[{"data":1,"prerenderedAt":84},["ShallowReactive",2],{"project-air-quality-monitor":3},{"id":4,"title":5,"body":6,"description":72,"extension":73,"meta":74,"navigation":79,"path":80,"seo":81,"stem":82,"__hash__":83},"projects/projects/air-quality-monitor.md","Air quality monitor wearable",{"type":7,"value":8,"toc":66},"minimark",[9,14,18,21,29,32,42,45,51,62],[10,11,13],"h2",{"id":12},"description","Description",[15,16,17],"p",{},"I worked as an embedded software engineer for many years and always thought about learning PCB design, now I finally got to it!",[15,19,20],{},"I wanted to build a wearable device that can measure the air quality in real-time and send warnings when it's out of the safe range (what the safe range is and of what, is still to be defined..).\nI chose a low power, bluetooth capable microcontroller: the nRF52832, and selected this interesting sensor from Bosch: the BME688, that can measure temperature, humidity, pressure and air quality.",[15,22,23],{},[24,25],"img",{"alt":26,"src":27,"width":28},"Schematic","/images/air-ctrl/mcu-schematic.png",550,[15,30,31],{},"I fired up KiCAD and started with the electrical schematic which went pretty smoothly, I read the datasheets and found other projects using similar components, so I could copy the circuits and put them together.\nThen moved to the layout which was the most challenging part for me, placing everything in such a small space (35x35mm), while following best practices and all the constraints is not easy, I started over twice...",[15,33,34,38],{},[24,35],{"alt":36,"src":37,"width":28},"Layout front","/images/air-ctrl/front-layout.png",[24,39],{"alt":40,"src":41,"width":28},"Layout back","/images/air-ctrl/bottom-layout.png",[15,43,44],{},"Now the PCB is ordered and while I am waiting for it I started working on the firmware. Will use Zephyr RTOS and the nRF52832 SDK.",[15,46,47],{},[24,48],{"alt":49,"src":50,"width":28},"PCB","/images/air-ctrl/pcb.png",[15,52,53,54,61],{},"The project is open source and available on GitHub, to see the current status check ",[55,56,60],"a",{"href":57,"rel":58},"https://github.com/saraelhark/air-ctrl",[59],"nofollow","here",".",[10,63,65],{"id":64},"to-be-continued","To Be Continued",{"title":67,"searchDepth":68,"depth":68,"links":69},"",2,[70,71],{"id":12,"depth":68,"text":13},{"id":64,"depth":68,"text":65},"A wearable air quality monitor built from scratch — custom PCB designed in KiCAD with nRF52832 microcontroller and Bosch BME688 sensor. Firmware in Zephyr RTOS.","md",{"date":75,"status":76,"label":77,"image":50,"slug":78,"website":57},"October 2025","Development 🛠","Hardware, Software","air-quality-monitor",true,"/projects/air-quality-monitor",{"title":5,"description":72},"projects/air-quality-monitor","qkCrcaLfwhomDyKlGp6EIst2AKaQEWnAk_6Lc3JnqCg",1772290576848]