The CTC-Locomotive Module-21mtc is only useful for locomotives with Märklin’s 21mtc interface. Due to the standardised plug, this locomotive module can be installed without soldering. For older locomotives, there are various adapter boards on the market with larger solder pads or cables.
| Property | Description |
|---|---|
| Optimized for | Locomotives with Märklin 21mtc interface |
| Dimensions | 30 x 15.5 mm |
| Processor | Espressif ESP32 |
| Input voltage | approx. 9 V to 24 V DC or digital power or AC (with support capacitor) |
| Motor output | 1x DC motor: continuous current 1.0 A, Peak 2.8 A |
| Switch outputs | 6x 500 mA LowSide (F0L, F0R, AUX1 to AUX 4) 2x Digital (AUX5, AUX6) |
| Current max. sum | 2 A |
| Interfaces | CTC-IR-receiver, Trainbus (e.g. as I2C), 2x Servo, 2x Input |
| Passive online current | TBD |
| Boot current | 50 mA at 15 V |
In the overview “CTC-Locomotive modules” you can find further modules and links to installation instructions.
Pin Assignment
Details about pin assignment and dimensions can be found in the RailCommunity Standard RCN-121.
The image still shows the first version:
Connection
Notes:
- When choosing the input voltage, please make sure that the motors, lamps, etc. connected to the CTC module can also withstand this voltage!
- The train bus is not supported by the current firmware.
- When soldering cables for the buffer capacitor, make sure that the plugging of the 21mtc socket is not hindered.
To connect:
- plug the CTC module onto the 22-pin 21mtc connector.
- plug the optional CTC IR receiver into the 10-pin socket on the CTC module (red marking points towards the center of the board).
The assignment of light and AUX ports to switches in the app can be freely configured (Cfg.xml).
Additional Connections
- Two more switching outputs with a max of 500 mA are available under ExtOut-1 and ExtOut-2.
- Two digital inputs are available under Input-1 and Input-2
IR Receiver
We provide you with a cable with the matching 10-pin connector for the IR receiver. Installed in a Märklin locomotive BR 247 (#36292), it looks like this:
