I2C Slave Address Match Wakeup
Posted: Tue Jun 30, 2026 7:06 pm
Hi, I was wondering if it is possible to do I2C slave address match wake-up from light-sleep as I do not see any existing API for this for the ESP32-S3.
I think there may be a workaround using GPIO pins to detect the low on the SDA line on a Start Condition. However, I am using GPIO 42 for SDA (Hardware restriction) rather than an RTC pin. GPIO 42 is attached to JTAG pin, so I can't seem to get GPIO wakeups to work from this. I am wondering if I may have to disable JTAG through efuses.
It may also be okay if have to switch to make a hardware change and switch to the RTC pins, but the existing API seems to support master only.
Let me know if there may be another way.
I think there may be a workaround using GPIO pins to detect the low on the SDA line on a Start Condition. However, I am using GPIO 42 for SDA (Hardware restriction) rather than an RTC pin. GPIO 42 is attached to JTAG pin, so I can't seem to get GPIO wakeups to work from this. I am wondering if I may have to disable JTAG through efuses.
It may also be okay if have to switch to make a hardware change and switch to the RTC pins, but the existing API seems to support master only.
Let me know if there may be another way.