fix(tesla_wall_connector): no charge power through an open contactor (0.1.2)

CHANGELOG.md

@@ -2,6 +2,27 @@
 
 ## [Unreleased]
 
+### tesla_wall_connector 0.1.2
+
+An idle Wall Connector no longer shows charge power. With no car on the
+cable and the contactor open, the unit reads 0 V on its output legs and
+about 0.5–1 A of sensor offset. The leg sum was 0, so the driver fell back to
+`grid_v × vehicle_current_a`: the voltage on the grid side of the open
+contactor times the offset. One field report showed 184 W, and 284 W in the
+flow diagram, with no car present. That fallback is the only path in 0.1.1
+that gives power with every leg at 0 V.
+
+- Charge power and `charging` now need a closed contactor. A reply without
+  `contactor_closed` falls back to `vehicle_connected` and then the EVSE
+  charging states.
+- The `grid_v` fallback now runs only when the reply has no leg voltage at
+  all. A leg that reads 0 V carries no power.
+- Split-phase installs and measured leg power through a closed contactor do
+  not change.
+
+FTW's bundled copy does not move with this commit. Bump the pin and run
+`scripts/sync-bundled-drivers.sh`.
+
 ### sungrow 1.6.1
 
 An inverter that drops off the network no longer loses registers or its

SUPPORT_STATUS.md

@@ -164,8 +164,8 @@ Catalog source is not proof that a target can install or run a driver.
 | tesla_cloud | 0.2.0 | blixt-l1 | not_assessed | — | not_recorded | not_assessed |
 | tesla_vehicle | 0.2.6 | ftw-core | not_assessed | — | not_recorded | not_assessed |
 | tesla_vehicle | 0.2.6 | blixt-l1 | not_assessed | — | not_recorded | not_assessed |
-| tesla_wall_connector | 0.1.1 | ftw-core | not_assessed | — | not_recorded | not_assessed |
-| tesla_wall_connector | 0.1.1 | blixt-l1 | not_assessed | — | not_recorded | not_assessed |
+| tesla_wall_connector | 0.1.2 | ftw-core | not_assessed | — | not_recorded | not_assessed |
+| tesla_wall_connector | 0.1.2 | blixt-l1 | not_assessed | — | not_recorded | not_assessed |
 | teslamate_vehicle | 0.2.0 | ftw-core | not_assessed | — | not_recorded | not_assessed |
 | teslamate_vehicle | 0.2.0 | blixt-l1 | not_assessed | — | not_recorded | not_assessed |
 | tibber | 1.1.2 | ftw-core | not_assessed | — | not_recorded | not_assessed |

devices.yaml

@@ -1852,7 +1852,7 @@ manufacturers:
         protocols:
           - protocol: http
             driver: "tesla_wall_connector"
-            version: "0.1.1"
+            version: "0.1.2"
             ders: [ev]
             control: false
         firmware_versions: ""

drivers/lua/tesla_wall_connector.lua

@@ -26,7 +26,7 @@ DRIVER = {
   id           = "tesla_wall_connector",
   name         = "Tesla Wall Connector",
   manufacturer = "Tesla",
-  version      = "0.1.1",
+  version      = "0.1.2",
   protocols    = { "http" },
   capabilities = { "ev" },
   read_only    = true,
@@ -131,20 +131,31 @@ local function phase_power(v, a)
   return v * a
 end
 
-local function charge_power(vitals)
-  if split_phase then
-    local w = (as_number(vitals.grid_v) or 0) * (as_number(vitals.vehicle_current_a) or 0)
-    if w < 0 then w = 0 end
-    return w
+-- The contactor joins the car to the grid and closes only with a car on
+-- the cable. While it is open no current reaches a car: an idle unit still
+-- reads about 0.5–1 A of sensor offset on its legs, and that is not load.
+-- A reply without contactor_closed falls back to vehicle_connected and
+-- the EVSE state.
+local function contactor_closed(state, vitals)
+  if vitals.contactor_closed ~= nil then return vitals.contactor_closed == true end
+  if vitals.vehicle_connected == false then return false end
+  return state == EVSE_CHARGE_LOW or state == EVSE_CHARGE_FULL
+end
+
+local function charge_power(state, vitals)
+  if not contactor_closed(state, vitals) then return 0 end
+  local grid_w = (as_number(vitals.grid_v) or 0) * (as_number(vitals.vehicle_current_a) or 0)
+  if grid_w < 0 then grid_w = 0 end
+  if split_phase then return grid_w end
+  -- The legs are measured on the car side of the contactor. Only a reply
+  -- with no leg voltage at all falls back to the grid voltage; a leg that
+  -- reads 0 V carries no power.
+  if vitals.voltageA_v == nil and vitals.voltageB_v == nil and vitals.voltageC_v == nil then
+    return grid_w
   end
-  local w = phase_power(vitals.voltageA_v, vitals.currentA_a)
+  return phase_power(vitals.voltageA_v, vitals.currentA_a)
     + phase_power(vitals.voltageB_v, vitals.currentB_a)
     + phase_power(vitals.voltageC_v, vitals.currentC_a)
-  if w <= 0 then
-    local fallback = (as_number(vitals.grid_v) or 0) * (as_number(vitals.vehicle_current_a) or 0)
-    if fallback > 0 then w = fallback end
-  end
-  return w
 end
 
