Build an App That Makes Phone Calls from Raspberry Pi

This project was contributed by Andy Fundinger, a professional Python developer and trainer. Andy built this integration as a way to teach his students how to make calls to their mothers on Mother’s Day, using Plivo and a keypad attached to a Raspberry Pi.

Raspberry Pi is a single-board computer that comes with

A Linux-based operating system
700 MHz ARM11 CPU
256MB (or 512MB) RAM
SD card storage
2 USB ports
Composite and HDMI video out
Stereo audio out
8 GPIO pins
Wired Ethernet

Build a Raspberry Pi call button

1. RasPi Circuit Diagram and inputs flow via GPIO

I hooked up a four-button keypad to four of the Raspberry Pi GPIO pins as inputs, then run a continuous loop to check whether the buttons have been pushed. Circuit diagram #1

Circuit diagram #2

2. Call flow via Plivo Voice API

Plivo normally expects that you’ll be using it for a web app, so I had to fake that somewhat. Rather than building a full web app, I had each student create a single page that had at least the minimum viable XML to dial a specified number in response to the call being answered. We also played with having a little more in that XML file. But basically we told Plivo that it was a web service and Plivo was OK with that.

params = {
'from': "14245550100",
'to': '12015550164',
'answer_url':"https://example.com/static/call_mom/answerThenCallMom.xml",
'answer_method': "GET"
}
p.make_call(params)

Then you execute a script that makes an HTTP GET request for “answerThenCallMom.xml”, which could be as simple as:

<Response>
    <Dial>
        <Number>14245550100</Number>
    </Dial>
</Response>

Get the code for my Raspberry Pi project on GitHub. Contributed by Andy Fundinger

Getting Started

Concepts

API Reference

XML Reference

SDKs

Troubleshooting

Voice Tutorials

Migration Guides

Build an App That Makes Phone Calls from Raspberry Pi

Build a Raspberry Pi call button

1. RasPi Circuit Diagram and inputs flow via GPIO

2. Call flow via Plivo Voice API

​Build a Raspberry Pi call button

​1. RasPi Circuit Diagram and inputs flow via GPIO

​2. Call flow via Plivo Voice API

Build a Raspberry Pi call button

1. RasPi Circuit Diagram and inputs flow via GPIO

2. Call flow via Plivo Voice API