miniSMU MS01 可透過官方 Python 函式庫 minismu_py 以程式控制。此介面讓您能方便地實現量測自動化、執行複雜的測試序列,並將 miniSMU 整合到您自訂的應用程式與研究工作流程中。
安裝
使用 pip 直接從 PyPI 安裝 minismu_py 函式庫:
pip install minismu_py
此函式庫的相依套件極少,需要:
- Python 3.6 或更新版本
- pyserial 套件(用於 USB 連線)
- tqdm 套件(選用,範例中用於顯示進度列)
開始使用
基本連線
開始使用 Python 介面前,您需要先與 miniSMU MS01 建立連線:
from minismu_py import SMU, ConnectionType
# For USB connection
smu = SMU(ConnectionType.USB, port="/dev/ttyACM0") # Linux/Mac
# or
smu = SMU(ConnectionType.USB, port="COM3") # Windows
# For WiFi connection
smu = SMU(ConnectionType.NETWORK, host="192.168.1.100", tcp_port=3333)
# Verify connection
print("Device Info:", smu.get_identity())
使用 context manager
SMU 類別支援 Python 的 context manager(情境管理器)協定,可自動處理資源的清理:
from minismu_py import SMU, ConnectionType
# Using context manager ensures proper cleanup
with SMU(ConnectionType.USB, port="COM3") as smu:
# Work with the SMU
print("Device Info:", smu.get_identity())
# No need to explicitly close the connection
# It will be closed automatically when exiting the 'with' block
基本量測範例
以下是一個簡單的範例,示範如何設定通道、設定電壓並進行量測:
from minismu_py import SMU, ConnectionType
import time
with SMU(ConnectionType.USB, port="COM3") as smu:
# Configure channel 1
smu.set_mode(1, "FVMI") # Force Voltage, Measure Current mode
smu.set_voltage_range(1, "AUTO")
smu.enable_channel(1)
# Set voltage to 3.3V
smu.set_voltage(1, 3.3)
time.sleep(0.1) # Allow settling time
# Take measurements
voltage, current = smu.measure_voltage_and_current(1)
print(f"Voltage: {voltage:.6f}V")
print(f"Current: {current:.6f}A")
# Disable the channel when done
smu.disable_channel(1)
重要概念
連線類型
此函式庫支援兩種連線方式:
USB 連線:透過 USB 線直接連接
smu = SMU(ConnectionType.USB, port="COM3")網路連線:透過 Wi-Fi 連線
smu = SMU(ConnectionType.NETWORK, host="192.168.1.100")
量測模式
miniSMU 支援兩種主要的量測模式:
FVMI(施加電壓、量測電流)
- 施加指定的電壓,並量測產生的電流
- 適用於電阻特性量測、二極體測試等
smu.set_mode(1, "FVMI")FIMV(施加電流、量測電壓)
- 施加指定的電流,並量測產生的電壓
- 適用於 LED 測試、電池特性量測等
smu.set_mode(1, "FIMV")
錯誤處理
此函式庫透過 SMUException 類別提供自訂的例外處理:
from minismu_py import SMU, ConnectionType, SMUException
try:
with SMU(ConnectionType.USB, port="COM3") as smu:
# SMU operations
pass
except SMUException as e:
print(f"SMU Error: {e}")
except Exception as e:
print(f"Unexpected error: {e}")
常用操作
裝置資訊
# Get device identity
identity = smu.get_identity()
print(f"Connected to: {identity}")
# Get system temperatures
adc_temp, ch1_temp, ch2_temp = smu.get_temperatures()
print(f"Temperatures: ADC: {adc_temp}°C, CH1: {ch1_temp}°C, CH2: {ch2_temp}°C")
通道設定
# Select channel to configure
channel = 1
# Set mode (FVMI: Force Voltage, Measure Current)
smu.set_mode(channel, "FVMI")
# Set voltage range (AUTO, LOW, HIGH)
smu.set_voltage_range(channel, "AUTO")
# Enable channel
smu.enable_channel(channel)
設定輸出值
# Set voltage (in volts)
smu.set_voltage(1, 3.3)
# Set current (in amperes)
smu.set_current(2, 0.01) # 10mA
進行量測
# Measure voltage only
voltage = smu.measure_voltage(1)
print(f"Voltage: {voltage}V")
# Measure current only
current = smu.measure_current(1)
print(f"Current: {current}A")
# Measure both voltage and current in one command
voltage, current = smu.measure_voltage_and_current(1)
print(f"Voltage: {voltage}V, Current: {current}A")
控制通道狀態
# Enable channel
smu.enable_channel(1)
