Posts tagged with “platformio”

USB Power Meter

USB Power Meter

Casually put together a small but rather fun project. I got curious about how much power my DIY gadgets actually consume—and at the same time, I wanted to check the real capacity of those AliExpress batteries. Sure, you could use a multimeter, but then you’d have to rig up some janky setup to wedge it into a USB cable, plus keep unplugging it whenever you need it elsewhere. And devices with microcontrollers have fluctuating power draw depending on their operating mode. So I built myself a dedicated device.
Read more...
Low-Power LCD Clock with ESP32-C3 and Custom HT1621 Driver

Low-Power LCD Clock with ESP32-C3 and Custom HT1621 Driver

I built another clock. Not because I don’t already have clocks—I have plenty, including a few homemade ones. But if you start some big, complicated project, there’s a good chance you won’t finish it… even if you’ve got the long New Year holidays ahead.
Read more...
URU Card - minimal FIDO2 implementation with Arduino

URU Card - minimal FIDO2 implementation with Arduino

Finally, a working BLE-based FIDO2 authenticator on Arduino! The URU Card project now supports basic credential creation and authentication via ESP32. Still early-stage (with hardcoded keys for now), but it’s enough to pass WebAuthn tests in Windows—and it’s open for everyone to try and build on.

Read more...
Comparison of CO2 sensors MH-Z19B and CCS811

Comparison of CO2 sensors MH-Z19B and CCS811

I hooked up both the MH-Z19B and CCS811 CO₂ sensors side by side and logged data for a full week. The results? They mostly follow the same trends—but actual readings vary wildly, sometimes by 1000+ ppm. Which one’s accurate? Hard to say without a calibrated reference…

Read more...
Carbon Dioxide Sensor CCS811

Carbon Dioxide Sensor CCS811

Picked up a CJMCU-811 CO₂ and air quality sensor to compare it with my go-to MH-Z19B. It’s smaller, cheaper, uses I2C, and reacts super fast (you can literally breathe on it and watch the values change). One of my two units didn’t work, though—so quality might be hit or miss.

Read more...
Carbon Dioxide Sensor MH-Z19b - Part 2 - Software

Carbon Dioxide Sensor MH-Z19b - Part 2 - Software

In Part 2 of my CO₂ sensor project, I set up the MH-Z19b with Arduino and ESP8266 using PlatformIO. Added WiFi-based configuration with my own WiFiConfig library, and used RecurringTask to keep everything responsive without blocking the loop. It’s simple, wireless, and super easy to tweak from your browser!

Read more...
ESP8266 - simple configuration over WiFi

ESP8266 - simple configuration over WiFi

While building my CO2 sensor, I wanted to manage the device over WiFi—no buttons, no cables. So, I made a sleek web-based config panel using VueJS and Tailwind CSS, all running right on the ESP8266. Here’s how I replaced manual setup with a modern, async, file-based config system.

Read more...
Carbon Dioxide Sensor MH-Z19b - Part 1 - Hardware design

Carbon Dioxide Sensor MH-Z19b - Part 1 - Hardware design

Ever feel like the air in your room gets a bit… stale? I picked up a cheap MH-Z19b CO2 sensor and built a simple home air quality monitor using an ESP8266 and some DIY magic. Here’s how I prototyped it (twice!) and got it up and running with WiFi and colorful LED alerts.

Read more...