{"product_id":"adafruit-pdm-mems-microphone-breakout","title":"Adafruit PDM MEMS Microphone Breakout","description":"\u003cp\u003eAn exotic new microphone has arrived, a \u003cstrong\u003ePDM MEMS Microphone\u003c\/strong\u003e!\u003c\/p\u003e\n\u003cp\u003ePDM is the 'third' kind of microphone you can integrate with electronics, apart from analog or I2S. These microphones are very commonly used in products, but are rarely seen in maker projects. Still, they have some benefits so Adafruit thought they'd offer a breakout for the shop.\u003c\/p\u003e\n\u003cp\u003eThe first thing to note is that this sensor does not provide an 'analog' output like many of our electret microphone assemblies. So it's great for chips that do not have analog inputs. Secondly, the digital interface is a very simplistic \u003cstrong\u003ep\u003c\/strong\u003eulse \u003cstrong\u003ed\u003c\/strong\u003eensity \u003cstrong\u003em\u003c\/strong\u003eodulation output. It's digital but its \u003cem\u003enot\u003c\/em\u003e PWM and it's \u003cem\u003enot\u003c\/em\u003e I2S. You will need to make sure your chip has a PDM interface - most 32-bit processors these days do!\u003c\/p\u003e\n\u003cp\u003ePDM is a little like 1-bit PWM. You clock the mic with a 1 MHz - 3 MHz clock rate, and on the data line you'll get a square wave out that syncs with the clock. The data line with be 0 or 1 logic output, with the square wave creating a \u003cem\u003edensity\u003c\/em\u003e that when averaged will result in the analog value out.\u003c\/p\u003e\n\u003cp\u003eThere's a few ways to manage these mics:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eYour chip comes with a hardware peripheral and library that does all the data managing at high speed, collects samples, applies a filter and gives you an analog value (Ideal!)\u003c\/li\u003e\n\u003cli\u003eYour chip comes with a hardware peripheral that gives you values, then it is up to you to perform the decimation\/filtering. (We have some example code for this on the ATSAMD21 chipset)\u003c\/li\u003e\n\u003cli\u003eYour chip does not come with a hardware peripheral but you're pretty clever and come up with a way to make it work (\u003ca href=\"https:\/\/curiouser.cheshireeng.com\/2015\/01\/21\/pdm-in-attiny85-source-code\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eSee this example for the ATtiny85\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003eYou generate the high speed clock, then add an analog filter on the data line, and read the analog value (A hack, but works!)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eEither way you decide to go, make sure you have a handle on what support you get with your platform, as these chips are a little tricky!\u003c\/p\u003e\n\u003cp\u003eEach order comes with one fully assembled and tested microphone, and a little header to solder on for breadboard-compatibility. \u003ca href=\"http:\/\/learn.adafruit.com\/adafruit-pdm-microphone-breakout\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eCheck out the full guide for wiring details, schematics, example code, datasheet and more!\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTECHNICAL DETAILS\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/learn.adafruit.com\/adafruit-pdm-microphone-breakout\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eWiring, schematics, example code, datasheets, Fritzing and more in the product tutorial!\u003c\/a\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eVoltage Range: 1.8-3.3V\u003c\/li\u003e\n\u003cli\u003eClock rate: 1 - 3.25 MHz\u003c\/li\u003e\n\u003cli\u003eCurrent draw: 0.6mA\u003c\/li\u003e\n\u003cli\u003eSNR: 61 dB\u003c\/li\u003e\n\u003cli\u003eSensitivity: ~-26 dBFS\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eProduct Dimensions: 14.0mm x 12.8mm x 2.8mm \/ 0.6\" x 0.5\" x 0.1\"\u003c\/p\u003e\n\u003cp\u003eProduct Weight: 0.5g \/ 0.0oz\u003c\/p\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":1849958105098,"sku":"ADA3492","price":4.95,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/3492-00.jpg?v=1520871399","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/adafruit-pdm-mems-microphone-breakout","provider":"Pimoroni Ltd","version":"1.0","type":"link"}