# Disable channel
smu.disable_channel(1)
進階功能
電壓掃描
您可以執行電壓掃描來產生 I-V 曲線:
import csv
from tqdm import tqdm
import time
def voltage_sweep(smu, channel=1, start=-1.0, stop=1.0, step=0.1):
"""Perform a voltage sweep and measure current"""
try:
# Configure channel
smu.set_mode(channel, "FVMI")
smu.set_voltage_range(channel, "AUTO")
smu.enable_channel(channel)
# Create voltage points
voltages = [round(v, 3) for v in
[start + step*i for i in range(int((stop-start)/step) + 1)]]
results = []
# Create progress bar
for voltage in tqdm(voltages, desc="Voltage Sweep"):
smu.set_voltage(channel, voltage)
time.sleep(0.1) # Allow settling time
v, i = smu.measure_voltage_and_current(channel)
results.append({
'target_voltage': voltage,
'measured_voltage': v,
'measured_current': i
})
return results
finally:
# Always disable channel after measurement
smu.disable_channel(channel)
# Run voltage sweep and save results
with SMU(ConnectionType.USB, port="COM3") as smu:
sweep_results = voltage_sweep(smu, channel=1, start=-1.0, stop=1.0, step=0.05)
# Save results to CSV
with open('voltage_sweep_results.csv', 'w', newline='') as f:
writer = csv.DictWriter(f, fieldnames=[
'target_voltage', 'measured_voltage', 'measured_current'])
writer.writeheader()
writer.writerows(sweep_results)
print("Results saved to voltage_sweep_results.csv")
資料串流
進行高速資料擷取時,miniSMU 支援資料串流:
import time
import csv
from tqdm import tqdm
from datetime import datetime
def stream_data(smu, channel=1, duration=10.0, sample_rate=100.0, voltage=3.3):
"""Stream data from the SMU for a specified duration"""
try:
# Configure channel
smu.set_mode(channel, "FVMI")
smu.enable_channel(channel)
smu.set_voltage(channel, voltage)
# Configure streaming
smu.set_sample_rate(channel, sample_rate)
# Set miniSMU's internal time for timestamping
current_time = int(time.time() * 1000) # Convert to milliseconds
smu.set_time(current_time)
# Calculate number of samples
num_samples = int(duration * sample_rate)
# Prepare data storage
timestamps = []
voltages = []
currents = []
# Start streaming
print("Starting streaming...")
smu.start_streaming(channel)
# Collect data with progress bar
pbar = tqdm(total=num_samples, desc="Streaming Data")
while len(timestamps) < num_samples:
try:
# Read streaming data packet
data_channel, t, v, i = smu.read_streaming_data()
# Only process data from the requested channel
if data_channel == channel:
timestamps.append(t)
voltages.append(v)
currents.append(i)
pbar.update(1)
except Exception as e:
print(f"\nError reading streaming data: {e}")
break
# Stop streaming
smu.stop_streaming(channel)
pbar.close()
# Save data to CSV
filename = f'streaming_data_{datetime.now().strftime("%Y%m%d_%H%M%S")}.csv'
with open(filename, 'w', newline='') as f:
writer = csv.writer(f)
writer.writerow(['Timestamp (s)', 'Voltage (V)', 'Current (A)'])
for t, v, i in zip(timestamps, voltages, currents):
writer.writerow([t, v, i])
print(f"Data saved to {filename}")
return timestamps, voltages, currents
finally:
# Always cleanup
smu.disable_channel(channel)
smu.stop_streaming(channel)
# Stream data for 5 seconds at 100Hz
with SMU(ConnectionType.USB, port="COM3") as smu:
timestamps, voltages, currents = stream_data(
