Table of Contents
GCA_LM2 (SPL Serial Programmable Leds)
Description
This a very nice and cheap way to switch leds on and off, with a timing included in Rocrail.
Also a dedicated program is available to control the boards directly.
The board is connected to the serial (COM) port of the computer and controls 8 leds individual.
A protocol called SPL is used to control the leds, and also a special command is included to change address of this board.
The board can be connected into a chain of more than 50 boards, all with individul pre programmed address.
Supply of 5 V is needed, which should be adapted to total demand of power in the chain.
A nice supply unit for this could be GCA08-1 or GCA08-3.
Firmware
The firmware is simple and could be dveloped in basic , using PicSimulator IDE form www.oshonsoft.com.
The hardware
| The schematics | 
| The pcboard and parts positions | 
| Partslist | 
| N.B. Only complete ordered kits will be supported! | 
|---|
Connections
To give the user multiple choices of how to connect the board, there are several options.
Explanation and drawing are pending…….
The final result
A nice pc-board is available, in the same quality you are used to from GCA.
      |       | 
	
|   The white connector can be used to connect to   GCA Interfaces like GCA76, GCA77 , GCA107 etc.  |   GCA_LM2 ready for direct connection with leds   no resistors for leds needed.  | 
	
Setup & Control
Connecting Leds (how to)
Stand alone controller
A standalone control program is available from www.modeldigitaal.nl
Connection LM 2 to PC.
One of the LM2 boards should be connected to PC as follows:
|   Connector J1 or J2   GCA_LM2  |   Sub-D9   ComPort PC  | Function | 
|---|---|---|
| - (min) | 5 | Ground | 
| S | 3 | Send, Tx | 
Connection between GCA-LM2 boards
Boards could be connected from one to another by using either J1/J2 or with the use of flatcable and J5.
In case J1/J2 just use 3 wires: 
+  to +
s to s
- to -