 local function active_phases(vitals)
@@ -156,16 +167,11 @@ local function active_phases(vitals)
   return n
 end
 
-local function is_charging(state, vitals)
-  if state == EVSE_CHARGE_LOW or state == EVSE_CHARGE_FULL then return true end
-  return vitals.contactor_closed == true
-end
-
 local function is_connected(state, vitals)
   if vitals.vehicle_connected == true then return true end
   return state == EVSE_CONNECTED or state == EVSE_READY
     or state == EVSE_HANDSHAKE or state == EVSE_FINISHED
-    or state == EVSE_WAIT_CAR or is_charging(state, vitals)
+    or state == EVSE_WAIT_CAR or contactor_closed(state, vitals)
 end
 
 function driver_init(config)
@@ -209,10 +215,10 @@ function driver_poll()
   end
 
   local state = as_number(vitals.evse_state) or EVSE_IDLE
-  local power_w = charge_power(vitals)
+  local power_w = charge_power(state, vitals)
   local session_wh = as_number(vitals.session_energy_wh) or 0
   local connected = is_connected(state, vitals)
-  local charging = is_charging(state, vitals)
+  local charging = contactor_closed(state, vitals)
   local phases = active_phases(vitals)
 
   host.emit("ev", {

drivers/tests/lua_harness/test_tesla_wall_connector.lua

@@ -0,0 +1,130 @@
+-- Tesla Wall Connector Gen 3: charge power comes only through a closed
+-- contactor with a car on the cable, from measured volts and amps.
+dofile("drivers/tests/lua_harness/host_mock.lua")
+
+local BASE = "http://wc.test"
+
+local function poll(vitals, config)
+  host.reset()
+  host._http_responses[BASE .. "/api/1/version"] =
+    '{"serial_number":"TWC-SN-1","part_number":"1529455-02-J","firmware_version":"24.36.3"}'
+  host._http_responses[BASE .. "/api/1/vitals"] = vitals
+  dofile("drivers/lua/tesla_wall_connector.lua")
+  config = config or {}
+  config.base_url = BASE
+  driver_init(config)
+  assert(driver_poll() == 5000)
+  local ev = host._emitted.ev
+  assert(ev and #ev == 1, "one ev reading per poll")
+  return ev[1]
+end
+
+local function near(got, want, tol, label)
+  assert(math.abs(got - want) <= tol,
+    string.format("%s: got %.1f W, want %.1f W", label, got, want))
+end
+
+-- A real idle unit: no car, contactor open, 0 V on every output leg, and
+-- 0.8 A and 0.6 A of sensor offset on legs A and B. The connection test
+-- read EV 184 W, which is grid_v × vehicle_current_a (230 V × 0.8 A).
+-- The report did not show those two fields; these are the values that
+-- give 184 W.
+local idle = [[{"contactor_closed":false,"vehicle_connected":false,"session_s":0,
+"grid_v":230.0,"grid_hz":50.01,"vehicle_current_a":0.8,
+"currentA_a":0.8,"currentB_a":0.6,"currentC_a":0.0,"currentN_a":0.0,
+"voltageA_v":0.0,"voltageB_v":0.0,"voltageC_v":0.0,
+"relay_coil_v":11.9,"pcba_temp_c":21.3,"handle_temp_c":14.2,"mcu_temp_c":27.5,
+"uptime_s":86400,"input_thermopile_uv":-210,"prox_v":0.0,
+"pilot_high_v":11.9,"pilot_low_v":11.9,"session_energy_wh":0.0,
+"config_status":5,"evse_state":1,"current_alerts":[]}]]
+local r = poll(idle)
+assert(r.w == 0, "idle unit with open contactor reported " .. tostring(r.w) .. " W")
+assert(r.connected == false and r.charging == false)
+assert(host._metrics.ev_power_w.value == 0, "ev_power_w must match w")
+-- The raw sensor reading stays visible as a diagnostic.
+assert(host._metrics.ev_l1_a.value == 0.8 and host._metrics.ev_l1_v.value == 0)
+
+-- A larger offset sample is still no load. The same report's flow
+-- diagram showed 284 W; 1.2 A × 236.7 V is one pair that gives it.
+r = poll((idle:gsub('"vehicle_current_a":0.8', '"vehicle_current_a":1.2')
+  :gsub('"grid_v":230.0', '"grid_v":236.7')))
+assert(r.w == 0, "offset sample reported " .. tostring(r.w) .. " W")
+
+-- A reply without contactor_closed: no car means no charge power.
+r = poll('{"vehicle_connected":false,"evse_state":1,"grid_v":230,"vehicle_current_a":0.8,'
+  .. '"currentA_a":0.8,"currentB_a":0.6,"voltageA_v":0,"voltageB_v":0,"voltageC_v":0}')
+assert(r.w == 0 and r.charging == false)
