{"id":557098,"date":"2026-03-24T08:37:11","date_gmt":"2026-03-24T08:37:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/557098\/"},"modified":"2026-03-24T08:37:11","modified_gmt":"2026-03-24T08:37:11","slug":"acoustic-drone-detection-on-the-cheap-with-esp32","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/557098\/","title":{"rendered":"Acoustic Drone Detection On The Cheap With ESP32"},"content":{"rendered":"

We don\u2019t usually speculate on the true identity of the hackers behind these projects, but when [TN666]\u2019s accoustic drone-detector crossed our desk with the name \u201cBatear\u201d<\/a>, we couldn\u2019t help but wonder\u2013 is that you, Bruce? On the other hand, with a BOM consisting entirely of one ESP32-S3 and an ICS-43434 I2S microphone, this isn\u2019t exactly going to require the Wayne fortune to pull off. Indeed, [TN666] estimates a project cost of only 15 USD, which really democratizes drone detection.<\/p>\n

\"\"<\/a>It\u2019s not a tuba\u2013\u00a0 Imperial Japanese aircraft detector being demonstrated in 1932. Image Public Domain via rarehistoricalphotos.com<\/p>\n

The key is what you might call \u2018retrovation\u2019\u2013 innovation by looking backwards. Most drone detection schema are looking to the ways we search for larger aircraft, and use RADAR. Before RADAR there were acoustic detectors, like the famous Japanese \u201cwar tubas\u201d that went viral many years ago. RADAR modules aren\u2019t cheap, but MEMS microphones are\u2013 and drones, especially quad-copters, aren\u2019t exactly quiet. [TN666] thus made the choice to use acoustic detection in order to democratize drone detection.<\/p>\n

Of course that\u2019s not much good if the ESP32 is phoning home to some Azure or AWS server to get the acoustic data processed by some giant machine learning model.\u00a0 That would be the easy thing to do with an ESP32, but if you\u2019re under drone attack or surveillance it\u2019s not likely you want to rely on the cloud. There are always privacy concerns with using other people\u2019s hardware, too. [TN666] again reached backwards to a more traditional algorithmic approach\u2013 specifically Goertzel filters to detect the acoustic frequencies used by drones. For analyzing specific frequency buckets, the Goertzel algorithm is as light as they come\u2013 which means everything can run local on the ESP32. They call that \u201cedge computing\u201d these days, but we just call it common sense.<\/p>\n

The downside is that, since we\u2019re just listening at specific frequencies, environmental noise can be an issue. Calibration for a given environment is suggested, as is a foam sock on the microphone to avoid false positives due to wind noise. It occurs to us the sort physical amplifier used in those \u2018war tubas\u2019 would both shelter the microphone from wind, as well as increase range and directionality.<\/p>\n

[TN] does intend to explore machine learning models for this hardware as well; he seems to think that an ESP32-NN or small TensorFlow Lite model might outdo the Goertzel algorithm. He might be onto something, but we\u2019re cheering for Goertzel on that one, simply on the basis that it\u2019s a more elegant solution, one we\u2019ve dived into before<\/a>. It even works on the ATtiny85,<\/a> which isn\u2019t something you can say about even the lightest TensorFlow model.<\/p>\n

Thanks to [TN] for the tip. Playboy billionaire or not, you can send your projects into the tips line<\/a> to see them some bat-time on this bat-channel.<\/p>\n","protected":false},"excerpt":{"rendered":"We don\u2019t usually speculate on the true identity of the hackers behind these projects, but when [TN666]\u2019s accoustic…\n","protected":false},"author":2,"featured_media":557099,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[49,48,61],"class_list":{"0":"post-557098","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-technology","8":"tag-ca","9":"tag-canada","10":"tag-technology"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/557098","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=557098"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/557098\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/557099"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=557098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=557098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=557098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}