user68989: I'm testing the AW9523B IO expander with an Arduino Nano. I can't get the device to be recognized.
Using I2C scanner to find all attached I2C devices.
I've connected AW9523B to the correct pins to the SDA/SCL pints of the Arduino, with 5K pullups. INTN is connected to GND.
An EEPROM is also connected on the bus. The EEPROM is recognized on the bus. I swapped the SDA/SCL pins just to make sure, and still AW9523B was not found on bus.
I've tried changing the AD0 and AD1 pins to no avail.
I have a 22uf capacitor on the VCC.
Changing the AD0 pin does change the default state of a connected LED, so I'm fairly confident the chip is not dead.
I've also tried the two example sketches from:

https://github.com/mrmx/AW9523B

Curious if anyone has gotten their AW9523B to work.

Updated Working Schematic


user71575: Transcribing and adding to the answer from the comments.
The AW9523B has a reset (RSTN) pin 23 which is internally pulled low by a 100K ohm resistor (i.e., default = reset). @Majenko suggests attaching a pull-up 10K ohm resistor to +5V (i.e., not reset) to enable the chip.
The data sheet schematics and section describing the reset function (pg14) seem to anticipate the RSTN pin being connected to an MCU GPO pin used to dynamically control the reset function.

68989: <p>I'm testing the AW9523B IO expander with an Arduino Nano. I can't get the device to be recognized.</p>
<p>Using I2C scanner to find all attached I2C devices.</p>
<p>I've connected AW9523B to the correct pins to the SDA/SCL pints of the Arduino, with 5K pullups. INTN is connected to GND.</p>
<p>An EEPROM is also connected on the bus. The EEPROM is recognized on the bus. I swapped the SDA/SCL pins just to make sure, and still AW9523B was not found on bus.</p>
<p>I've tried changing the AD0 and AD1 pins to no avail.</p>
<p>I have a 22uf capacitor on the VCC.</p>
<p>Changing the AD0 pin does change the default state of a connected LED, so I'm fairly confident the chip is not dead.</p>
<p>I've also tried the two example sketches from:</p>
<blockquote>
<p><a href="https://github.com/mrmx/AW9523B" rel="nofollow noreferrer">https://github.com/mrmx/AW9523B</a></p>
</blockquote>
<p>Curious if anyone has gotten their AW9523B to work.</p>
<p><a href="https://i.stack.imgur.com/AEPAM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AEPAM.png" alt="enter image description here" /></a></p>
<p><strong>Updated Working Schematic</strong>
<a href="https://i.stack.imgur.com/s99xR.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s99xR.jpg" alt="enter image description here" /></a></p>
 71575: <p>Transcribing and adding to the answer from the comments.</p>
<p>The <a href="https://cdn-shop.adafruit.com/product-files/4886/AW9523+English+Datasheet.pdf" rel="nofollow noreferrer">AW9523B</a> has a reset (RSTN) pin 23 which is internally pulled low by a 100K ohm resistor (i.e., default = reset). @Majenko suggests attaching a pull-up 10K ohm resistor to +5V (i.e., not reset) to enable the chip.</p>
<p>The data sheet schematics and section describing the reset function (pg14) seem to anticipate the RSTN pin being connected to an MCU GPO pin used to dynamically control the reset function.</p>
