Properly parse current

load_controller/bms.py

@@ -1,4 +1,6 @@
 from abc import abstractmethod
+import sys
+import struct
 import time
 from dataclasses import dataclass
 from enum import Enum
@@ -9,13 +11,16 @@ from .temperatures import N_SENSORS
 from PySide6.QtCore import QObject, Signal, Slot, Qt
 
 from pymodbus.client import ModbusSerialClient
+from pymodbus.payload import BinaryPayloadDecoder, Endian
 
 MODBUS_BAUDRATE = 115200
 VOLTAGE_ADDRESS = 0x00
+CURRENT_ADDRESS = 2048
 SLAVE_UNIT_ID = 0x02
 
 NUM_CELLS = 3
 VOLTAGE_QUANT = 1 / 10000.0
+CURRENT_QUANT = 1 / (10000 * 500 * 72e-6)
 
 THRESH_UV = 2.5
 THRESH_OV = 4.2
@@ -58,6 +63,8 @@ class BMSData:
     voltages: list[float]
     temperatures: list[float]
     error: BMSError
+    current: float
+    current_integrated: float
 
 
 class BMS(QObject):
@@ -75,7 +82,13 @@ class BMS(QObject):
         self._load = load
         self._num_cells = num_cells
         self._num_sensors = num_sensors
-        self._data = BMSData([0.0] * num_cells, [0.0] * num_sensors, BMSError.NONE)
+        self._data = BMSData(
+            voltages=[0.0] * num_cells,
+            temperatures=[0.0] * num_sensors,
+            error=BMSError.NONE,
+            current=0,
+            current_integrated=0,
+        )
 
     def _check_for_errors(self):
         error = BMSError.NONE
@@ -126,19 +139,29 @@ class BMSEvalBoard(BMS):
 
     def do_work(self):
         while True:
+            self._check_for_errors()
             time.sleep(0.1)
             result = self._dev.read_holding_registers(
                 VOLTAGE_ADDRESS, NUM_CELLS, SLAVE_UNIT_ID
             )
             if result.isError():
-                print(f"ERROR READING VOLTAGES: {result}")
-            else:
-                self._data.voltages = list(
-                    map(lambda v: v * VOLTAGE_QUANT, result.registers)
-                )
-                self._last_voltage_time = time.time()
-                self.dataUpdated.emit(self._data)
-            self._check_for_errors()
+                print(f"ERROR READING VOLTAGES: {result}", file=sys.stderr)
+                continue
+            self._data.voltages = list(
+                map(lambda v: v * VOLTAGE_QUANT, result.registers)
+            )
+            self._last_voltage_time = time.time()
+            result = self._dev.read_holding_registers(CURRENT_ADDRESS, 6, SLAVE_UNIT_ID)
+            if result.isError():
+                print(f"ERROR READING CURRENT: {result}", file=sys.stderr)
+                continue
+            assert len(result.registers) == 6
+            dec = BinaryPayloadDecoder.fromRegisters(result.registers, Endian.Big)
+            self._data.current = dec.decode_32bit_int() * CURRENT_QUANT
+            self._data.current_integrated = (
+                dec.decode_64bit_int() * CURRENT_QUANT * 0.05 / 3600
+            )
+            self.dataUpdated.emit(self._data)
 
     @Slot(list)
     def _updateTemperatures(self, temps: list[float]):

load_controller/gui.py

@@ -89,3 +89,5 @@ class GUI(QObject):
         self._win.setProperty("temp_min", min(data.temperatures))
         self._win.setProperty("temp_max", max(data.temperatures))
         self._win.setProperty("bmsError", str(data.error))
+        self._win.setProperty("currentActual", data.current)
+        self._win.setProperty("currentIntegrated", data.current_integrated)

load_controller/logger.py

@@ -51,6 +51,8 @@ class Logger(QObject):
                     time.time() - self._start_time,
                     self._data.error.value,
                     self._current,
+                    self._data.current,
+                    self._data.current_integrated,
                     *self._data.voltages,
                     *self._data.temperatures,
                 ]

ui/main_window.qml

@@ -13,6 +13,8 @@ ApplicationWindow {
     property string profile: "None"
     property real profileTime: 0
     property real current: 0
+    property real currentActual: 0
+    property real currentIntegrated: 0
     property string time: "00:00 / 00:00"
     property real voltage_min: 0
     property real voltage_max: 0
@@ -143,7 +145,7 @@ ApplicationWindow {
         }
         GridLayout {
             Text {
-                text: "Current [A]:"
+                text: "Current (target) [A]:"
                 Layout.row: 0
                 Layout.column: 0
             }
@@ -153,38 +155,58 @@ ApplicationWindow {
                 Layout.column: 1
             }
             Text {
-                text: "Time [min]:"
+                text: "Current (actual) [A]:"
                 Layout.row: 1
                 Layout.column: 0
             }
+            Text {
+                text: currentActual.toFixed(1)
+                Layout.row: 1
+                Layout.column: 1
+            }
+            Text {
+                text: "Time [min]:"
+                Layout.row: 2
+                Layout.column: 0
+            }
             Text {
                 text: time
-                Layout.row: 1
+                Layout.row: 2
                 Layout.column: 1
             }
             Text {
                 text: "Voltage [V]:"
-                Layout.row: 2
+                Layout.row: 3
                 Layout.column: 0
             }
             Text {
                 text: "[" + voltage_min.toFixed(2) + ", " + voltage_max.toFixed(2) + "]"
-                Layout.row: 2
+                Layout.row: 3
                 Layout.column: 1
             }
             Text {
                 text: "Temperature [°C]:"
-                Layout.row: 3
+                Layout.row: 4
                 Layout.column: 0
             }
             Text {
                 text: "[" + temp_min.toFixed(1) + ", " + temp_max.toFixed(1) + "]"
-                Layout.row: 3
+                Layout.row: 4
+                Layout.column: 1
+            }
+            Text {
+                text: "Coulomb counter [Ah]:"
+                Layout.row: 5
+                Layout.column: 0
+            }
+            Text {
+                text: currentIntegrated.toFixed(1)
+                Layout.row: 5
                 Layout.column: 1
             }
             Text {
                 text: "BMS Error:"
-                Layout.row: 4
+                Layout.row: 6
                 Layout.column: 0
                 visible: bmsErrorVisible
                 color: "red"
@@ -192,7 +214,7 @@ ApplicationWindow {
             }
             Text {
                 text: bmsError
-                Layout.row: 4
+                Layout.row: 6
                 Layout.column: 1
                 visible: bmsErrorVisible
                 color: "red"