• Driving the Display

    Connor Huffine • 09/17/2020 at 19:53 • 0 comments

    The display has a main connector used to provide all of the controls. 

    The nomenclature is a bit tangled, but the basic idea is that every color (RGB) is addressed by one set of nine TLC5941 drivers. Each of those sets is clocked and blanked together, but broken into three sub-banks for data input. 

    I believe the path to effective operation is using an MCU with at least three QSPI busses. I have an ESP32-WROOM-32D breakout on hand to test with, but I'm going to make a PCB to interface with the display. 

    I'm feeling pretty positive about the way this is coming together. Using the ESP, I can set this display up to be controlled via network. The only connection needed is a power supply. 

  • Power supplies reveal the path

    Connor Huffine • 06/12/2020 at 05:05 • 0 comments

    I took a hard look at the secondary power supply, I have solved one mystery. 

    The purpose of the MOSFETs are to split the power supplies for four separate zones. I believe the intent is to multiplex the drivers by rotating the active supplies. 

    Power supplies are shared along horizontal rows, in sets of four:

    (Colors denote common power supply)

    The driver ICs have a max clock of 30MHz. Drivers are arranged into strings of three. With a length of 12b x 16 channels, the length of a string is 576b. This gives a potential max refresh rate (excluding any overhead) of 13kHz. 

  • Basic System Components

    Connor Huffine • 06/11/2020 at 18:16 • 0 comments

    TLC5941: 16 channel LED Driver

    I see 3 banks of 9, which is a bit odd. 16 channels * 3 * 9 = 432 channels, yet there are 576 LEDs. Since these LEDs are RGB, that expands to 1728 needed channels. That means I have exactly 1/4 the required control. 

    FDS6875: MOSFET

    TC1427C: MOSFET Driver

    VHCT541: Octal Buffer

    PTH05060: Power regulator (5Vin, 0.8-3.6 Vout)

    The site I bought this from claims the input voltage should be 3VDC, but the input voltage range on this piece is 4.5-5V. 

    The LEDs look similar to OSRAM MultiLEDs