CY8CKIT042-BLE ADC的最大电压是多少？

你好柏柏社区！
我最近开始在CY8CKIT-042-BLE（CY8C4247LQI-BLE，具体地）为办公室的一个小型研发项目进行实验。在没有太多细节的情况下，我们试图精确测量可变电阻的电阻。特别是，我在这个应用中测量9个单独的电阻器的电阻。
我已经附上了我设法凑在一起的项目文件，这看起来现在起作用了（请原谅写得不好的代码和糟糕的配置图，这里仍然是新的）。我已经声明了适当的模拟引脚，传感器的一端连接到，而所有传感器的接地端都连接到J1上的GND。CopsCH将传感器连接到AMUX，AMUX使用IDAC和ADC块的组合来向每一个模拟引脚注入少量电流，然后ADC测量每个电阻器两端的电压降。从这个，我可以采取已知的电流和测量电压和（V＝IR）计算在那个时间点的传感器的电阻。
对于设计文件还有一点，但大部分是1）准确地收集所收集的数据，并且2）创建一个UART连接，这样我就可以在终端上打印这些值并将它们捕获到我的PC上的文本文件。
好的，几个重要的问题：
1）ADC的最大电压是多少？ADC块具有Vref连接到VDDA，并且单端负输入也被设置为Vref。这将“单端模式范围”设置为“VDDA（3.3 V）至0”，并且，当我完全从板断开传感器时，我看到3.301643伏印刷到终端（打开连接）。我知道这些非常接近，但它们并不完全相同。这种差异是正常的吗？
2）我的ADC被配置为12位，它应该是4096计数全范围。当我增加了我的传感器的电阻，我可以得到它高达8200个计数，这只是超过13位。我的ADC配置不正确吗？
3）我注意到，对于单个传感器来说，ADC报告的一些电压在返回到其他传感器的标称水平之前，会被“1000”计数“翘起”。我已经伸出了传感器供应商，并且在确认我已经连接了电池到工具箱以稳定电路板电压（它只是在USB电缆之前供电）。他们已经评论说，ADC的固有电容相对于AD的时序可能会发生一些事情。C读数。有没有人知道我如何量化和改变我适应的时间？
对于长时间的道歉，非常感谢您的任何评论！如果这是张贴在错误的部分，请指出我在正确的方向。
谢谢您！
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     以下为原文
  Hello Cypress community!

I recently started experimenting with the CY8CKIT-042-BLE (CY8C4247LQI-BLE, to be specific) for a small R&D project in the office. Without going into too much detail, we're trying to accurately measure the resistance of a variable resistor. In particular, I'm measuring the resistance of 9 separate resistors in this application.

I've attached the Project file I've managed to cobble together that seems to work at the moment (please excuse poorly written code and badly configured diagrams, still new here). I've declared the proper analog pins that one end of the sensors are connected to, while the grounded end of all the sensors are connected together to GND on J1. The TopDesign.cysch connects the sensors to an AMux, which uses a combination of the IDAC and ADC blocks to inject a small amount of current to each of the analog pins, and then ADC measures the voltage drop across each resistor. From this, I can take the known current and measured voltage and (V = IR) calculate the resistance of the sensor at that point in time.

There's a little more to the design file, but most of it is to 1) accurately timestamp the collected data, and 2) create a UART connection such that I can print the values over terminal and capture them to a text file on my PC.

Okay, a couple important questions:

1) What is the maximum voltage I should expect into the ADC? The ADC block had Vref connected to VDDA, and the single-ended negative input is also set to Vref. This sets the "Single ended mode range" to "Vdda (3.3 V) to 0.0", and, when I disconnect the sensor entirely from the board, I see 3.301643 volts printed to the terminal (open connection). I know these are quite close, but they're not quite the same. Is this discrepancy normal?

2) I've got the ADC configured to be 12-bit, which should be 4096 counts full range. When I increase the resistance of my sensor, I can get it as high as ~8200 counts, which just exceeds 13 bits. Do I have my ADC configured incorrectly?

3) I've noticed that occasionally some of the voltages reported by the ADC for an individual sensor will "blip" up by a few 1000 counts before coming back down to the nominal level of the other sensors. I've reached out the sensor vendor, and after confirming that I've connected a battery to the kit to stabilize the board voltage (it was just powered off the USB cable before) they've commented that something could be going on with the inherent capacitance of the ADC relative to the timing of my ADC readings. Does anyone have any insight into how I can quantify this and change my timing to accomodate?

Apologies for the long read, any comments are greatly appreciated! If this is posted to the wrong section please point me in the right direction.

Thank you!

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