Not getting interrupts from capacitive button about micropython-pcf8575

[mcauser]

The TTP223 module as pictured has two solder-bridge pads on the back labelled A and B.
These determine whether a touch drives the OUT pin HIGH or LOW, and whether it's momentary or latching (stays on until pressed again).
https://github.com/mcauser/micropython-ttp223#trigger-mode

On my TTP223 both A and B are no bridged, which means: Momentary, output HIGH (when pressed).

The PCF8575's interrupt should fire on any rising or falling edge when the pin is in input mode.

Here's a working example on my TinyPICO.

TinyPICO	PCF8575	TTP223
3V3	VCC	VCC
GND	GND	GND
22	SCL
21	SDA
5	INT
	P0	OUT

import pcf8575
from machine import Pin, I2C
i2c = I2C(scl=Pin(22), sda=Pin(21))
pcf = pcf8575.PCF8575(i2c, 0x20)

# set all pins as inputs (HIGH)
pcf.port = 0xffff

# make sure the pin is being pulled up as the PCF int will pull it LOW when it fires
p5 = Pin(5, Pin.IN, Pin.PULL_UP)

print(p5.value())
# shows 1 (high)

print(pcf.port)
# shows 65534 or 0xFFFE
# meaning all pins are HIGH except for P0 which is being pulled LOW by the TTP223

# simple interrupt handler that prints the INT pin value and the PCF pin values
def handler(p):
	print(f'Pin5: {p5.value()}, Port: {pcf.port}')

# trigger on rising and falling edges
p5.irq(trigger=Pin.IRQ_RISING|Pin.IRQ_FALLING, handler=handler)

# press and hold and the TTP223 button prints
Pin5: 0, Port: 65535
Pin5: 1, Port: 65535

# release and the TTP223 button prints
Pin5: 0, Port: 65534
Pin5: 1, Port: 65534

# switch int off
p5.irq(None)

# trigger on falling edge only
p5.irq(trigger=Pin.IRQ_FALLING, handler=handler)

# pressing the TTP223 button prints
# Pin5: 0, Port: 65535

# releasing the TTP223 button prints
# Pin5: 0, Port: 65534

[mcauser]

Make sure you pull Pin 15 HIGH for it to detect when the PCF pulls it LOW on INT.

On the ESP8266, GPIO15 is usually pulled to GND as BOOT fails if it's pulled HIGH.
(Your script can set it HIGH after booting, but you shouldn't use a hardware pull up (resistor) to be safe)
https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/

Maybe it's better if you use a different GPIO for the INT. GPIO0 and GPIO2 are normally pulled HIGH and driven LOW.

[Vacant0mens]

If I'm not using SPI, I could use pin 14 for my interrupts, right?

[mcauser]

Sure can. If not using SPI, it's just a regular GPIO pin.

[Vacant0mens]

That worked! thank you!
Seems like using the wrong pin is the bane of my existence.