MattzoBricks

Intelligent LEGO trains

MLC mega

The MLC mega is a magnificent version of the MattzoLayoutController that can be used to control 16 servos, 8 light signals and 16 sensors at the same time.

It can also be configured to work as a controller for level crossings, bascule bridges and turn tables.

MLC mega
MLC mega

The controller has one built-in PCA9685 servo port extender and two built-in MCP23017 I/O port extenders. The case has a lateral dimension of 10×10 studs (8 x 8 cm) and is 5 bricks high (4,8 cm).

MLC mega
MLC mega

The case uses especially designed PCBs and comes with a case that can be easily created with a 3D printer.

Building Instructions

Instructions (in German), Gerber files for the PCBs and STL files for the case and other parts can be downloaded here.

We have ordered the PCBs at https://jlcpcb.com/

Find information how to buy the other required material on the bill of material.

The following pictures illustrate the building procedure step-by-step for the power supply option no. 3:

First solder the ESP8266 on the lower PCB
Then solder the power plug on the PCB
You need some more solder because of the relatively large gap
Install two 10k resistors
Add the AMS1117
Create a galvanic connection between IN+ and OUT+
Install the connector next to the microcontroller. This will provide the connection to the upper board later
Solder 32 120 Ohm resistors onto the upper PCB
Add the two MCP23017s and the connectors for the sensors and signals
Solder two capacitators next to the MCP23017
From the PCA9685, you need to remove the two elements marked with the red box
Solder a new capacitator on the other side of the PCA9685. Watch the correct orientation of the component. Mount the holders
Solder a cable onto the PCA9685 and lead it as shown to the backside of the port extender
prepare the cable on the other end
Crimp some connectors on it and solder them onto the upper PCB
Mount the lower PCB and the PCA9685 into the case
Place a second connector (red box) onto the first one
Mount the upper PCB, place single connector pins into the correct holes to establlish the connection to the lower board

We are presently preparing an improved version of the MLC mega that will likely be a big smaller and easier to build.

Other MattzoLayoutControllers

The MLC mega is not alone. It has a small brother, called MLC mini, which is a bit smaller and easier to build.

MLC mega and mini
MLC mega and mini

3 thoughts on “MLC mega”

  1. The way the cables are soldered to the PCA9685 makes fitting the top board more complicated than necessary. I recommend desoldering the connectors on that side and soldering the wires on the other side of the PCA9685. Soldering the cables on the other side provides more wiggle room to fit the board.

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