WiCAN ESPHome Configuration (work in progress, abbreviated)

esphome.yaml

# Be warned: This is just a first try and still very much work in progress - no guarantees given whatsoever!
#
# To install the ESPHome firmware on the WiCAN for the first time (before being able to use ESPHome OTA), I built the firmware
# for download (in "modern" format) and then used the following command line on Linux:
# esptool.py --before=default_reset --after=hard_reset --no-stub write_flash --flash_mode dio --flash_freq 80m --flash_size 4MB 0x0 /home/.../Downloads/m-wican-factory.bin
#
# Don't forget to short the pins to enable boot mode (https://github.com/meatpiHQ/wican-fw#obd).
#
# Using the graphical tool (https://github.com/meatpiHQ/wican-fw#2-usb-flash) will probably work just as well. Just populate
# the first item in the list with 0x0 and /home/.../Downloads/m-wican-factory.bin and leave the rest empty.
#
# Thereafter I just used the ESPHome OTA feature - but be aware that WiFi must be turned on for this to work, i.e. the power
# safe mode (see below) must be off.

substitutions:
  device_name: m-eup-wican

esp32:
  variant: ESP32C3
  board: esp32-c3-devkitm-1

esphome:
  name: ${device_name}

logger:

api:

time:
  platform: homeassistant

web_server:
  version: 2
  ota: false
  include_internal: true

wifi:
  # your details here

ota:
  password: # your details here


packages:

  leds:

    output:

      - id: blue_led_output
        platform: gpio
        pin: 7

      - id: green_led_output
        platform: gpio
        pin: {number: 8, inverted: true}

      - id: yellow_led_output
        platform: gpio
        pin: {number: 9, inverted: true}


    light:

      - platform: binary
        id: blue_led
        output: blue_led_output

      - platform: binary
        id: green_led
        output: green_led_output

      - platform: binary
        id: yellow_led
        output: yellow_led_output


  can:

    canbus:

      - platform: esp32_can
        tx_pin: 0
        rx_pin: 3
        bit_rate: 500kbps
        can_id: 0 # mandatory but we do not use it
        on_frame:
          # dump all frames to log
          - can_id: 0
            can_id_mask: 0
            then:
              - lambda: |-
                  auto data_pretty = remote_transmission_request ? "n/a" : format_hex_pretty(x).c_str();
                  ESP_LOGD("eup_dump", "can_id: 0x%08x, rtr: %d, length: %d, content: %s", can_id, remote_transmission_request, x.size(), data_pretty);
          # first byte: real data length
          - can_id: 0x7ED # VWUP_BAT_MGMT_RX
            then:
              - lambda: |-
                  // VW e-Up absolute SOC from Battery Management (available during "vehicle on" and "vehicle charging")
                  if (x.size() >= 5 && x[0] >= 4 && x[1] == 98 && x[2] == 0x02 && x[3] == 0x8C) // VWUP_BAT_MGMT_SOC_ABS
                    // https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/blob/9ddbb0182158d8d7d4afe03dce61afb2ec856787/vehicle/OVMS.V3/components/vehicle_vweup/src/vweup_obd.cpp#L850
                    id(car_soc).publish_state(round(2.0f * x[4] * 100 / 250) / 2.0f); // round to 0.5 %

    switch:

      - platform: gpio
        id: can_enabled
        pin:
          number: 6
          inverted: true
        restore_mode: ALWAYS_ON
        # TBD: disabling CAN seems to disturb the driver badly and it will not work again after enabling again but only after reboot
        # on_turn_on:
        #   - lambda: twai_start();
        # on_turn_off:
        #   - lambda: twai_stop(); # keep driver error counter low

    script:

      # Poll PIDs
      # first byte: data length
      # second byte 0x22: VEHICLE_POLL_TYPE_READDATA / ReadDataByIdentifier (16 bit PID)
      # needs to be filled up with 0xAA to be accepted by the control units
      - id: query_soc_script
        then:
          - if:
              condition: {switch.is_on: can_enabled}
              then:
                # VW e-Up SOC from Battery Management (available during "vehicle on" and "vehicle charging")
                # based on https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/blob/9ddbb0182158d8d7d4afe03dce61afb2ec856787/vehicle/OVMS.V3/components/vehicle_vweup/src/vweup_obd.cpp#L67
                # also see "xvu.b.soc" here: https://docs.openvehicles.com/en/latest/components/vehicle_vweup/docs/index_obd.html#custom-metrics
                - canbus.send:
                    can_id: 0x7E5 # VWUP_BAT_MGMT_TX
                    data: [ 3, 0x22, 0x02, 0x8C, 0xAA, 0xAA, 0xAA, 0xAA ] # VWUP_BAT_MGMT_SOC_ABS

    interval:
      - interval: 1min
        then:
          - script.execute: query_soc_script

    sensor:

      - platform: template
        id: car_soc
        name: '${device_name} car_soc'
        unit_of_measurement: '%'
        accuracy_decimals: 1
        device_class: battery
        state_class: measurement


  power_safe_mode:

    sensor:

      - platform: adc
        id: starter_battery_voltage
        name: '${device_name} starter_battery_voltage'
        pin: 4
        attenuation: 11db # https://github.com/meatpiHQ/wican-fw/blob/bf212132f8e506f2c520e917daf86e53a1070302/main/sleep_mode.c#L234
        filters:
          - lambda: return x * 116 / 16; # https://github.com/meatpiHQ/wican-fw/blob/bf212132f8e506f2c520e917daf86e53a1070302/main/sleep_mode.c#L397
        update_interval: 5s
        unit_of_measurement: V
        accuracy_decimals: 1
        device_class: voltage
        state_class: measurement

    binary_sensor:

      - platform: template
        id: car_is_on
        name: '${device_name} car_is_on'
        lambda: return id(starter_battery_voltage).state >= 12.9;
        # did not find any other way to realize different timeouts for on and off :-(
        # neither delay_on and delay_off nor on_state with delays based on state did work reliably
        on_state:
          - script.execute: power_safe_mode_script

    script:

      - id: power_safe_mode_script
        mode: restart # important, otherwise delays will not cancel each other
        then:
          - if:
              condition: {binary_sensor.is_on: car_is_on}
              then:
                - delay: 10sec
                - switch.turn_off: power_safe_mode
              else:
                - delay: 3min
                - switch.turn_on: power_safe_mode

    switch:

      - platform: template
        id: power_safe_mode
        name: '${device_name} power_safe_mode'
        optimistic: true
        restore_mode: ALWAYS_OFF
        on_turn_on:
          - logger.log: "Power Safe Mode: ON"
          - delay: 3sec # allow to send the latest state to HA before disconnecting wifi
          # - switch.turn_off: can_enabled
          - wifi.disable:
        on_turn_off:
          - logger.log: "Power Safe Mode: OFF"
          - wifi.enable:
          # - switch.turn_on: can_enabled
          - delay: 10sec
          - script.execute: query_soc_script


    api:
      # Required for wifi.disable to not trigger a reboot. We probably need to keep an eye on this to ensure that it really
      # is not required. A potential workaround could be to just trigger a reboot when resuming from power safe mode.
      # This would also have the advantage of not having to disable and again re-enable the CAN bus for sleeping.
      reboot_timeout: 0s

@jaripetteri I added some comments in the gist above and switched some values to hex - this way it should be more obvious where the constants etc. come from.