The component provides a general purpose connectivity engine between two micro-controllers, one acting as PPP server (slave), the other one as PPP client (host). Typical application is a WiFi connectivity provider for chips that do not have WiFi:

             SLAVE micro                                  HOST micro
    \|/  +----------------+                           +----------------+
     |   |                |          serial line      |                |
     +---+ WiFi NAT PPPoS |======== UART / SPI =======| PPPoS client   |
         |        (server)|                           |                |
         +----------------+                           +----------------+

API

Client

eppp_connect() -- Simplified API. Provides the initialization, starts the task and blocks until we're connected
eppp_client_init() -- Initialization of the client. Need to run only once.
eppp_client_start() -- Starts the connection, could be called after startup or whenever a connection is lost
eppp_client_perform() -- Perform one iteration of the PPP task (need to be called regularly in task-less configuration)

Server

eppp_listen() -- Simplified API. Provides the initialization, starts the task and blocks until the client connects
eppp_server_init() -- Initialization of the server. Need to run only once.
eppp_server_start() -- (Re)starts the connection, should be called after startup or whenever a connection is lost
eppp_server_perform() -- Perform one iteration of the PPP task (need to be called regularly in task-less configuration)

Throughput

Tested with WiFi-NAPT example, no IRAM optimizations

UART @ 3Mbauds

TCP - 2Mbits
UDP - 2Mbits

SPI @ 40MHz

TCP - 6Mbits
UDP - 10Mbits