About

ESP32S3 module that acts as a webserver and keyboard. Whenever someone sends an HTTP request to the server it'll emulate an F24 keypress. Used to wake up a laptop which doesn't respond to Wake-on-LAN and out of reach by other wireless means (e.g. like a 2.4 GHz wireless mouse or similar).

• Written for LILYGO T-Dongle-S3
• Use PlatformIO plugin VS Code to build
• Copy wifi_setup.h.sample to wifi_setup.h and configure SSID and password in the header file before building
• To upload plug the device into a USB port while holding the button on it
• To run the code replug it without holding the button
• To run pio executable in VS Code run Open PlatformIO Core CLI from the command palette
• To build and upload project run pio run --target upload
• Then run pio run --target monitor to see the output on serial

Android

Discovering the board on Windows and macOS works almost always and curl wake-on-esp32s3.local goes through. Android is a mixed bag. Here are some ways to try and debug what can make the address not to resolve.

I've tested this on a Samsung A52s 5G with Android 12 (latest updates as far as I know).

• From a specific Android version and upwards .local addresses should be resolved properly (in theory)
• Private DNS settings can have an effect whether the address resolves or not
• However on my LAN the address wouldn't resolve no matter what my private DNS setting was (off, automatic, or a specific resolver, dnsforge.de in my case)
• Yet again, on another LAN the address only resolved when I disabled private DNS
• Checking what kind of DNS server is used to resolve things is kind of difficult, but here is a method
  • Connect to the phone with adb
  • Run dumpsys connectivity | grep -i dns
  • Give the output to some AI chat model to format and analyze and see what's in there
  • Re-run it after switching private DNS settings
• Could also prove useful to check these
  • settings list global | grep -i dns
  • dumpsys connectivity | grep -i dns | grep 'WIFI CONNECTED'
  • dumpsys connectivity | grep -i dns | grep 'WIFI CONNECTED' | grep -o 'DnsAddresses.*Domains'
• Using something like Termux to see DNS settings might prove useless, since they might use custom DNS resolver settings
• Although, in theory it should not matter since .local resolving should bypass DNS servers (to my understanding)
• Finally, check your browser whether it can resolve http://wake-on-esp32s3.local

Note: written about my experiences regarding this here.

TODO

• Implement simple logging onto the TFT (need to handle overflowing text with println, e.g. calculate how many lines with in certain orientation and keep a few line buffers)
• Handle different REST requests to do certain stuff (enabled/disable TFT using POST and DELETE, etc.)
• Print MAC address or IP to TFT (since .local might not work)
• Maybe listen to a multicast message to wake up on instead of HTTP