PmodCDC1™ Reference Manual
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about 12 fF). Users can choose to either detect when the output of a channel crosses its threshold by “watching”
its respective output pin on header J2 for a high voltage or can get more specific information by querying the
device through the I²C interface.
2.1 Example: Continuous Read with Default Settings
A communication transmission example taking advantage of continuous read capability and reporting the contents
of the Status (address 0x00), most recent Channel 1 and Channel 2 data, and average Channel 1 and Channel 2
data registers, is shown below. The bit names are taken from the Analog Devices datasheet and are defined after
the table.
Status Register Bit Values
PwrDown = 1 indicates that the part is in a power-down
DacStep2 = 0 indicates that the Channel 2 CAPDAC value was changed after the last CDC
conversion as part of the auto-DAC function. The bit value is updated after each finished CDC
converion on this channel.
OUT2 = 1 indicates that the Channel 2 data (CIN2 capacitance) crossed the threshold, according
to the selected comparator mode of operation. The bit value is updated after each finished CDC
conversion on this channel.
DacStep1 = 0 indicates that the Channel 1 CAPDAC value was changed after the last CDC
conversion as part of the auto-DAC function. The bit value is updated after each finished CDC
converion on this channel.
OUT2 = 1 indicates that the Channel 1 data (CIN1 capacitance) crossed the threshold, according
to the selected comparator mode of operation. The bit value is updated after each finished CDC
conversion on this channel.
C1/C2 = 0 indicates that the last finished CDC conversion was on Channel 1. C1/C2 = 1 indicates
that the last finished CDC conversion was on Channel 2.
RDY2 = 0 indicates a finished CDC conversion on Channel 2. The bit is reset back to 1 when the
Channel 2 data register is read via the serial interface or after a part reset or power-up.
RDY1 = 0 indicates a finished CDC conversion on Channel 1. The bit is reset back to 1 when the
Channel 1 data register is read via serial interface or after a part reset or power-up.
The bits of the status register are defined in their own table (from the Analog Devices datasheet).
The last four bits of each data set are not part of the 12-bit data conversion and so are either 0's or don't cares (X)
