{"product_id":"m5stack-mini-pdm-unit-spm1423-u089","title":"M5Stack Mini PDM Unit – SPM1423 MEMS Microphone | U089","description":"\u003cp\u003e\u003cvideo controls muted playsinline style=\"width:100%;height:auto;border-radius:8px;\"\u003e\u003csource src=\"https:\/\/m5stack.oss-cn-shenzhen.aliyuncs.com\/video\/Product_example_video\/Unit\/PDM.mp4\" type=\"video\/mp4\"\u003e\u003c\/video\u003e\u003c\/p\u003e\u003cp\u003eThe M5Stack Mini PDM Unit captures digital audio for sound-event detection, spectrum analysis, voice interfaces, data logging, and wearable prototypes. Its SPM1423 MEMS microphone outputs a pulse-density-modulated bitstream through clock and data lines, avoiding a long analog microphone path. A compatible host must generate the PDM clock and decimate the stream into PCM samples. Useful recordings depend on clock configuration, filtering, buffer management, acoustic-port placement, enclosure design, vibration isolation, calibration, and privacy requirements.\u003c\/p\u003e\u003ch2\u003eMini PDM Unit: Core Functions and Control\u003c\/h2\u003e\u003ch3\u003eCapture Sound with the SPM1423 MEMS Microphone\u003c\/h3\u003e\u003cp\u003eThe digital microphone converts acoustic pressure into a PDM bitstream for a host with a compatible PDM or I2S receive path.\u003c\/p\u003e\u003ch3\u003eConvert PDM Data into PCM Audio\u003c\/h3\u003e\u003cp\u003eThe host supplies the clock, collects the one-bit stream, and applies decimation and filtering to generate conventional samples.\u003c\/p\u003e\u003ch3\u003eDesign the Acoustic Port Carefully\u003c\/h3\u003e\u003cp\u003eThe microphone opening must remain unobstructed because airflow, vibration, cavities, and nearby speakers affect the signal.\u003c\/p\u003e\u003ch2\u003eMini PDM Unit Applications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eDigital audio recording prototypes\u003c\/li\u003e\n\u003cli\u003eSound-event detection\u003c\/li\u003e\n\u003cli\u003eSpectrum and frequency analysis\u003c\/li\u003e\n\u003cli\u003eWearable voice interfaces\u003c\/li\u003e\n\u003cli\u003eMachine-noise experiments\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eHow to Integrate the Mini PDM Unit\u003c\/h2\u003e\u003col\u003e\n\u003cli\u003eConnect the cable to host pins supporting PDM or compatible I2S reception.\u003c\/li\u003e\n\u003cli\u003eConfigure clock, decimation, sample rate, channel mapping, and buffers.\u003c\/li\u003e\n\u003cli\u003eKeep the acoustic opening clear and isolate it from airflow and vibration.\u003c\/li\u003e\n\u003cli\u003eRecord a known source and verify level, clipping margin, and noise floor.\u003c\/li\u003e\n\u003cli\u003eHandle buffer overruns, clock loss, storage limits, and privacy requirements.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch2\u003eMini PDM Unit Deployment Notes\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eThe output is a PDM bitstream, not an analog voltage.\u003c\/li\u003e\n\u003cli\u003eA compatible peripheral or software pipeline must convert PDM to PCM.\u003c\/li\u003e\n\u003cli\u003eEnclosure acoustics, airflow, vibration, and mounting affect recordings.\u003c\/li\u003e\n\u003cli\u003eAbsolute sound-pressure measurements require calibration.\u003c\/li\u003e\n\u003cli\u003eAudio recording may be subject to privacy and consent laws.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eMini PDM Unit Development Resources\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/docs.m5stack.com\/en\/products\/sku\/U089\" target=\"_blank\" rel=\"nofollow noopener noreferrer\"\u003eM5Stack Mini PDM Unit Official Documentation\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/uiflow2.m5stack.com\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\"\u003eUiFlow2 Development Environment\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/docs.arduino.cc\/software\/ide\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\"\u003eArduino IDE\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"LogicBoundless","offers":[{"title":"Default Title","offer_id":49240346755287,"sku":"LB-M5-U089","price":6.9,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0801\/8952\/2135\/files\/1_43e7feb6-36b3-4da9-88d3-ba06318e980f.jpg?v=1783243273","url":"https:\/\/logicboundless.com\/products\/m5stack-mini-pdm-unit-spm1423-u089","provider":"LogicBoundless","version":"1.0","type":"link"}