nanoDLP

hey thanks for your reply
i sent a post to the ti community. but ill post it here also:

hello
im trying to build a DLP 3dPrinter using the DLP4500 EVM and the opensource nanoDLP host + marlin firmware(for the arduino)

when im connecting the system to my computer (HDMI+USB), i get in to video mode in the LightCrafter Gui
and i can see the projector is projecting my desktop. so far all good.

now, when im unplugging the HDMI and connect it to the RaspberryPi3, i get a blue screen that does not change
if i send something to print, the printer is moving, and i can see nanoDLP host is sending images to the projector
but the light that projects is only a blue square.

so i did some checks and configured some stuff in the RPI3 boot (config.txt)
and now when use the terminal to get some info on the video configurations of the rpi3 and what is connected to him i get the following results:

when i type: /opt/vc/bin/tvservice -m DMT
i get a list of available modes
mode 4: 640x480 @ 60Hz 4:3 clock25MHz progressive
mode 28: 1280x800 @ 60Hz 16:10, clock:83MHz progressive

and when i type: /opt/vc/bin/tvservice -s
i get my current state
state 0x120006 [DVI DMT (28) RGB full 16:10], 1280x800 @ 60.00Hz, progressive

looks good to me as far as i understand

so the projector itself is working, and i think the video config of the raspberry pi3 is fine(i think im not sure!!!)
so the last thing that can influance this is the projector configuration inside the nanoDLP HOST, i will share them here and please help me to figure out if i configured something wrong

Projector Resolution Width: 1280
Projector Resolution Height: 800
Projector communication Type:(USB / Serial - ASCII (\r\n)
                                Communicate in ASCII mode and end commands with carriage return + new line
                              USB / Serial - ASCII (\r)
                                Communicate in ASCII mode and end commands with carriage return
                              USB / Serial - ASCII (\n)
                                Communicate in ASCII mode and end commands with new line
                              USB / Serial - Binary
                                Communicate in Binary mode
                              HDMI Power On/Off
                                Force the projector into standby mode by cutting the signal to the projector
                              Execution Only
                                Run external syscall only - Useful to control the projector through HDMI-CEC)
****what should be the communication type? the projector is plugged in to te RPI3 through the HDMI and to the COMPUTER through the USB****
Baud Rate: 115200
USB/Serial Port Adress: /dev/ttyUSB1
Projector Turn On Command: \x06\x14\x00\x04\x00\x34\x11\x00\x00\x5D
Projector Turn Off Command:\x06\x14\x00\x04\x00\x34\x11\x01\x00\x5E
Display Display Number: 0
Execute to Turn Projector On:\x06\x14\x00\x04\x00\x34\x11\x00\x00\x5D
Execute to Turn Projector Off:\x06\x14\x00\x04\x00\x34\x11\x01\x00\x5E

if some additional information is required please tell me!!

10q very much for your help
i feel really dumb, but the hdmi cable was "broken" errrr
all good now 

but still i would like to see your rpi config

are you also using a dmd mirror array?