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heartratemonitors [2023/07/24 10:54] wangzihao |
heartratemonitors [2023/07/26 17:55] (当前版本) wangzihao [5. 参考案例] |
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[AD8232 ECG模块引脚排列,与Arduino接口,应用 (microcontrollerslab.com)](https://microcontrollerslab.com/ad8232-ecg-module-pinout-interfacing-with-arduino-applications-features/) | [AD8232 ECG模块引脚排列,与Arduino接口,应用 (microcontrollerslab.com)](https://microcontrollerslab.com/ad8232-ecg-module-pinout-interfacing-with-arduino-applications-features/) | ||
+ | **下面是个人案例,使用Mircopython编写程序驱动RP2040读取Max30102的数据。** | ||
+ | |||
+ | ####电路连接 | ||
+ | |||
+ | {{ :rp2040-max30102.png?900 |}} | ||
+ | |||
+ | ####程序代码 | ||
+ | |||
+ | 驱动文件包含三个.py文件。 | ||
+ | |||
+ | - _init_.py | ||
+ | - circular_buffer.py | ||
+ | - 检测心率.py | ||
+ | |||
+ | 前面两个文件可在后面链接中下载:https://github.com/n-elia/MAX30102-MicroPython-driver/tree/main/max30102 | ||
+ | |||
+ | 检测心率.py程序如下 | ||
+ | |||
+ | from machine import SoftI2C, Pin, Timer | ||
+ | from utime import ticks_diff, ticks_us | ||
+ | from max30102 import MAX30102, MAX30105_PULSE_AMP_MEDIUM | ||
+ | |||
+ | BEATS = 0 # 存储心率 | ||
+ | FINGER_FLAG = False # 默认表示未检测到手指 | ||
+ | |||
+ | |||
+ | def display_info(t): | ||
+ | # 如果没有检测到手指,那么就不显示 | ||
+ | if FINGER_FLAG is False: | ||
+ | return | ||
+ | |||
+ | print('心率: ', BEATS) | ||
+ | |||
+ | |||
+ | def main(): | ||
+ | global BEATS, FINGER_FLAG # 如果需要对全局变量修改,则需要global声明 | ||
+ | | ||
+ | # 创建I2C对象(检测MAX30102) | ||
+ | i2c = SoftI2C(sda=Pin(16), scl=Pin(17), freq=400000) # Fast: 400kHz, slow: 100kHz | ||
+ | |||
+ | # 创建传感器对象 | ||
+ | sensor = MAX30102(i2c=i2c) | ||
+ | |||
+ | # 检测是否有传感器 | ||
+ | if sensor.i2c_address not in i2c.scan(): | ||
+ | print("没有找到传感器") | ||
+ | return | ||
+ | elif not (sensor.check_part_id()): | ||
+ | # 检查传感器是否兼容 | ||
+ | print("检测到的I2C设备不是MAX30102或者MAX30105") | ||
+ | return | ||
+ | else: | ||
+ | print("传感器已识别到") | ||
+ | |||
+ | print("使用默认配置设置传感器") | ||
+ | sensor.setup_sensor() | ||
+ | |||
+ | # 对传感器进行设定 | ||
+ | sensor.set_sample_rate(400) | ||
+ | sensor.set_fifo_average(8) | ||
+ | sensor.set_active_leds_amplitude(MAX30105_PULSE_AMP_MEDIUM) | ||
+ | |||
+ | t_start = ticks_us() # Starting time of the acquisition | ||
+ | |||
+ | MAX_HISTORY = 32 | ||
+ | history = [] | ||
+ | beats_history = [] | ||
+ | beat = False | ||
+ | |||
+ | while True: | ||
+ | sensor.check() | ||
+ | if sensor.available(): | ||
+ | # FIFO 先进先出,从队列中取数据。都是整形int | ||
+ | red_reading = sensor.pop_red_from_storage() | ||
+ | ir_reading = sensor.pop_ir_from_storage() | ||
+ | | ||
+ | if red_reading < 1000: | ||
+ | print('No finger') | ||
+ | FINGER_FLAG = False # 表示没有放手指 | ||
+ | continue | ||
+ | else: | ||
+ | FINGER_FLAG = True # 表示手指已放 | ||
+ | |||
+ | # 计算心率 | ||
+ | history.append(red_reading) | ||
+ | | ||
+ | # 为了防止列表过大,这里取列表的后32个元素 | ||
+ | history = history[-MAX_HISTORY:] | ||
+ | | ||
+ | # 提取必要数据 | ||
+ | minima, maxima = min(history), max(history) | ||
+ | threshold_on = (minima + maxima * 3) // 4 # 3/4 | ||
+ | threshold_off = (minima + maxima) // 2 # 1/2 | ||
+ | | ||
+ | if not beat and red_reading > threshold_on: | ||
+ | beat = True | ||
+ | t_us = ticks_diff(ticks_us(), t_start) | ||
+ | t_s = t_us/1000000 | ||
+ | f = 1/t_s | ||
+ | bpm = f * 60 | ||
+ | if bpm < 500: | ||
+ | t_start = ticks_us() | ||
+ | beats_history.append(bpm) | ||
+ | beats_history = beats_history[-MAX_HISTORY:] # 只保留最大30个元素数据 | ||
+ | BEATS = round(sum(beats_history)/len(beats_history), 2) # 四舍五入 | ||
+ | if beat and red_reading < threshold_off: | ||
+ | beat = False | ||
+ | |||
+ | |||
+ | if __name__ == '__main__': | ||
+ | |||
+ | tim = Timer(period=1000, mode=Timer.PERIODIC, callback=display_info) | ||
+ | | ||
+ | main() | ||
+ | |||
+ | ####运行效果 | ||
+ | |||
+ | {{ :hrm_test.png?400 |}} | ||