Other Parts Discussed in Thread: DLPC900
According to the DLPC900 Programmer's Guide (Rev. E) Section 2.4.1.4 (DMD Idle Mode):
This mode enables a 50/50 duty cycle pattern sequence, where the entire mirror array is continuously flipped approximately every 105 μs between the on and off states. Whenever this mode is enabled, the LED Enable outputs are disabled to prevent illumination on the DMD.
I wrote a short test procedure, tracking the status and mode of the device operation after each command executed:
1. When the device is powered up, we start in the Normal mode, the sequencer is running, the default pattern is displayed in the pre-stored pattern mode:
2. Then I stop the pattern sequencer by sending the USB command 1a24 with data byte 0. The device responds as intended: no image is displayed. Only the 'dark' pattern is visible:
3. Then I enable DMDs idle mode (USB command 0201, data byte 1). At this point I expected no illumination. Instead, we got a really bright rectangle (assume, 50/50 duty cycle pattern).
The sequencer got automatically into running mode (!) and LED outputs are ON (!) which contradicts the documentation.
4. Then the DMD Idle mode was disabled. The system returned to its previous state:
Surprisingly, the sequencer got stopped automatically.
Could you please commend on such a behavior which deviates from what was cited above from the programmer's guide, that the LEDs in DMD Idle mode are not OFF, and the sequencer gets automatically launched.
Should I provide additional information, please, let me know.