Foto cFos Power Brain

cFos Charging Controller
The EVSE Controller

The cFos Power Brain Controller is a controller for installation in a wall box for charging electric cars according to IEC 62196 (Type 2). For this purpose, the cFos Power Brain Controller monitors the "Charge Pilot" (CP) and "Proximity Pilot" (PP) signals of the connection cable to the wallbox. A resistance in the cable signals via PP the maximum charging current for which the cable is designed. CP is used to detect the car, monitor short circuits and signal the maximum charging current using PWM.

The cFos Power Brain Controller has the following components:

  • 230V relay for switching a 3-phase contactor to release the charging current
  • optional connection of a DC residual current sensor from Western Automation
  • RS 485 interface
  • I2C interface for connection of displays and RFID readers (1)
  • 2 S0 inputs, potential-free (2)
  • GPIO Pinheader with numerous analog and digital inputs and outputs
  • 230V integrated power supply
Schematics of the cFos Charging Controller input/output connectors
Schematics of the cFos Power Brain Controller input/output connectors

The heart of the cFos Power Brain Controller is an ESP32 from Espressif Systems. With the help of this powerful microcontroller, the cFos Power Brain Controller can speak the following communication protocols:

  • WiFi 802.11 b/g/n, including full TCP/IP stack
  • OCPP 1.5 and OCPP 1.6 (SOAP and JSON), both client and backend
  • HTTP 1.1
  • Modbus TCP and RTU

You can therefore use cFos Power Brain Controller to build a EVSE that speaks OCPP and Modbus at the same time and can also be controlled via an HTTP API. Such EVSEs can then be easily networked via WiFi

The cFos Power Brain Controller can read meters via Modbus, eg the ABB B23 112-100 (but also others according to your wishes) or up to two S0 meters via the S0 inputs. This means that the Wallbox can be inexpensively equipped with an intermediate meter for billing purposes and at the same time optionally read other meters from consumers or producers (solar system).

Of course our own EVSE uses the cFos Power Brain Controller.

Questions and Answers regarding cFos Power Brain Wallbox, cFos Power Brain Controller and cFos Charging Manager

Further features

  • Simultaneous operation as access point and as WiFi station (i.e. logged into the local WLAN router)
  • Firmware update via WLAN
  • Modbus RTU/TCP Proxy
  • Operation as charging manager.
    Full functionality, like the cFos Charging Manager.
    At least 10 additional EVSEs can be controlled.
  • Integrated WLAN access point
  • Connection of display and RFID reader (1)

(1) Only for devices supported by the cFos Power Brain Controller, ie only for controllers installed in large numbers in EVSEs from OEM partners. Only the scope of equipment described there applies tothe cFos Power Brain Wallbox.
(2) The inputs can be controlled potential-free. Voltage from approx. 3.3V to 24V. The cFos Power Brain Controller can optionally supply 12V voltage.


EU Declaration of Conformity

Download EU Declaration of Conformity (JPG) for cFos Power Brain Controller

WEEE registration number according to the Electrical and Electronic Equipment Directive (ElektroG): DE 30077948