Hello Keith, thanks for your quick response! Checking the HW signals again (with a multimeter), I found the following: DC1 (IC8): Pin30 (DVDD): 3.294V Pin32 (AVDD): 5.013V Pin2 (DECAP): 3.092V Pin5 (REFP): 0.000V Pin6 (REFP): 0.000V Pin 20 (ADC-INM): 0V Pin 17 (ADC-INP): 3.372V Pin 9 (AIN0): 3.371V Pin 10 (AIN1): 0.160V Powering Discovery board (so, the MUX should now switch to AIN1) => Pin 17 (ADC-INP) has same signal as Pin 9 (AIN0), not Pin 10 (AIN1) ADC2 (IC9): Pin30 (DVDD): 3.294V Pin32 (AVDD): 5.012V Pin2 (DECAP): 3.080V Pin5 (REFP): 0.000V Pin6 (REFP): 0.000V Pin 20 (ADC-INM): 0V Pin 17 (ADC-INP): 3.373V Pin 9 (AIN0): 3.371V Pin 10 (AIN1): 0.294V Powering Discovery board (so, the MUX should now switch to AIN1) => Pin 17 (ADC-INP) has same signal as Pin 9 (AIN0), not Pin 10 (AIN1) So, according to your hint, I guess there's some problem with the internal reference. So I check up on this. Meanwhile I have also tried adding another 24 SCLKs and /CS signal, but to no avail: By the way, I've also reduced the baudrate (but that didn't help either). Also, the Discovery board uses a 3V reference, while we're using 3.3V supply voltage for the ADS8168 . But as far as I've been able to find out, this should be no problem with the logical levels. For the timings, I've also produced some zoomed in scope images: Obviously, the ADC doesn't switch the MUX in response to my command sent, but I think this is not a big problem in our case, since I guess the ADC input of AIN0 should also cause some result unequal to 0 (however, we're having only about 100mV of input there). Thanks for your explanation concerning the reading out of ADC values! Kind regards, Markus
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