I have a commercial LED sign that in its stock format is only controllable by IR remote (the remote is long gone). I'm trying to create a new controller for it so I can push data from one of our servers. I'd like to reuse some combination of the panels themselves, the driver boards and / or the controller. So far I'm having no luck finding good datasheets on much of anything.

What I'm looking for

  • Data on the controller and any UART connections / protocol
  • and/or
  • Info on the pinout of the 26 pin connector between the controller and LED panels
  • Info on talking to the TM1818 driver ICs on the driver board

Here's what I know about the current components

Current Controller

Model number ADSP-400NWT


I have found plenty of places to buy new ones online but no data or even a manual about it.

A 26 pin ribbon cable connects from the controller to the hub card

LED Hub card


The 26 pin ribbon cable from the controller card connects on the end connector. The next 26 pin connector goes to the first driver board

LED Driver board


I have probed around this board a bit with a multimeter looking for traces between the IDC connector and the driver ICs. I have been able to locate the CLK and LE pins, these pins on all TM1818s share a single pin in the IDC connector. Also found one SDI (data input) pin but I haven't been able to locate where the other 22 or so pins in the IDC connector (board input connector) go on the board.

Interestingly, approximately half of the IDC lines show continuity between BOTH ground and VDD

Each driver card has 8x TM1818's in 2 sets of 4


I found a little bit of data including a pinout and block diagram here http://www.datasheetspdf.com/pdf/839008/ETC/TM1818/2 but I haven't been able to locate all of the control lines in the IDC connector so there is still some buffering somewhere that I haven't traced out yet.

LED panels

The LED panels are 16 LEDs wide by 16LEDs tall, red and green. The sign has 3 identical panels.

What I'm trying to do

My goal is to interject my own controller somewhere in this path so I can drive the LED panels (ideally before the existing driver boards). I'm not worried about different brightness levels or PWM dimming (AKA high speed transfer), just want to be able to display some text being provided by one of our servers.

  • \$\begingroup\$ You should definitely try to trace out all the lines on the driver board, and then I expect you will be able to use the driver boards as is. The TM1818 looks like it's a shift register with outputs suitable for the LEDs, so you can just shift your own data in (similar to a 74HC595). You could also probe the signals coming out of the hub card without the LED drivers attached. \$\endgroup\$ – immibis Apr 27 '18 at 12:37

The TM1818 turns on and off up to 16 LEDs.

The CLK clocks the SDI (Serial Data In) into a 16 bit shift register. LE then latches the shift register outputs which drive the LEDs when OE is low.

The 8 LM1818 are daisy chained. Look at the board as a 128 bit shift register where each bit turns on of off each LED on the display.

There is a resistor connected to the R-Ext pin which sets the current to each of the 16 LEDs between 3 mA (5.1K) and 60 mA (290Ω).

All you need to do is trace the signals circled in red below (+VCC and Ground) and add your own micro-controller.

enter image description here

  • \$\begingroup\$ Only 1 SDI line appears on the 26 pin header (I understand this is correct). But if I check between SDO on the same chip and ALL the rest of the SDI ins I can't find any trace that shows continuity \$\endgroup\$ – scottinthebooth Apr 28 '18 at 22:29

Replace the control card with a DBStar HRV receiver. They have ethernet ports on them and work with the 70614 driver board. This is the one I use with RGB signs (won't support your tricolor): http://www.cnledsourcing.com/dbstar-dbshrv11s-receiving-card-p-653.html


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