web.esphome.io serial log for sleeping devices

[hmorkemo]

Describe your request

I'm using web.esphome.io to install a project on a device that will be in deep sleep most of the time.
The device doesn't use WiFi, so I can't use the wireless log, so I have to use the usb serial log. And WiFi is available too late to help with the boot sequence debugging anyway.
When the device enters deep sleep, web.esphome.io drops the serial connection, so the wakeup sequence will be unavailable.
Terminal emulators keep listening to the port even if the device is dead for a while.
It would be very helpful if web.esphome.io could do this as well! Debugging startup sequences for a non-WiFi device is very cumbersome today.

Why the uncertainty?

No response

Use cases

It will be used for debugging startup sequences for devices waking up from deep sleep.

What areas might this affect?

No response

Anything else?

No response

[ssieb]

What ESP board are you using?

[hmorkemo]

ESP32-C3. It's the only type I've been using deep sleep with so far. I have other projects in the pipeline where I'll most likely be using ESP32-S3 or other boards. Do the different boards behave in different ways regarding deep sleep and web.esphome.io serial logging?

[ssieb]

You'll need to use a USB uart adapter on the uart pins and change the logger hardware uart.
The newer chips do the USB serial as "software", so the interface goes away when they deep sleep or reboot.

[hmorkemo]

Ok...
But when I use a Windows terminal emulator, such as Tera Term, it listens to the port. Here's an example log from a deep sleep+wakeup session:

[I][deep_sleep:061]: Beginning sleep
[I][deep_sleep:063]: Sleeping for 43200000000us
[D][main:027]: on_shutdown
[0;32m[I][logger:121]: Log initialized
[I][app:073]: Running through setup()
[C][component:173]: Setup spi took 1ms
[C][component:173]: Setup preferences took 0ms
[D][spi_device:393]: mode 0, data_rate 8000kHz
[C][component:173]: Setup sx127x took 19ms
[C][component:173]: Setup template.sensor took 0ms
[C][component:173]: Setup template.sensor took 0ms
[C][component:173]: Setup switch took 0ms
[D][switch:026]: 'led1' Turning OFF.
[D][switch:065]: 'led1[C][sx127x:403]: SX127x:
[C][sx127x:404]:   CS Pin: GPIO5
[C][sx127x:405]:   RST Pin: GPIO4
[C][sx127x:406]:   DIO0 Pin: GPIO6
[C][sx127x:411]:   Auto Cal: TRUE
  Frequency: 433920000 Hz
  Bandwidth: 125000 Hz
  PA Pin: BOOST
  PA Power: 17 dBm
  PA Ramp: 40 us
[C][sx127x:432]:   Modulation: LORA
etc.

It loses some bits, so it's not perfect. It missed the gpio pin that woke it up, and it also got confused around turning led1 on, and probably some more. This might be because the usb serial port has to be "started"
But it's much better than nothing. (I guess there may be better terminal emulators out there that will capture everything.)
The problem with this approach is that I have to connect + disconnect both web.esphome.io and teraterm all the time.

[ssieb]

This might be because the usb serial port has to be "started"

Exactly, it has to detect the serial port coming back and then open it again.

Why do you need the esphome web open?

[hmorkemo]

I prefer to keep win.esphome.io open because I have to use it for uploading new versions while debugging. The device doesn’t have a WiFi connection.