the actual low level communication (i.e. the Control Pilot signal with states A-F and the PWM) is usually handled in a microcontroller in most charger architectures for electrical safety reasons. To connect such a control pilot board to EVerest a driver is needed that implements the board_support_AC interface (DC is not fully implemented, once done this interface will be renamed). 

An example of such a HW driver is in YetiDriver. The driver module is then used by the EvseManager, which is the central module managing the charging session and the coordination between high level and low level communication.

See attached PDF on how the communication between the EvseManager and the HW driver works.

For high level comms (ISO15118) for AC and DC the EvseManager uses an additional slac (e.g. implemented in EvseSlac) module and an ISO15118_charger interface for the HLC (e.g. implemented in JsRiseV2G). 

In principle it would be easy to write a board_support_driver that e.g. uses a local GPIO for CP output and ADCs, there is some example code in the PDF as well.

Best,

Cornelius