Release Notes for PDM audio software decoding Library

Copyright 2011 STMicroelectronics

 

Contents

  1. Update History
  2. License

Update History

The PDM audio software decoding Library is an optimized software implementation for PDM signal decoding and audio signal reconstruction when connecting an ST MP45DT02 MEMS microphone with an STM32 microcontroller. It can directly take the
Pulse Density Modulated (PDM) data output from the microphone and convert it to 16-bit pulse-code modulation (PCM) format.

This Library includes one header file pdm_filter.h and binary/object codes for the following platforms:
  • libPDMFilter_IAR.a: for IAR compiler
  • libPDMFilter_Keil.lib: for ARM compiler
  • libPDMFilter_GCC.a: for GNU compiler
For more information about this Library, please refer to the document "AN3998 PDM audio software decoding on STM32 microcontrollers" available for download from STMicroelectronics website at www.st.com.

V1.1.1 / 30-December-2011

Main Changes

  • PDM Library moved from Utilities\STM32F4-Discovery to Utilities\STM32_Audio\Addons\PDM folder
  • Add new license agreement "MCD-ST Image SW License Agreement V2.pdf"

V1.1.0 / 28-October-2011

Main Changes

  • Add PDM audio software decoding Library drivers, used to decode and reconstruct the audio signal produced by MP45DT02 MEMS microphone from STMicroelectronics. For more details about this Library, please refer to document "PDM audio software decoding on STM32 microcontrollers (AN3998)".
  • stm32f4_discovery_audio_codec.c/.h: update to use DMA instead of Interrupt in I2S communication with the external codec.

V1.0.0 / 19-September-2011

Main Changes

  • First official version of the STM32F4-Discovery Board Drivers

License

The use of this Firmware is governed by the terms and conditions of the License Agreement “MCD-ST Image SW License Agreement V2.pdf” available in the root of this folder


For complete documentation on STM32 Microcontrollers visit www.st.com/STM32