Mocking Bird Telephone Exchange Master Controller

Features:

• Runs on a STM32F767ZI Nucleo board
• IDE: STM32 Cube IDE MX Development environment using Eclipse. (Needed for DMA support)
• FreeRTOS real time operating system using the CMSIS V2 interface.
• Supports 2 channels of Multi-Frequency (MF) decoding using the Goertzel algorithm using an ADC input. (70 mS min tone on and off times)
• Communicates with Subscriber line and E&M trunk cards designed by me. (More information forthcoming on them).
• Interfaces with 2 Zarlink MT88L70 DTMF decoders
• Tone Plant
  • Call progress tones
  • DTMF and MF tone generation
  • Audio samples support one-shot sequences and loops. Can be used to send nostalgic network sounds.
  • 4 channels.
  • Uses 2 TI PCM5102A DAC's to accomplish this.
• Calls are connected in analog form through 2 8X16 Zarlink crosspoint switches
• Retreives the audio samples from an SD Card hooked up to a SPI BUS.
• Supports up to 8 subscriber lines using 4 dual line cards.
• Supports up to 3 E&M trunk cards.

Project website on hackaday.io: https://hackaday.io/project/196044-mockingbird-telephone-exchange

Demo of the project on youtube: https://www.youtube.com/watch?v=1S4Ybc_A4XE