MTB-UNI is an universal IO module featuring 16 digital inputs and 16 digital outputs. It communicates over MTBbus (RS485). The module is designed for controlling of the model railroad accessories (such as turnouts or occupancy detectors), however is could be used generally in any other application.
This repository contains schematics & PCB layout of MTB-UNI v4 PCB. Firmware for main MCU ATmega128 is available here. More information about MTB in available here.
Schematics & PCB are designed in Eagle 9.
PCB is prepared to be automatically assembled in JLCPCB.
SMD parts on bottom side should be assembled. Each SMD part has its LCSC_ITEM
attribute set.
- Input voltage: 7–17 V. Protection: when > 18 V is applied, input is shorted. Afterwards, current is limited by PTC fuse on input to 200 mA. Changed-polarity protection.
- Max current consumption: 120 mA.
- Outputs: 16 open collectors. Max current: 200 mA / pin. 500 mA per 8 pins. Active-low. Pull-up should be in receiving device.
- Inputs: 16 active-low digital inputs. Pulled up to +5 V internally. Max 5.1 V on input. When bigger voltage applied, input is shorted, current is limited to 50 mA by PTC fuse.
- ULN modules & RS485 drivers are in DIL packages & sockets, so they could be easily replaced in case of failure.
- Screw sockets or connectors could be variably assembled on inputs & outputs based on user requirements.
MTB-UNI v4 module is designed by:
- Laboratory of railroad control Mendel University Brno,
- Model Railway Club Brno.
People:
- Jan Horáček
- Robert Čížek
Content of the repository is provided under Creative Commons Attribution-ShareAlike 4.0 License as openhardware project. You may download any data, contribute to the project, create PCB yourself or even sell it yourself.