General to the Cardecoder

The Cardecoder is the heart of every OpenCar-System vehicle. He is responsible for controlling all components in the vehicle. It is now available in several generations which differ significantly in size, functions. Versions 1 and 2 were available exclusively for self-construction. From version 3, the cardecoder is available as a fully assembled board in the Fichtelbahn-Shop.

Here is an overview of the Cardecoder generations:

Cardecoder V1

First generation (2012), the control was carried out exclusively by infrared signal. This version is in archive mode.
Cardecoder V2

Version 2 (2014) with stronger processor, control via infrared signal and radio possible.
Also V2 is no longer developed and is in archive mode.
Cardecoder V3

The third generation V3 (2014) is the first cardecoder to be ready in the Fichtelbahn-Shop. It is only suitable for operation with radio control. This type of data transmission works even without line of sight to the vehicle.

Cardecoder D2U (V4)

First vehicle specific version (2015), small hand-assembled series
Cardecoder V5

Cardecoder V5 available in the Fichtelbahn-Shop from QII / 2018, is an improved version of the V3. It has a current processor version, a larger number of LED outputs and has integrated the external hardware enhancements of the V3.

Data of the Cardecoder:

Operating voltage: Cardecoder V1-4: 2,4V to 4,2V (up 2 NiMh cells or 1 LiPo cell)
Cardecoder V5: 2-5V (up 2 NiMh cells or 1 LiPo/LiFePO4 cell)
LED voltage: Cardecoder V1-4: 4,3V / 80 - 350 mA (depending on input voltage and decoder version)
Cardecoder V5: 3,3V 100mA
Motor control: to 500mA, load controlled by Cardecoder V3 and 5
Battery monitoring: yes, programmable via CVs
Distance control: yes, in two steps at approx. 15 cm and approx. 5 cm (can be switched off with F3)
LED outputs: yes, with series resistor for: headlight, taillight, brake light, flashing light right + left and 5 to 8 more freely programmable e.g. blue light
Stop section: yes, input for original stop section (can be switched off with F4), recommendation IR stop section
Control: IR - DCC signal and from version V2.0.0 radio control
Programming: DCC - CV variables read and write in DCC service mode via IR - DCC signal
from version 3.0 POM CV read and write via radio signal


  • Control via normal DCC digital signal
  • Addressing with long and short DCC addresses (CV1 or CV17 / CV18)
  • Motor control with 28 and 128 speed steps
  • Front / tail light with FL (F0) switchable, brake light automatic
  • Turn signal left / right switchable with F1 / F2
  • Trailer control for lighting (with separate trailer decoder)
  • 5 (up to 17) further LED outputs with effects freely programmable and switchable with F5-F12
  • original stop section function integrated, can be switched off with F4
  • Distance control to the vehicle ahead, with F3 off
  • all LED outputs with integrated series resistors switching to GND
  • Programmable battery monitoring
  • Software update with bootloader via 2-wire connection possible
  • Vehicle type programmable (e.g., bus, emergency vehicle, garbage truck, normal car ...) different behavior of the vehicles due to the vehicle type possible

from software 03.xx.xx (05.xx.xx)

  • Radio feedback of battery level in%, speed in km / h, position report
  • Motor PID controller improved
  • improved distance control
  • improved twin stop section
  • new decoder variant for controlling a sound module with 8 additional LED outputs
  • CV list adapted to NRMA and DB decoder

from software 2.1.0

  • Feedback of battery level in%, vehicle address, current vehicle driving level (change to V2.0.0)
  • 455kHz IR control removed
  • changed distance control
  • Decoder Voltage cutoff via stop section with F7 for break in operation

from software 2.0

  • Write POM programming byte
  • alternative control via 2.4 GHz radio signal / receiver possible (instead of the 455kHz IR signal)

from software 1.2

  • Feedback of battery level in%, vehicle address, current vehicle speed in cm / second and vehicle type
  • modulated IR signal crc8 secured
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