sabatesduran / rpi-touching-experience

Touching experience with a Raspberry Pi

Touching experience with a Raspberry Pi

TODO

• Add alert when not connected to the internet or an error from the fetch call
• Fix MPR121 sensitivity

Hardware

• Raspberry Pi (2, 3, Zero or Zero W)
• MPR121 Capacitive Touch Sensor
• USB Sound Card
• Speaker with AUX 3.5
• AUX 3.5 to AUX 3.5 cable

We were triyng to create little React app that uses Chrome's Speech Synthesis API to speak after a keypress event generated by a MakeyMakey but we have two problems with this:

• Doesn't work without Internet.
• The API doesn't work with Chromium (default browser for Raspbian, Raspberry Pi OS).

Our solution

We use the Google Cloud Text-to-Speech API to generate .mp3 for each key event so we can use it offline.

Install

In this example I'm using a Raspberry Pi Zero W V1.1 with Raspbian Stretch Lite.

• Install packages

sudo apt install git mgp123 build-essential checkinstall python-pip python-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsdl1.2-dev libsmpeg-dev python-numpy subversion libportmidi-dev ffmpeg libswscale-dev libavfor  mat-dev libavcodec-dev libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev libudev-dev python-smbus i2c-tools

or (havent't try this one yet)

sudo apt-get install python-pygame

• Enable i2c (Nedeed to work with MPR121)

  1. $ sudo raspi-config
  2. Interfacing Options
  3. I2C
  4. Select Yes

• Install Python 3.6 with the following gist.

  • If you can't install pip3.6 packages check this StackOverflow answer.

• Create credentials for the Google Text-to-Speech API here (You will need to add a billing account).

• Add variable to .bashrc

echo "export GOOGLE_APPLICATION_CREDENTIALS=\"/home/pi/rpi-touching-experience/credentials.json\"" >> ~/.bashrc && souce ~/.bashrc

• Install dependencies (grab popcorn and open Netflix this is going to take a while)

pip3.6 install -r requirements.txt --user

• Generate audio (check that you have Internet if you see that it's hanging in there)

python3 synthesize_text.py

• Install the USB audio card following this tutorial.

• Execute program

python3 run.py