I went down a rabbit hole trying to add a “favicon” (Web page icon) to an ESP32 web server project.
No one seems to have a complete answer, so here you go!
UPDATE: After I clicked “Publish” on the original version of this article, I started running in to all sorts of problems with my ESP32.
This sent me even deeper in to the rabbit hole, but I ultimately found a good solution.
Here is a step-by-step walk-through (UPDATED).
Did you know that the ESP32 has a built-in user LED and Utility Button? No need to build a simple circuit to do testing.
The ESP32 is an amazing Arduino device that has lots of GPIO pins, plenty of CPU and memory capacity, as well as built-in WiFi and Bluetooth, and many other features.
| Interface | Description |
|---|---|
| ■ Power LED | Red when power is on |
| ■ User LED | Blue when activated by pulling GPIO2 HIGH. |
| ■ EN Button | “Enable”, normally HIGH. Pushing the button pulls LOW, which reboots. |
| ■ BOOT Button | When used with “EN”, causes the device to boot in to programming mode.
Normally GPIO0 is HIGH (Normal boot mode). Pushing the button pulls GPIO0 LOW (Enter programming / download mode). However, after the device boots normally, the BOOT button can be used to send input to GPIO0. |