ADuCM350 Evaluation Board UART Handshaking Error 

I have a problem with “ADuCM350 Evaluation Board UART Handshaking Error ”
-    I try to measure 100KOhm resistor by using 2-wire configuration with “Switch Mux Config Board”
-    I remove K10, K11, K12 for just connect the AFE3 & AFE4 to 100K.
-    If I let AFE3 & AFE4 open when hit “Go” button then the GUI response and give the “Inf” value in the “Measured Unknown Impedance Magnitude” box.
-    If I connect 100k to AFE3 & AFE4 then GUI comebacks with “UART Handshaking Error” window.

Please helps, thanks

  • +1
    •  Analog Employees 
    on Jan 9, 2018 11:28 AM

    Hi,

    I tried your settings and I encountered several handshaking errors as well. What I noticed is that this error is more frequent with the excitation voltage = 3mV when measuring resistance around 100kOhm. Raising the excitation voltage reduces or even remove this error, and I can't explain the reason of that. 

    What I would say here is that when 3mV is used to measure 100kOhm resistance, the ADC is only seeing 270uV from the TIA. This is actually low and will result in an inaccurate data. What you can do is to either increase the excitation voltage or increase the TIA gain. I will also advise adjusting RCAL somewhere near or equal to the lowest expected sensor impedance. 

    -Mark

  • Hi Mark,

    Thanks for spend times of recreate the problem and find the root cause.

    I am very appreciate your helps and information.

    Have a good day!

    T. Nguyen

  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:00 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin