I want to make this working now.
A 768 LEDs matrix!
I use 6x multiplex and serial buffers.
To save a little space, 4x 74hc164 are used for 32 LEDs each, and 1x 74hc595 to drive MOSFET sinks.
4x 16f1824 controllers are used because I want to implement 16 brightness levels for each LEDs.
1x PIC32 is used to generate the bitmaps. It is not even wired up yet.
I did not draw a schematic...
So it is a bit messy to complete the circuit. I figured out some connections are left out for the 3rd panel, for instance between the serial buffers. The MOSFETs are not wired as well.
Recently I fixed some broken LEDs for the first two panels.
All 4 controllers are flashed with a test firmware. I have not yet debugged the brightness control, only worked out the bitmap pattern.
Each data line has a 22uH damping coil at it's end- otherwise the data does not arrive (I use full speed).
Maybe I publish the firmware for you to examine and to help out. It does not look so nice.
Power supply is 3.3V from a 12V electronic transformer, so I don't need 128 LED resistors. Made a big cooler for the LM2576 chip but right now it is not really neccessary.
This was some months ago, rather complicate way of mounting. It is glued with epoxy on the bottom of the VGA cooler and mounted upside down.
A 768 LEDs matrix!
I use 6x multiplex and serial buffers.
To save a little space, 4x 74hc164 are used for 32 LEDs each, and 1x 74hc595 to drive MOSFET sinks.
4x 16f1824 controllers are used because I want to implement 16 brightness levels for each LEDs.
1x PIC32 is used to generate the bitmaps. It is not even wired up yet.
I did not draw a schematic...
So it is a bit messy to complete the circuit. I figured out some connections are left out for the 3rd panel, for instance between the serial buffers. The MOSFETs are not wired as well.
Recently I fixed some broken LEDs for the first two panels.
All 4 controllers are flashed with a test firmware. I have not yet debugged the brightness control, only worked out the bitmap pattern.
Each data line has a 22uH damping coil at it's end- otherwise the data does not arrive (I use full speed).
Maybe I publish the firmware for you to examine and to help out. It does not look so nice.
Power supply is 3.3V from a 12V electronic transformer, so I don't need 128 LED resistors. Made a big cooler for the LM2576 chip but right now it is not really neccessary.
This was some months ago, rather complicate way of mounting. It is glued with epoxy on the bottom of the VGA cooler and mounted upside down.
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