smu,
channel=1,
duration=5.0,
sample_rate=100.0,
voltage=3.3
)
四線式克耳文量測
進行可消除導線電阻影響的高準確度量測:
with SMU(ConnectionType.USB, port="COM3") as smu:
# Enable 4-wire mode (CH2 becomes sense channel)
smu.enable_fourwire_mode()
# Configure CH1 as voltage source
smu.set_mode(1, "FVMI")
smu.set_voltage(1, 1.0)
smu.enable_channel(1)
# Measure - returns CH1 current and CH2 (sense) voltage
voltage, current = smu.measure_voltage_and_current(1)
resistance = voltage / current
print(f"True resistance: {resistance:.6f} Ohm")
# Disable 4-wire mode when done
smu.disable_fourwire_mode()
Wi-Fi 設定
此函式庫提供管理 Wi-Fi 設定的函式:
# Scan for available networks
networks = smu.wifi_scan()
for network in networks:
print(f"SSID: {network['ssid']}, RSSI: {network['rssi']}")
# Configure WiFi credentials
smu.set_wifi_credentials("YourNetworkSSID", "YourPassword")
# Enable WiFi
smu.enable_wifi()
# Check WiFi status
status = smu.get_wifi_status()
print(f"Connected: {status.connected}")
print(f"SSID: {status.ssid}")
print(f"IP Address: {status.ip_address}")
print(f"Signal Strength: {status.rssi}dBm")
應用範例
元件特性量測
此範例執行電壓掃描並分析結果,以量測二極體的特性:
import numpy as np
import matplotlib.pyplot as plt
from minismu_py import SMU, ConnectionType
with SMU(ConnectionType.USB, port="COM3") as smu:
# Configure channel
smu.set_mode(1, "FVMI")
smu.enable_channel(1)
# Perform voltage sweep
voltages = np.linspace(-0.5, 1.0, 100) # -0.5V to 1.0V in 100 steps
measured_voltages = []
measured_currents = []
for v in voltages:
smu.set_voltage(1, v)
time.sleep(0.05) # Allow settling time
mv, mi = smu.measure_voltage_and_current(1)
measured_voltages.append(mv)
measured_currents.append(mi)
# Disable channel when done
smu.disable_channel(1)
# Plot results
plt.figure(figsize=(10, 6))
plt.plot(measured_voltages, measured_currents * 1000) # Convert to mA
plt.grid(True)
plt.xlabel('Voltage (V)')
plt.ylabel('Current (mA)')
plt.title('Diode I-V Characteristic')
plt.savefig('diode_iv_curve.png')
plt.show()
自動化測試序列
此範例示範電池的自動化測試序列:
import time
import csv
from datetime import datetime
from minismu_py import SMU, ConnectionType
def battery_discharge_test(smu, channel=1, discharge_current=0.01, cutoff_voltage=3.0):
"""Perform battery discharge test until cutoff voltage is reached"""
try:
# Configure for constant current discharge (FIMV mode)
smu.set_mode(channel, "FIMV")
smu.enable_channel(channel)
# Set discharge current (negative for discharge)
smu.set_current(channel, -discharge_current)
# Prepare data storage
start_time = time.time()
results = []
print(f"Starting battery discharge test at {discharge_current*1000:.1f}mA")
print(f"Test will run until battery voltage reaches {cutoff_voltage}V")
# Run test until cutoff voltage is reached
while True:
# Measure voltage and current
voltage, current = smu.measure_voltage_and_current(channel)
# Calculate elapsed time
elapsed_time = time.time() - start_time
# Record data
results.append({
'time': elapsed_time,
'voltage': voltage,
'current': current
})
# Display progress
print(f"\rTime: {elapsed_time:.1f}s, Voltage: {voltage:.3f}V, Current: {current*1000:.1f}mA", end="")
# Check if cutoff voltage reached
if voltage <= cutoff_voltage:
print("\nCutoff voltage reached. Test complete.")
