ESP32S3 touch low-power wake-up issue

[chengoxuan]

import machine
from machine import TouchPad, Pin
import esp32

t = TouchPad(Pin(4))#Other pins have also been selected
t.config(500) # ESP32S3 is slightly larger and set at 25000
esp32.wake_on_touch(True)
machine.lightsleep() # put the MCU to sleep until a touchpad is touched
###################################################################################################
The function of turning on touch to enter low-power and touch wake-up is normal on the ESPWROOM32 board, but it is not normal on ESP32S3

1. If ESP32S3 does not has PSRAM, the touch function can sometimes be normal and sometimes abnormal, and it cannot enter low power consumption
2. If ESP32S3 have PSRAM, the touch function is normal, but it cannot enter low power consumption
   How can I use the touch wake-up function of ESP32S3 normally?

[sosi-deadeye]

I'm using a modified ESP32_GENERIC_S3 config for 16 MiB Flash and 8MiB SPIRAM_OCT compiled against ESP-IDF 5.1.
If I use esp32.wake_on_touch(True), then machine.lightsleep() does not work. It does not wakeup after given time in ms and the TouchPad does also nothing.

I thought I have used a GPIO which is not connected to RTC. But this was not the case. I tried GPIO1 and GPIO10.

[skrat]

I have the same issue, using esp-idf 5.4.2 and M5 uiflow's micropython 1.25, on M5 PaperS3 board.

[shariltumin]

The touch functionality on the ESP32-S3 is different from that on the ESP32, esp32.wake_on_touch() does not currently work on ESP32-S3 boards.

Instead, you might want to use esp32.wake_on_ext0(). Please try this:

from machine import Pin, lightsleep
from time import sleep_ms
import esp32

# Use an RTC-capable pin on the S3 - GPIO1, GPII10
trigger = 10 # 1, 10
# hold=True parameter is critical!
wake_pin = Pin(trigger, Pin.IN, Pin.PULL_UP, hold=True)
esp32.wake_on_ext0(pin=wake_pin, level=esp32.WAKEUP_ALL_LOW)

while True:
    print(f"Going to light sleep. Touch Pin{trigger} to GND to wake up")
    sleep_ms(200)  # Pause to flush prints
    lightsleep()
    print("Woke up")
    sleep_ms(500)

The REPL output is via USB serial, so the output can be erratic.

[shariltumin]

Are you sure about Pin36?

>>> from machine import Pin
>>> Pin(36)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid pin
>>> Pin(48)
Pin(48)

But, Pin48 is not RTC enabled Pin.

[skrat]

It is on pin 48, and yes, it is not RTC enabled, therefore only wake up from lightsleep is possible on the M5 PaperS3 board.

See https://github.com/felmue/MyM5StackExamples/blob/main/M5PaperS3/LightSleepTouchWakeup/LightSleepTouchWakeup.ino

I'm not sure how to call gpio_wakeup_enable from within mpy's esp32 module, it doesn't seem to be there.

[shariltumin]

Try any unused pin below 21 inclusive.

[skrat]

Why tho? Have you seen this? https://github.com/felmue/MyM5StackExamples/blob/main/M5PaperS3/LightSleepTouchWakeup/LightSleepTouchWakeup.ino#L65-L68

It also matches the schematic, the pin is GPIO pin 48, no RTC

[shariltumin]

I cannot find GPIO48 in the schematic.

Pin#48 on the board is connected to GPIO42/MTMS. The board pin number is not the same as GPIO number.

I don't know Arduino and have never programmed with it. You should ask the author of the code.