+
+-- Car on the cable, contactor open (waiting or finished): still no load.
+r = poll((idle:gsub('"vehicle_connected":false', '"vehicle_connected":true')
+  :gsub('"evse_state":1', '"evse_state":9')))
+assert(r.w == 0, "open contactor with car reported " .. tostring(r.w) .. " W")
+assert(r.connected == true and r.charging == false)
+
+-- The EVSE state alone does not close the contactor.
+r = poll((idle:gsub('"vehicle_connected":false', '"vehicle_connected":true')
+  :gsub('"evse_state":1', '"evse_state":11')))
+assert(r.w == 0 and r.charging == false, "state 11 with open contactor")
+
+-- A contactor that says closed while every leg reads 0 V: the grid
+-- voltage must not stand in for the 0 V the charger measured.
+r = poll((idle:gsub('"contactor_closed":false', '"contactor_closed":true')))
+assert(r.w == 0, "closed contactor at 0 V reported " .. tostring(r.w) .. " W")
+
+-- Split-phase installs use grid_v × vehicle_current_a: the same gate holds.
+r = poll(idle, { split_phase = true })
+assert(r.w == 0, "split-phase idle reported " .. tostring(r.w) .. " W")
+
+-- Three-phase charging: the sum of measured V × A on each leg, positive.
+local charging3 = [[{"contactor_closed":true,"vehicle_connected":true,"session_s":1800,
+"grid_v":230.0,"grid_hz":50.0,"vehicle_current_a":16.0,
+"currentA_a":16.1,"currentB_a":16.0,"currentC_a":16.2,"currentN_a":0.3,
+"voltageA_v":230.0,"voltageB_v":229.5,"voltageC_v":230.4,
+"session_energy_wh":4200.0,"config_status":5,"evse_state":11,"current_alerts":[]}]]
+r = poll(charging3)
+-- 230×16.1 + 229.5×16.0 + 230.4×16.2 = 11107.48
+near(r.w, 11107.48, 0.01, "three-phase charging")
+assert(r.connected == true and r.charging == true and r.phases == 3)
+assert(r.session_wh == 4200)
+assert(host._metrics.ev_power_w.value == r.w)
+
+-- One-phase car: unused legs sit at a few volts and do not count.
+r = poll([[{"contactor_closed":true,"vehicle_connected":true,"grid_v":230,
+"vehicle_current_a":16,"currentA_a":16,"currentB_a":0.2,"currentC_a":0.1,
+"voltageA_v":230,"voltageB_v":2.4,"voltageC_v":1.8,"session_energy_wh":100,"evse_state":11}]])
+near(r.w, 3680, 0.01, "one-phase charging")
+assert(r.phases == 1 and r.charging == true)
+
+-- Power measured through a closed contactor counts even if the cable
+-- flag disagrees: a status flag does not cancel measured volts and amps.
+r = poll([[{"contactor_closed":true,"vehicle_connected":false,"grid_v":230,
+"vehicle_current_a":16,"currentA_a":16,"voltageA_v":230,"voltageB_v":0,"voltageC_v":0,
+"session_energy_wh":1,"evse_state":11}]])
+near(r.w, 3680, 0.01, "closed contactor, measured leg")
+
+-- Contactor closed, legs read about 0 V: no power from grid_v.
+r = poll([[{"contactor_closed":true,"vehicle_connected":true,"grid_v":230,
+"vehicle_current_a":10,"voltageA_v":2,"voltageB_v":1,"voltageC_v":0,
+"session_energy_wh":1,"evse_state":11}]])
+assert(r.w == 0, "legs at 0 V reported " .. tostring(r.w) .. " W")
+
+-- A reply with no leg voltage at all: the car sees the measured grid
+-- voltage through the closed contactor.
+r = poll([[{"contactor_closed":true,"vehicle_connected":true,"grid_v":230,
+"vehicle_current_a":10,"session_energy_wh":1,"evse_state":11}]])
+near(r.w, 2300, 0.01, "no leg voltages, grid voltage")
+
+-- Split-phase charging: grid_v × vehicle_current_a.
+r = poll([[{"contactor_closed":true,"vehicle_connected":true,"grid_v":240,
+"vehicle_current_a":32,"currentA_a":40,"currentB_a":40,
+"voltageA_v":120,"voltageB_v":120,"session_energy_wh":50,"evse_state":11}]],
+  { split_phase = true })
+near(r.w, 7680, 0.01, "split-phase charging")
+
+-- A reply without contactor_closed falls back to the EVSE state.
+r = poll([[{"vehicle_connected":true,"evse_state":11,"grid_v":230,"vehicle_current_a":16,
+"currentA_a":16,"voltageA_v":230,"voltageB_v":0,"voltageC_v":0}]])
+near(r.w, 3680, 0.01, "no contactor field, charging state")
+assert(r.charging == true)
+
+print("tesla_wall_connector: all cases pass")

