Hi,
I'm using this I/O-Expander to drive some LEDs on a measuring device. The LEDs are set up in a row to show the measured value on a scale. It works perfectly using a uC to send the data over the I2C bus.
The Issue:
When restarting the device some LEDs sometimes randomely flahed at the very beginning of the bootup. The PCA9535 is getting a 3.3V (Vcc) Power Support immediately after the device is turned on.
Unfortunately, I can't handle that effect in the firmware bc it happend before the firmware even start to initialize the I/O-Expander.
Below is the circuit that I'm using to control the LEDs:
I hope you can help me solving this issue by eliminating the described effect on bootup! Thanks a lot!