hitl_tester.test_cases.bms.test_impedance

Measure impedance by triggering a pulse (0-1A) for 0.25 seconds and measuring the voltage. Impedance = delta V / delta I

Run with python3 hitl_tester.py devel_test.plan -c

Used in these test plans:

devel_test ⠀⠀⠀(bms/devel_test.plan)
devel_test ⠀⠀⠀(bms/devel_test.plan)

Example Command (warning: test plan may run other test cases):

./hitl_tester.py devel_test

View Source

 1"""
 2Measure impedance by triggering a pulse (0-1A) for 0.25 seconds and measuring the voltage.
 3Impedance = delta V / delta I
 4
 5Run with `python3 hitl_tester.py devel_test.plan -c`
 6"""
 7
 8import math
 9
10import pytest
11
12from hitl_tester.modules.bms.bms_hw import BMSHardware
13
14bms_hardware = BMSHardware(pytest.flags)  # type: ignore[arg-type]
15bms_hardware.init()
16
17
18def calculate_impedance(data: list[float]) -> float:
19    """Calculate the impedance from the raw voltages."""
20    for i, voltage in enumerate(data):
21        if i > 0 and data[i - 1] - voltage > 0.001:
22            for j in range(8):
23                print(data[i - 2 + j])
24            return (data[i - 1] - data[i + 2]) * 1000
25    return math.nan
26
27
28def test_impedance():
29    """Record the voltage drop with a current pulse."""
30    bms_hardware.load.configure_pulse_trigger()
31    bms_hardware.dmm.configure_voltage_trigger()
32    bms_hardware.load.enable()
33    bms_hardware.dmm.send_trigger()  # Begin voltage measurements
34    bms_hardware.load.send_trigger()  # Pulse the current
35    bms_hardware.load.wait_for_pulse()  # Wait for load pulse to complete
36    bms_hardware.load.disable()
37    data = bms_hardware.dmm.read_internal_memory()
38    bms_hardware.dmm.configure_voltage_normal()
39    print(data)
40    print(f"Impedance: {calculate_impedance(data)}")

bms_hardware = <hitl_tester.modules.bms.bms_hw.BMSHardware object>

def calculate_impedance(data: list[float]) -> float: View Source

19def calculate_impedance(data: list[float]) -> float:
20    """Calculate the impedance from the raw voltages."""
21    for i, voltage in enumerate(data):
22        if i > 0 and data[i - 1] - voltage > 0.001:
23            for j in range(8):
24                print(data[i - 2 + j])
25            return (data[i - 1] - data[i + 2]) * 1000
26    return math.nan

Calculate the impedance from the raw voltages.

def test_impedance(): View Source

29def test_impedance():
30    """Record the voltage drop with a current pulse."""
31    bms_hardware.load.configure_pulse_trigger()
32    bms_hardware.dmm.configure_voltage_trigger()
33    bms_hardware.load.enable()
34    bms_hardware.dmm.send_trigger()  # Begin voltage measurements
35    bms_hardware.load.send_trigger()  # Pulse the current
36    bms_hardware.load.wait_for_pulse()  # Wait for load pulse to complete
37    bms_hardware.load.disable()
38    data = bms_hardware.dmm.read_internal_memory()
39    bms_hardware.dmm.configure_voltage_normal()
40    print(data)
41    print(f"Impedance: {calculate_impedance(data)}")

Record the voltage drop with a current pulse.