, etc. Have you tried testing with just the default reset values? The minimum configuration commands that you would need for a generic host processor is:

1. Input Source Selection: Parallel source :- 0x0B 0x00 0x00 0x00 0x00
2. Input Resolution Selection - WVGA-854*480 landscape :- 0x0C 0x00 0x00 0x00 0x19

If your host processor documentation gives directions on custom configuration, can you share said documentation here?

Best Regards,
Philippe Dollo