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AD7795 hangs periodicly

Question asked by tim@etc.be on Jun 10, 2015
Latest reply on Jun 24, 2015 by jcolao

We use the AD7795 to readout 3 resistor bridges. These are connected between
AIN1, AIN2 and AIN3. The reference is taken from an external reference of 1V.

We let the measurements run continiously. After an uncertain time the AD7795
hangs and only returns values of 0. Now the device consumes much more current,
up to 700mA. The only solution is to remove the power from the module and
restart the AD7795. After this it will work fine for minutes (mostly 10 to 30
minutes).
We tried to use the polling method by reading the status register and also by
checking the DOUT line status.
With both methods we have this problem.

These are our settings:
MY_AD7794_CONFIG_H       AD7794_CRH_BIAS_OFF | AD7794_CRH_UNIPOLAR | AD7794_CRH_GAIN_64
MY_AD7794_CONFIG_L        AD7794_CRL_REF_IN1 | AD7794_CRL_REF_DETECT | AD7794_CRL_BUFFER_ON
MY_AD7794_MODE_H          AD7794_MRH_AMP_CM
MY_AD7794_MODE_L           AD7794_MRL_CLK_INT_NOOUT | AD7794_MRL_UPDATE_RATE_16_7_HZ_80DB

What can we do wrong? Do you need more details?

Kind regards Tim Adriaensens

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