Delta Sigma作为PID循环的一部分给出了奇怪的读数

我远离计算机，不能检查原理图，但我怀疑FET电路有噪声拾取，特别是如果PWM控制的话。我建议添加小帽子来滤除噪音。检查输入信号的范围。
奥迪赛1



     以下为原文
   I am away from computer and can't inspect the schematic, but I suspect there is noise pickup from the FET circuit, particularly if it PWM-controlled. I would recommend adding small cap to filter out noise. Check incoming signal with scope.
odissey1
 
 

不坏的想法，但我不认为这是一个噪音问题。我用电池作为FET电路的电源，尽量减少电路中的噪声，但没有效果。
在电流感应电阻和输入电源之间增加100NF根本没有帮助这种情况。
什么* *帮助重新分配ADC引脚从哪里到另一个引脚。我不明白为什么这是可能的，但是一旦我把ADC从PIN 0.4变为0.2，问题似乎已经解决了。我想知道这是否与我使用运算放大器2的事实有关，P0.4与OA2的非反相输入有关。理论上，运算放大器应该内部断开，但实际上，也许不是。或者，在非反相输入端的信号中可能会有一些噪声流过？我不知道。



     以下为原文
  Not a bad thought, but I don't think this is a noise issue. I've used a battery as the power supply to the FET circuit to try and minimize the noise in that circuit but to no avail.
 
Adding 100nF across the current sense resistor and across the input supply did nothing at all to help the situation.
 
What *did* help was reassigning the ADC pin from where it was to another pin. I'll not get into why that was possible, but as soon as I changed the ADC from being on pin 0.4 to 0.2 the problem seems to have resolved. I'm wondering if that is somehow related to the fact that I'm using op-amp 2, and P0.4 is tied to the non-inverting input of OA2? Theoretically, the op-amp should be internally disconnected but practically, perhaps it wasn't? Or perhaps some noise bleeds across from the signal on the non-inverting input? I don't know.