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+# NoiseCard
+
+NoiseCard is an attempt to build a dead easy tool for monitoring ambient noise levels. The ultra-low-power microcontroller takes periodic decibel measurements while powered on, using blinking LEDs for indication. The circuit requires only a few milliwatts to run, enabling it to run off of direct solar power without a battery (though some large capacitors provide a small reserve).
+
+Ambient noise levels in populated areas, especially North America, can often exceed what is considered safe for our ears, with prolonged exposure leading to lasting impacts on our health. Through a tool like the NoiseCard, people can become more aware of the noisy environments they're living in (and potentially take action to reduce excess noise exposure).
+
+## Building the source
+
+You need:
+
+* [ChibiOS sources](https://www.chibios.org/dokuwiki/doku.php)
+* The arm-none-eabi GCC toolchain (through your distro or from [ARM developer](https://developer.arm.com/downloads/-/gnu-rm))
+* [GNU Make](https://www.gnu.org/software/make/)
+* [OpenOCD](https://openocd.org/) or another tool to program the microcontroller
+* [KiCAD](https://www.kicad.org/) if you wish to work with the hardware files
+
+Extract ChibiOS to a folder, edit the `Makefile` so CHIBIOS points to that folder, then run `make`.
+
+## Credits
+
+* [ESP32-I2S-SLM](https://hackaday.io/project/166867-esp32-i2s-slm) for a starting point with accurate decibel-measuring code.
+* [Qfplib](https://www.quinapalus.com/qfplib.html) for providing optimized floating-point code for the Cortex-M0+ microcontroller.
+* ChibiOS for providing an awesome RTOS and HAL that made firmware porting and device configuration a breeze.
+