break
# Wait before next measurement
time.sleep(5) # Take measurements every 5 seconds
# Save results
filename = f'battery_discharge_{datetime.now().strftime("%Y%m%d_%H%M%S")}.csv'
with open(filename, 'w', newline='') as f:
writer = csv.DictWriter(f, fieldnames=['time', 'voltage', 'current'])
writer.writeheader()
writer.writerows(results)
print(f"Results saved to {filename}")
return results
finally:
# Always disable channel when done
smu.disable_channel(channel)
# Run battery discharge test
with SMU(ConnectionType.USB, port="COM3") as smu:
battery_discharge_test(
smu,
channel=1,
discharge_current=0.01, # 10mA discharge
cutoff_voltage=3.0 # 3.0V cutoff
)
API 參考
連線管理
| 方法 | 說明 |
|---|---|
SMU(connection_type, port, host, tcp_port) | 初始化 SMU 連線 |
close() | 關閉連線 |
get_identity() | 取得裝置識別資訊 |
reset() | 重設裝置 |
輸出與量測
| 方法 | 說明 |
|---|---|
set_voltage(channel, voltage) | 設定指定通道的電壓 |
set_current(channel, current) | 設定指定通道的電流 |
measure_voltage(channel) | 量測指定通道的電壓 |
measure_current(channel) | 量測指定通道的電流 |
measure_voltage_and_current(channel) | 同時量測電壓與電流 |
通道設定
| 方法 | 說明 |
|---|---|
enable_channel(channel) | 啟用指定通道 |
disable_channel(channel) | 停用指定通道 |
set_voltage_range(channel, range_type) | 設定電壓檔位(AUTO/LOW/HIGH) |
set_mode(channel, mode) | 設定通道模式(FIMV/FVMI) |
資料串流
| 方法 | 說明 |
|---|---|
start_streaming(channel) | 開始資料串流 |
stop_streaming(channel) | 停止資料串流 |
read_streaming_data() | 讀取串流資料封包(通道、時間戳記、電壓、電流) |
set_sample_rate(channel, rate) | 設定取樣率,單位為 Hz |
系統設定
| 方法 | 說明 |
|---|---|
set_led_brightness(brightness) | 設定 LED 亮度(0-100) |
get_led_brightness() | 取得目前的 LED 亮度 |
get_temperatures() | 取得系統溫度(ADC、通道 1、通道 2) |
set_time(timestamp) | 設定裝置的內部時鐘(Unix 時間戳記,單位為毫秒) |
enable_fourwire_mode() | 啟用四線式克耳文量測模式 |
disable_fourwire_mode() | 停用四線式模式,恢復為獨立通道 |
get_fourwire_mode() | 查詢四線式模式的狀態(傳回 bool) |
Wi-Fi 設定
| 方法 | 說明 |
|---|---|
wifi_scan() | 掃描可用的 Wi-Fi 網路 |
get_wifi_status() | 取得目前的 Wi-Fi 狀態 |
set_wifi_credentials(ssid, password) | 設定 Wi-Fi 認證資訊 |
enable_wifi() | 啟用 Wi-Fi |
disable_wifi() | 停用 Wi-Fi |
最佳做法
以下是使用 minismu_py 函式庫時的建議做法:
1. 使用 context manager
務必使用 Python 的 context manager,以確保正確清理資源:
with SMU(ConnectionType.USB, port="COM3") as smu:
# Code here
2. 務必停用通道
量測完成後,請停用通道:
try:
smu.enable_channel(1)
# Your measurement code
finally:
smu.disable_channel(1)
3. 加入穩定時間
加入穩定時間,以獲得穩定的量測結果:
smu.set_voltage(1, 3.3)
time.sleep(0.1) # Allow settling time before measuring
4. 妥善處理例外
實作適當的例外處理:
try:
# SMU operations
except SMUException as e:
print(f"SMU Error: {e}")
5. 檢查連線狀態
執行操作前,請先確認連線:
identity = smu.get_identity()
if not identity:
print("Device not responding")
6. 關閉連線
完成後,務必關閉連線:
smu.close()
疑難排解
常見問題
無法連接裝置
- 確認裝置已開機
- 檢查 USB 線的連接
- 確認連接埠名稱正確
- 確保沒有其他軟體正在使用該連接埠
通訊錯誤
- 重設裝置
- 關閉後重新開啟連線
- 檢查是否有干擾或纜線問題
- 確認鮑率正確(115200)
量測結果不如預期
- 檢查通道設定(模式、檔位)
- 預留足夠的穩定時間
- 確認與待測元件的連接
- 檢查保護限值
Wi-Fi 連線問題
- 確保 Wi-Fi 天線已正確安裝
- 確認 Wi-Fi 認證資訊
- 檢查訊號強度
- 先透過 USB 連線來設定 Wi-Fi
更多資源
如需更多進階範例與詳細說明文件,請造訪上方的官方儲存庫與說明文件連結。