Halloween Voice Changer With Raspberry Pi

Make your own voice changer for your Halloween costume

This tutorial show you how to make your own customizable voice changer for Halloween. At the end you will have a very compact voice changer with multiple voices, unless industrial commercial voice changer this one is open source so you can make your own voice.

• 1 Raspberry PI Zero (it will also work with raspberry PI 2 or 3 and 3B 3B+, but the zera is smaller and consumes less battery.
• 1 micro SD card 8Go or bigger
• 1 micro USB cable
• 1 MIC+ sound card it is perfect for the job as it has one integrated microphone, and two onboard speakers and it is the size of a Raspberry Pi ZERO (it is available on Amazon Prime)
• 1 Halloween mask, here we will choose a mask with a solid plastic front to hold the Raspberry Pi
• Play dough (modeling clay)
• Double sided tape
• Any metal wire

Skills : Basic computer use

Time: 1h

• Download archive here
• unzip it and copy the image file somewhere on your desktop (it could take a few munites)
• Burn the .img file on the SD card, on windows you can use Win32 disk imager , load the image file, select your SD card units drive (here G:) then click on Write

• Take the MIC+ sound card and separate the microphone from the main board
• Use a cutter to weaken the part shown of the picture, give at least 10 passes of the blade above the little holes, then use your finger to apply pressure, try not to push too strongly of the microphone component (metallic rectangle). Then connect the cable as shown in the picture.
• Insert the SD card burnt before
• Put MIC+ on top of the Raspberry PI Zero, and plug it to the USB charger, it will take 2minutes to boot, when ready the led will turn ON:
• Push the yellow button to switch between preset voices, the talk into the microphone, it the Mic is too close you wil have echo, so position the microphone behind the speaker.

Time to fit into your Halloween mask use Playdough this will isolate the microphone from the speaker feedback to avoid Echo, another trick is to use soldering/metal wire to position the microphone the closer from your mouth and further away from the speakers

• Maybe you want to change the sensitivity of the microphone or power of the speaker:
  
  • you can directly edit the following files on the SD:
    • type: "sudo nano /home/pi/l1"
    • The script look like that:
    • echo "************l1*************"
    • amixer set Master 98%
    • amixer set Micro 4%
    • play |rec -c 1 -d --buffer 4096 pitch -400 gain +22
    • Change the Master % for speakers volume, Micro % gain, then you can play with the soc parameters
• You can choose not to install the pre cooked image, you need to download the latest Raspian,
  • then install the MIC+ sound card,
  • then install sox: apt-get sudo install sox