Microphone problem

General
1

I am thinking of making a telepresence/security robot with a camera, microphone and speakers using “robot hat v4” but there is no built-in microphone on the card. So I couldn’t find a solution for the microphone. There is not much space for a microphone on the chassis of the robot I will make. So I want to use a very small microphone if possible.

I bought one of those crappy USB mini microphones from Aliexpress but it records the sound very, very low. I guess all these mini microphones are the same, right? Is there another alternative?

The microphone I bought seems to be USB 1.1, not USB 2.0.

/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 3, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 1: Dev 5, If 0, Class=Vendor Specific Class, Driver=lan78xx, 480M
|__ Port 3: Dev 4, If 0, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 3: Dev 4, If 1, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 3: Dev 4, If 2, Class=Human Interface Device, Driver=usbhid, 12M

The value that should be 480M appears as 12M.

Another attempt was with the i2s microphone but I was not successful. I connected the inmp441 mems microphone to the i2s line used by the “robot hat” and changed the overlay to googlevoicehat-soundcard but I could not get sound from the microphone. I want to be able to use the microphone and the speaker at the same time. If you can help me with anything I can do, I would be very grateful.

2

I’m unable to verify the specifications of your INMP441 MEMS microphone or confirm whether the device and its circuit connections are functioning properly. However, since you have a USB microphone available, you can certainly use that instead.

Regarding the low volume recording issue, you can amplify the audio through software processing. Here are two approaches:

Using SoX command-line tool:
sox input.wav output_10.wav gain 10
Python programming solution:
You can implement audio amplification using our Python utility:

Required installations:
sudo apt install sox
sudo pip3 install -U sox --break-system-packages

3

I purchased 2 different mini usb microphones for my rpi4.

Neither was particularly sensitive to sounds.

I had to increase the amplification on both to maximum using alsamixer.

One of the microphones also had AGC, which made the default sensitivity always too low. I had to disable the AGC, again via alsamixer.

4

Hi! I tried the in-box mic and had the same issue. I connected my blue yeti mic via usb to the pidog and that works good. Too good, sometimes it picks up audio I didn’t say, so I started muting the mic unless I wanted to speak to pidog.
I can’t remember how I switched from one mic to the other in ssh (I run pidog off my macbook using command terminal), but if you use VNC viewer you can remote access a desktop environment on a laptop. From there, just click on sound and select the usb mic. :slight_smile:

5

Correct. In the Bookworm system, click the ‘Sound’ icon in the top-right corner of the desktop and select the corresponding microphone device from the options.

6

After some effort I managed to connect and power up the i2s microphone. I soldered the i2s microphone to raspberry pins 12, 35 and 38 on the robot hat. In config.txt I only enabled the googlevoicehat-soundcard overlay.

At first there was still very little sound. For this I created the asoundrc configuration found in an adafruit article Raspberry Pi Wiring & Test | Adafruit I2S MEMS Microphone Breakout | Adafruit Learning System.

And voila! The i2s microphone and speaker work perfectly!

7

Hope you have fun.Any further help,please feel free to contact.