35 lines
1.5 KiB
Markdown
35 lines
1.5 KiB
Markdown
|
|
# Stream I2S Input to A2DP Bluetooth
|
|
|
|
## General Description:
|
|
We implement a A2DP source: We stream the sound input which we read in from the I2S interface to a A2DP sink. We can use any device which provides the sound data via I2S. In order to test the functionality we use the INMP441 microphone.
|
|
|
|
|
|
|
|
The INMP441 is a high-performance, low power, digital-output, omnidirectional MEMS microphone with a bottom port. The complete INMP441 solution consists of a MEMS sensor, signal conditioning, an analog-to-digital converter, anti-aliasing filters, power management, and an industry-standard 24-bit I²S interface. The I²S interface allows the INMP441 to connect directly to digital processors, such as DSPs and microcontrollers, without the need for an audio codec in the system.
|
|
|
|
## Pins
|
|
|
|
| INMP441 | ESP32
|
|
| --------| ---------------
|
|
| VDD | 3.3
|
|
| GND | GND
|
|
| SD | IN (GPIO32)
|
|
| L/R | GND
|
|
| WS | WS (GPIO15)
|
|
| SCK | BCK (GPIO14)
|
|
|
|
|
|
SCK: Serial data clock for I²S interface
|
|
WS: Select serial data words for the I²S interface
|
|
L/R: Left / right channel selection
|
|
When set to low, the microphone emits signals on one channel of the I²S frame.
|
|
When the high level is set, the microphone will send signals on the other channel.
|
|
ExSD: Serial data output of the I²S interface
|
|
VCC: input power 1.8V to 3.3V
|
|
GND: Power groundHigh PSR: -75 dBFS.
|
|
|
|
### Dependencies
|
|
|
|
- https://github.com/pschatzmann/ESP32-A2DP.git
|
|
|