We’ve all seen the old movie scene where the executive calls his assistant on the intercom for some task or other. [Jan] may not be an executive, and he may not have an assistant. He does have Raspberri, his voice controlled personal digital assistant. Raspberri started life as a vintage Televox intercom box. [Jan] found it at a second-hand store, and snapped it up in hopes of using it in a future project. That project eventually happened when [Jan] got a Raspberry Pi and learned how to use it. He decided to build the Televox and Pi together, creating his own electronic assistant.
[Jan] started by adding a cheap USB sound card and WiFi module to his Pi. He also added a small 3 Watt audio amp board. The Televox used a single speaker as both audio input and output. [Jan] didn’t want to make any modifications to the case, so he kept this arrangement. Using a single speaker would mean dead shorting the audio amplifier and the sound card’s microphone input. To avoid this, [Jan] added a DPDT relay controlled by the original push-to-talk button on the Televox. The relay switches between the microphone input and the audio output on the USB sound card. Everything fit nicely inside the Televox case.
With the hardware complete [Jan] turned his attention to software. He went with PiAUISuite for voice input. Voice output is handled by a simple shell script which uses google voice to convert text to speech. For intermediate processing, such as scraping a weather website for data, [Jan] created custom python scripts. The end result is pretty darn good. There is a bit of lag between saying the command and receiving an answer. This may be due to transferring the audio files over WiFi. However, [Jan] can always get away with saying his assistant was out getting him more coffee!