GoKawiilIf you live in Europe the northern hemisphere, you are probably suffering through a heat wave right now. Let's do something to bring back some chill, using iroh.
The previous ESP32 examples demonstrated echo protocols. But typically ESP32s are used for more than just echoing data; you use an ESP32 as a cheap means to read sensors and drive actuators.
So we are going to write a very simple end-to-end example using an ESP32 to measure temperature and control a fan. Unlike most IoT devices, there won't be any cloud component. Just a tiny website that you can use from anywhere in the world using any browser that supports WebAssembly.
As the base, we are going to use an ESP32-WROVER devkit with 4 MiB of PSRAM, so we have all of iroh's networking capabilities available, including a relay connection, and remote control it from anywhere in the world. You can also use a M5StickC-Plus2, but you will have to adapt the GPIO pins.
As the first step, we are going to copy over an echo example from iroh-esp32-examples. We will use server-esp32-psram for the ESP32 binary.
For the client side we just use client , it runs on a desktop PC and is as vanilla as it gets.
This is going to be a smart fan example, so we just rename server-esp32-psram to server-smart-fan , and client to smart-fan-cli .
Note that we need different toolchains and want to keep the option to use a patch of iroh for the ESP32 variant, so the two directories are completely separate Rust projects. We do not use a workspace.
Initial state
Let's try it out once before we do modifications. cargo run on the server project will search for an ESP32 connected via USB and flash it. So we just connect our ESP32 with a USB-C cable.
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