CCS Charging Experiments with ESP32

Goal

This project intends to use the ESP32-based WT32-ETH01 board together with a tpLink Homeplug modem containing an AR7420, to build the vehicle side of a CCS charging system for electrical cars.

The basis of this port is the python-variant in https://github.com/uhi22/pyPLC

News / Change history / functional status

2023-04-05 Charging loop on Alpitronics works

After fixing several topics regarding the NeighborSolicitation, the SDP succeeds, and we come to the charging loop on alpitronics hypercharger.

2023-03-25 LC Display works

The three-line-OLED display (see https://github.com/uhi22/SerialToOLED) shows the charging progress.
Simulated charging works with simulated EVSE (Win10, pyPlc).
The main crash reason was a heap leakage because receive buffer was not free'd. This is fixed.
Sporadically still crashes: panic'ed (Unhandled debug exception). Debug exception reason: Stack canary watchpoint triggered (emac_rx)

2023-03-19 PEV state machine until Charging Loop

With simulated EVSE (Win10, pyPlc) on the opposite end, the WT32-ETH01 makes the SLAC, SDP, NeighborDiscovery, TCP and the charging state machine. It runs until the charging loop. Unfortunately, the controller is not really stable. Several ethernet issues are visible:

Sometimes the eth raises ETHERNET_EVENT_DISCONNECTED.
Sporadically we get emac_esp32_transmit(229): insufficient TX buffer size
Often esp.emac: no mem for receive buffer
Sporadically a complete crash: panic'ed (Unhandled debug exception). Debug exception reason: Stack canary watchpoint triggered (emac_rx)

2023-03-11 Reading the HomePlug software versions works

Initial Arduino sketch, which is able to send and receive HomePlug messages on the Ethernet port of the WT-ETH01. Debug console is the Arduino IDE, via the RX0/TX0, which are also used for programming. As test, the sketch sends GetSoftwareVersion requests and shows the related responses on the debug console.

Benefits of this solution

much faster startup time (2s) compared to the Raspberry or Notebook
much less current consumption compared to the Raspberry or Notebook
more compact design

Drawbacks

no log file for offline analysis

Todos

[x] porting of all required homeplug stuff from python to C. [x] porting the SLAC state machine [ ] porting the Syslog message transmission [x] porting the UDP and SDP [x] integrating TCP [x] integrating the EXI decoder/encoder [x] porting the pev state machine

uhi22/ccs32