- About
- Brief information about Pmod MIC3
- Interface Description
- Simulation
- Tests
- Status Information
- Licence
Simple interface for the Digilent Pmod MIC3. This interface uses simplified version of my spi master module.
The Digilent Pmod MIC3 is microphone module with a digital interface. It contains a Knowles Acoustics SPA2410LR5H-B MEMs microphone and Texas Instrument ADCS7476 12-bit ADC. Module communicates with the host board via SPI protocol.
This interface can be used to gather data from Pmod MIC3 (or anything else that use ADCS7476) easily.
| Port | Type | Width | Description |
|---|---|---|---|
clk |
I | 1 | System Clock |
rst |
I | 1 | System Reset |
ext_spi_clk |
I | 1 | SPI clock source |
SCLK |
O | 1 | SPI Clock |
CS |
O | 1 | SPI Chip (Slave) select |
MISO |
I | 1 | SPI Master In Slave Out |
read |
I | 1 | Initiate a new read, keep high for continuous reading |
audio |
O | 12 | Most recent read data |
new_data |
O | 1 | Pulse to indicate new data is ready |
I: Input O: Output
Maximum frequency for ext_spi_clk is 20 MHz. In continuous reading mode, a new data is avaible every 1,28µs (781,25 kS/s) with 12,5 MHz ext_spi_clk. Later, recording with certain bitrates will be implemented (#8).
On Artix-7:
- Slice LUTs: 9 (as Logic)
- Slice Registers: 33 (as Flip Flop)
Module simulated in sim.v. MISO signal inverted every 70ns to obtain different readings.
Module is tested on Digilent Basys 3 with test_board.v. A very simple test module is implemented. Audio output of the interface connected to LEDs. Right button is used to get a single reading. Right most switch is used to enable continuous read mode. Pmod MIC3 is connected to upper part of Pmod port B (JB1-4).
Second test utilizes pmod DA2 to output read audio data from pmod MIC3. testBoard_dacOut.v and Basys3_da_test.xdc are used in second test. Analog output monitored via OpenScope MZ. Sinusoidal and triangular tones of different frequencies are applied and observed.
Last simulation: 12 December 2020, with Vivado Simulator.
Last test: 27 May 2021, on Digilent Basys 3.
CERN Open Hardware Licence Version 2 - Weakly Reciprocal