Add touch sleep wakeup API

[P-R-O-C-H-Y]

Description of Change

As reported in the issue #7431 , the example DeepSleep/TouchWakeUp.ino is not working for ESP32-S2 and ESP32-S3. For these chips setting touch pad as wake up source needs different calls than ESP32.
So this new function works with all chips.
void touchSleepWakeUpEnable(uint8_t pin, touch_value_t threshold);

I have updated the example to work using this new function and made it work on all chips + updated docs.

Tests scenarios

Tested on ESP32, ESP32-S2 and ESP32-S3 with the updated TouchWakeUp.ino example.

Related links

Closes #7431

[SuGlider]

Very good, @P-R-O-C-H-Y !! I liked it!

[SuGlider]

I have tested it and it works better with this setup:

ESP32 -> Threshold = 40
S2/S3 -> Threshold = 1000

[P-R-O-C-H-Y]

For ESP32 we do have threshold 40.
But for S2/S3 it cannot be that small. Normal reading is higher that this value.
For S2 if the pad is touched, reading from touchRead is above 45k. For S3 its above 95k

[SuGlider]

I think that this is actually the delta, not the reading value itself.
It worked better (faster when touching the S2/S3 pad) when I changed it to 1,000
You can try it to check it.

[P-R-O-C-H-Y]

I have tested that a bit now, and managed to change it to 5000. That worked the best for me.
The 1000 was too much sensitive. I have attached the Dupont cable to the pin and it triggered even if I touched the rubber part of the cable, not the wire.
The 5000 triggers immediately I touch the wire :)

[SuGlider]

I have tested it adding 2 touch pin to the sketch:

touchSleepWakeUpEnable(T2,THRESHOLD);
touchSleepWakeUpEnable(T7,THRESHOLD);

ESP32 wakes up with both and reports the right pin.
S2/S3 only wakes up with the last Touch Pad used in touchSleepWakeUpEnable(), in the example above, it means the the SoC only wakes up when touching GPIO7.

[P-R-O-C-H-Y]

Do we need to add more pins for wakeup to the example?

[SuGlider]

Maybe... when it is an ESP32 only. Just to demonstrate it?!
Also, maybe, add commentaries about the limitation for the S2/S3 in the sketch?
Just a few suggestions.

[P-R-O-C-H-Y]

Added both :)

• Demontration for ESP32
• Comment in header about limitation

[SuGlider]

@P-R-O-C-H-Y - It seems there is a problem with S2/S3 when the sketch uses more than 1 touchpad for waking up. It works fine with ESP32, but not with S2/S3.

[P-R-O-C-H-Y]

@P-R-O-C-H-Y - It seems there is a problem with S2/S3 when the sketch uses more than 1 touchpad for waking up. It works fine with ESP32, but not with S2/S3.

@SuGlider I think S2/S3 can have only 1 touchpad for waking up. I have read about that in IDF docs. Maybe will be good if thats true to add a note in our docs too.

[P-R-O-C-H-Y]

@SuGlider Link to docs link

[SuGlider]

@SuGlider Link to docs link

Correct, I see that. This is valid for the S2 and S3. Please add a note to the documentation. Thanks!

[P-R-O-C-H-Y]

@SuGlider Docs updated with the note.

[rubenfrolic]

How do I get this to work in Arduino IDE? I tried to find a 2.0.5 dev version of the core. but can't find it. But need to update the core for this to work

[rubenfrolic]

Seems like it got it to work using the manual installation process: https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html