User manual

Basys MX3™ Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 41 of 56
Figure 18.2. Microphone frequency response.
The output of the microphone module is an analog signal A_MIC, connected to an analog input pin of PIC32. This
analog pin must be sampled using the PIC32’s ADC functionality to get a digital value. The PIC32 provides 10-bit
data ADC sampling. Read more on the PIC32’s ADC functionality in the Analog-To-Digital Converter (ADC) section of
the PIC32 documentation.
The microphone on the Basys MX3 also features adjustable gain that is controlled using a thumbwheel
potentiometer labeled MIC VOLUME. This dial directly controls the gain of the A_MIC signal going into the PIC32.
18.1 Connectivity
Table 18.1 below shows the details about the A_MIC signal connecting the microphone module to the PIC32.
Name
PIC32 pin
SPA2410LR5H-B pin
A_MIC
AN4/C1INB/RB4
OUT
Table 18.1. Microphone connectivity.
The A_MIC pin will be used as analog input pin:
 The corresponding TRIS bit must be set to 1:
TRISBbits.TRISB4 = 1;
 The corresponding ANSEL bit should be set to 1:
ANSELBbits.ANSB4 = 1;
18.2 Functionality
The microphone usage is described through library functions in the MIC and ADC libraries of the Basys MX3 library
pack. Implementation features include: