PDM MEMS 마이크로폰 모듈
(Adafruit PDM Microphone Breakout with JST SH Connector)
개요
- 본 제품은 PDM MEMS 마이크로폰 모듈입니다.
- PDM은 제3의 마이크로폰으로 I2S나 아날로그를 사용하지 않고 PDM(pulse density modulation) 출력을 사용합니다.
- 디지털이지만 PWM 신호도 아니고 I2S 신호도 아닙니다.
- 이 제품을 사용하시려면 MCU가 PDM 인터페이스를 지원하는지 확인하셔야 합니다.
- PDM은 1비트 PWM과 유사합니다. 마이크를 1Mhz-3Mhz 클럭 레이트로 클럭시키고, 데이터 라인상에서 클럭과 싱크된 스퀘어 웨이브 출력을 얻게 됩니다. 데이터라인은 0이나 1로직 출력을 내고 이는 결과적으로 아날로그 전압 출력 값을 가지게 됩니다.
특징
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Wiring, schematics, example code, datasheets, Fritzing and more in the product tutorial!
- Voltage Range: 1.8-3.3V
- Clock rate: 1 - 3.25 MHz
- Current draw: 0.6mA
- SNR: 61 dB
- Sensitivity: ~-26 dBFS
Product Dimensions: 14.0mm x 14.0mm x 4.5mm / 0.6" x 0.6" x 0.2"
Product Weight: 0.7g / 0.0oz
문서
- Adafruit PDM Microphone Breakout
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There's a few ways to manage these mics:
- Your 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 (The nRF52840 is like this and it is ideal!)
- Your 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)
- Your chip does not come with a hardware peripheral but you're pretty clever and come up with a way to make it work using SPI (See this example for the ATtiny85)
- You generate the high speed clock, then add an analog filter on the data line, and read the analog value (A hack, but works!)
Either 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!
Each order comes with one fully assembled and tested microphone. This version of the mic has a 4-JST SH connector with 3V, GND, DAT, CLK connections that can be used with one of our JST-SH cables to make a flexible mic arrangement. If you want a version with breakout headers, we have a version here. An on-board solder jumper lets you change the mic from Left to Right channel
Check out our full guide for wiring details, schematics, example code, datasheet and more!