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