drivers/tests/test_tesla_wall_connector.py

@@ -0,0 +1,12 @@
+"""Tesla Wall Connector reports charge power only through a closed contactor."""
+from pathlib import Path
+import subprocess
+
+
+def test_tesla_wall_connector_charge_power():
+    root = Path(__file__).resolve().parents[2]
+    result = subprocess.run(
+        [str(root / "lua55"), "drivers/tests/lua_harness/test_tesla_wall_connector.lua"],
+        cwd=root, text=True, capture_output=True, check=False,
+    )
+    assert result.returncode == 0, result.stdout + result.stderr

index.yaml

@@ -739,14 +739,14 @@ drivers:
     size_bytes: 10096
     sha256: "d1b8a2cbea20630dcab3cb306df0f6924b0f9ad7f31bcf367fb1d41ca7833350"
   - name: "tesla_wall_connector"
-    version: "0.1.1"
+    version: "0.1.2"
     tier: community
     protocol: http
     connectivity: local
     ders: [ev]
     control: false
-    size_bytes: 8162
-    sha256: "66b6313eda4f68a92a7cc55931baa2408cb6cbb249145f7e6005456fb821d284"
+    size_bytes: 8786
+    sha256: "c365aad2a1216fad870b7dadb32e87feed75627714eeb8160f22cec4db651a80"
   - name: "teslamate_vehicle"
     version: "0.2.0"
     tier: community

manifests/tesla_wall_connector.yaml

@@ -1,5 +1,5 @@
 name: "tesla_wall_connector"
-version: "0.1.1"
+version: "0.1.2"
 tier: community
 author: "Sourceful Labs AB"
 protocol: http
@@ -15,9 +15,9 @@ tested_devices:
     notes: "Tesla Wall Connector Gen 3 on the LAN. Observation only; no local current setpoint."
     min_driver_version: "0.1.0"
 min_host_version: "2.0.0"
-size_bytes: 8162
+size_bytes: 8786
 dkb_id: "tesla_wall_connector"
-sha256: "66b6313eda4f68a92a7cc55931baa2408cb6cbb249145f7e6005456fb821d284"
+sha256: "c365aad2a1216fad870b7dadb32e87feed75627714eeb8160f22cec4db651a80"
 signature: ""
 
 bytecode_sha256: ""

support-status.json

@@ -1682,7 +1682,7 @@
     },
     {
       "catalog_source": true,
-      "catalog_version": "0.1.1",
+      "catalog_version": "0.1.2",
       "driver_id": "tesla_wall_connector",
       "targets": {
         "blixt-l1": {