How to Build a DIY Alexa Smart Speaker for Under $20

Building your own DIY Alexa smart speaker is a fun and inexpensive way to bring voice assistant technology into your home. With just a few affordable components, you can make an Alexa device that rivals store-bought models in functionality.

What You'll Need

To build your own Alexa smart speaker, you'll need the following components:

• Raspberry Pi 3 Model B+ - The Raspberry Pi serves as the brain of your DIY Alexa device. The 3 B+ model is fast and responsive. Cost: Around $35

• MicroSD card - You'll need a microSD card with at least 8 GB of storage for the Raspberry Pi OS and Alexa software. Cost: Around $5

• USB power supply - Any USB power adapter that provides at least 2.5A power will work. This powers the Raspberry Pi. Cost: Around $5-10

• Speaker - You can use any speaker with a 3.5mm audio jack input. Small computer speakers or portable Bluetooth speakers work well. Cost: Around $5-15

• Auxiliary cable - This 3.5mm male-to-male cable connects your speaker to the audio output on the Raspberry Pi. Cost: Around $5

• Microphone - The Amazon Alexa Voice Kit comes with a microphone board, but you can also use a USB microphone. Cost: Around $5-20

• Housing - Any household item like a plastic food container or cardboard box will work to house your DIY Alexa. Cost: Free up to $5

In total, you can build your own Alexa device for around $15 to $20, excluding the housing.

Set Up the Raspberry Pi

The first step is to set up your Raspberry Pi with the operating system:

• Install the Raspberry Pi OS on your microSD card. Use the Raspberry Pi Imager tool for this.

• Insert the microSD card into your Raspberry Pi and connect it to your monitor, keyboard, mouse, and power supply.

• Open the terminal on your Pi and run sudo raspi-config. Under Interfacing Options, enable the SSH and SPI interfaces.

• Reboot your Pi for the changes to take effect. You can now access your Pi through SSH instead of connecting it to a monitor.

Install the Alexa Software

Next, you'll need to install the Alexa Voice Service software on your Raspberry Pi:

• Register for an Amazon developer account to gain access to the Alexa Voice Service.

• Install the Alexa sample app from GitHub on your Pi:

git clone https://github.com/alexa/alexa-avs-sample-app.git
cd alexa-avs-sample-app

• Follow the instructions to generate your security credentials, configure the sample app, and register your device.

• Install any missing dependencies on your Pi like Python packages and Alsa tools.

• Run the authorized Alexa sample app. You now have a command line Alexa interface!

Assemble the Hardware

With the software installed, you can now assemble your DIY Alexa smart speaker:

• House your Raspberry Pi, speaker, and microphone in your chosen enclosure.

• Connect your speaker to your Pi's 3.5mm audio jack using the aux cable.

• Connect your microphone according to its instructions. The Amazon Mic Kit uses the Pi's GPIO pins.

• Power your Pi from your USB power supply.

• Make sure your Pi has WiFi access to connect to Alexa.

Once assembled, you now have your own Alexa smart speaker for under $20! Try asking it questions, setting timers, controlling smart home devices, playing music, and more.

Customize Your Alexa Device

Here are some ways to further enhance your budget Alexa:

• Improve audio quality - Upgrade to higher quality powered speakers or connect it to another speaker system.

• Add LED lights - Use GPIO pins to connect LED strips that light up when Alexa activates.

• Use a dedicated mic - Add a USB microphone with noise cancellation for better voice pickup.

• Make it portable - Install a battery pack to make your Alexa wireless.

• Add buttons - Connect physical buttons to mute Alexa or activate specific skills.

• Create your own skills - Use Alexa Skills Kit to develop custom skills for your DIY assistant.

The options are endless when you build your own Alexa device! With just a few affordable components, you can bring advanced voice control into any space on a budget.