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5 The NXP PCA9571 chip is an 8-bits I²C output expander.
8 https://www.nxp.com/products/analog/interfaces/ic-bus/ic-general-purpose-i-o/remote-8-bit-general-purpose-outputs-for-1-mhz-i2c-bus:PCA9571
9 https://www.nxp.com/docs/en/data-sheet/PCA9571.pdf
15 The logic analyzer used was a Hobby Components HCTEST0006 (at 2 MHz):
18 ----------------------
26 The sigrok command line used was:
28 sigrok-cli -d fx2lafw -c samplerate=2mhz --time <time> \
29 --channels 'D0=SDA,D1=SCL' -o <filename.sr>
32 This is a set of example captures of NXP PCA9571 I/O accesses.
34 Three traces are included:
36 - pca9571_simple.sr: a simple output write operation.
38 - pca9571_sequence.sr: 64 consecutive write operations.
40 - pca9571_warning.sr: this produces a warning because the first read value
41 is different from the expected one (the PCA9571 start-up 8-bits port
42 status is high logic level 0xFF). This may occur if the first monitored
43 operation is a read operation and the PCA9571 is not in its default state
44 or if the PCA9571 reboots during the monitoring.