My first ESP32 sensor solved a real problem, and now I'm building new projects every week

Published Sep 17, 2026, 3:30 PM EDT Ayush Pande is a PC hardware and gaming writer. When he's not working on a new article, you can find him with his head stuck inside a PC or tinkering with a server operating system. Besides computing, his interests include spending hours in long RPGs, yelling at his friends in co-op games, and practicing guitar. In my early ESP32 tinkering days, I’d only use the microcontroller to test with LEDs, resistors, and other circuitry components. In fact, writing simple C++ programs to perform basic tasks on the ESP32 was the farthest I’d go with this microcontroller. And even then, my entire motivation behind tinkering with ESP32 templates on Arduino IDE was to get some first-hand experience with coding. It wasn’t until I chanced upon the ESPHome Device Builder a few years ago that I figured I could try messing around with YAML code and a BME280 sensor module I’d bought for my Raspberry Pi eons ago. Not only did this experiment turn out successful, but I got so engrossed with it that I began populating my smart home with several other ESP32-powered sensor projects. A weather station seemed like a novice project, but it turned out to be quite useful The temperature metrics serve as reliable triggers for my automations On the surface, a DIY temperature-monitoring setup seems more like a beginner-friendly project that has no utility outside of getting newcomers accustomed to the ESP32’s quirks… and that’s low-key what I thought when I sat down to work on this project. However, I quickly changed my mind when I got the BME280 module hooked up to my ESP32. This might be a me problem, but it’s really hard to get the right temperature readings for the backwater town where I live. A general report of the surrounding city isn’t all that accurate, especially when the weather gets extremely turbulent. This wasn’t really a problem for me before I jumped down the Home Assistant rabbit hole. But since I wanted to create automation pipelines centered around precise temperature statistics, I couldn’t just import some random weather API and have it tweak my air-conditioning (and heating, depending on the season) using incorrect metrics. Now, my BME280 sensor isn’t the most accurate at measuring temps, as its precision value is ±1.0°C, but it’s still good enough for my automation projects, especially since it has a neat trick up its sleeve. Compared to the likes of DHT11, DHT22, and other cheap temperature sensors, the BME280 can refresh the weather statics in milliseconds, making it perfect for a DIY matrix LED display that updates its temp metrics every second. As for automations, I’ve already configured my HVAC setup to use the stats pulled by my BME280 + ESP32 combo. But my smart home also relies on humidity-sensing capabilities Besides the temperature metrics, the BME280 can also scan the humidity values. For the longest time, I simply had my matrix LED setup show the humidity numbers but didn’t know what to do with them. However, once I began working with PETG models, the humidity-sensing capabilities of my DIY weather station became a clutch. You see, PETG and a bunch of other filaments are hygroscopic, meaning they have a tendency to absorb moisture. This, in turn, can cause extra stringing when I turn them into tangible models, so I’d have to keep them as dry as possible. So, I created a second BME280 sensor specifically for my attic, which notifies me as soon as it detects the humidity level hitting the red zone. That way, I can unmount all the semi-used PETG filaments from my Elegoo CC2’s AMS module and keep them tucked inside a box full of silica gel. My successful weather station pushed me to presence detection sensors The right sensors work well with lighting automations One of the best aspects of ESP32 boards (and by extension, sensors) is their dirt-cheap pricing, and that’s pretty much why I was able to go out and buy a second one just for my 3D printing filaments. And well, I ended up grabbing a couple more ESP32-WROOM boards alongside whatever cool sensors met my fancy. This includes the HC-SR501, which I promptly used to build trigger action rules dependent on human presence. But since this sensor can detect movement, it causes my presence-based automations to fail every time I sit in a room for long periods. So, I ended up grabbing an mmWave to light up my hallways and rooms even when I’m not scampering all over the place. Connecting both sensors to my ESP32 was a cakewalk, and just like the BME280, I simply followed the official ESPHome docs to get everything running on Home Assistant. And things were never the same once I picked up a cheap box of sensors Since I already had a handful of sensors by this point, I decided to go all out and bought a sensor collection. I’ll admit that a couple of the sensors were low-quality ones, but being able to mess with over 30 modules more than made up for this issue. So far, I’ve had some neat automation pipelines configured from the KY-022 IR receiver, KY-037 (and KY-038) sound sensor, KY-002 vibration detector, and a bunch of other modules, and I’m planning to work with the laser, metal touch, and heartbeat sensors over the weekend. Brand AITRIP Connectivity Features UART, USB