python - 使用 phidget 在 2 个计量单元之间添加

Question

我正在使用 Phidg​​et Bridge 4 输入来获取 2 个计量单元的信号。然后我想在信号之间进行加法和乘法但无法管理onVoltageRatioChange功能。

首先，我尝试从函数返回信号onVoltageRatioChange以便在内部使用它main但没有成功..

然后，在函数内部，我尝试根据通道设置一个具有接收值的变量，然后在信号之间进行计算，但在这里我也遇到了一个错误：

错误：t = channel0 + channel1 UnboundLocalError：分配前引用了局部变量“channel0”

    TIME_OUT = 5000 #5s beofre it throws a timeout exception 
    DATA_INTERVAL = 20 #1000ms sample frequency 
    A0 = 1
    B0 = 0
    offset = 0 # 10.45
    channel0 = 0
    channel1 = 0
    
    def onVoltageRatioChange(self, voltageRatio):
        Masse = (voltageRatio - (B0) ) / (A0) + offset
    
        if(self.getChannel() == 0):
            channel0 = voltageRatio
    
        if(self.getChannel() == 1):
            channel1 = voltageRatio
    
        t = channel0 + channel1
        print(t)
    
    def main():
    
        voltageRatioInput0 = VoltageRatioInput()
        voltageRatioInput1 = VoltageRatioInput()
        voltageRatioInput2 = VoltageRatioInput()
        voltageRatioInput3 = VoltageRatioInput()
    
        voltageRatioInput0.setChannel(0)
        voltageRatioInput1.setChannel(1)
        voltageRatioInput2.setChannel(2)
        voltageRatioInput3.setChannel(3)
    
        voltageRatioInput0.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
        voltageRatioInput1.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
        voltageRatioInput2.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
        voltageRatioInput3.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
    
        voltageRatioInput0.openWaitForAttachment(TIME_OUT)
        voltageRatioInput1.openWaitForAttachment(TIME_OUT)
        voltageRatioInput2.openWaitForAttachment(TIME_OUT)
        voltageRatioInput3.openWaitForAttachment(TIME_OUT)
    
        voltageRatioInput0.setDataInterval(DATA_INTERVAL)
        voltageRatioInput1.setDataInterval(DATA_INTERVAL)
        voltageRatioInput2.setDataInterval(DATA_INTERVAL)
        voltageRatioInput3.setDataInterval(DATA_INTERVAL)
    
    
        while True:
            time.sleep(10)
            
            voltageRatioInput0.close()
            voltageRatioInput1.close()
            voltageRatioInput2.close()
            voltageRatioInput3.close()
    
    main()

标签： pythonphidgets