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Tektronix TDS744 CRT to LCD color converter FPGA module DIY

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TerrySt:
Yes, the backlight intensity is just set by the DIP switch on the board I made.  I had planned on using a potentiometer to set it, but unfortunately the FPGA board I am using did not route out the input pin for the ADC channel to the low density pins.  So instead I just convert the DIP switch setting to a PWM value.

Terry

TerrySt:
Just to be clear, the DIP switches just set the backlight level.  The intensity of the traces, text and graticules is still set by the o'scope using the RGB values written to the overlay and palette registers.  I checked that the intensity adjustments from the scope work and they do.

Terry

TERRA Operative:
Nice work! 8) How do the side and bottom menus line up with the soft-buttons?

Will you open-source the design, or provide gerbers or a kit? I have a TDS784D and a TDS794D that could both get an upgrade.... :)
I wonder if making a board to do away with the dev board, if the backlight brightness could be tied in with the intensity adjustment from the scope controls?


Also, is the difference between V1 and V2 LCD panels just the interface type?

TerrySt:
I'm happy to share the design files.  I'll post the KiCad schematic and pcb files here once I check out the latest board spin.  But the pcb files might not be of use to anyone unless they also have a TDS524A since the way I made the pcb it mechanically fits the mounting points on scope and lines up with the RAMDAC chip.  I doubt any other models would share the same dimensions.
I will also post the vhdl code I that I used to convert from Vincent's code for the old version of the lcd to the new serial interface version.  And since I was doing this project mainly as a reason to learn vhdl, I re-wrote the entire code starting from scratch.  I did not use the State Machine approach that Vincent used.  I found it easier to understand that way.  I'll post that version after a bit more testing.
I don't know if there is any difference in the lcd panels between V1 and V2 other than the interface and the backlight.  The size is the same.  It fits the scope really well. Ill add a picture with the menus active.
The intensity adjustments from the scope controls are still active.  The scope adjusts the intensity of the traces and text and grid by changing the values in the palette and overlay registers.  There is no analog intensity adjustment in the scope.  So it works with the lcd just as it did with the crt.  I tested the trace and Text/Graticule intensity adjustments and they work perfectly.

The colors on the lcd are much better live.  The camera in my phone makes them look splotchy.  They are actually very solid and bright.

Terry

TERRA Operative:
Schematics would be awesome, I can lay out a version to fit my scopes, although the processor boards are reused between multiple models so it's likely your design would fit a number of different scope models.

This would mean that only a few different PCB designs would be needed to cover all models.

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