Archive for June, 2014


Thursday, June 19th, 2014

Pablo is a physical chatbot. An open source social robot.

Pablo got his name from (PyAIML Arduino Bluetooth Low-Energy Object) or something like that.

1. A Python program running on a host computer accepts input from a web form.
2. Input is interpreted using Artificial Intelligence Markup Language (AIML)
3. Response is sent via Bluetooth and spoken by Pablo.

Pablo is open source software and hardware. Code can be found on GitHub

He can be found on Twitter here

Using the basic PyAIML example plus a simple webpy form we are able to talk to PABLO. I still need to get the text-to-speech Javascript API working. I was using the speech-to-text input feature in Chrome (x-webkit-speech) but it has since been deprecated.
AIML responses are constructed from a set of reduced answers to planned questions. eg. “What’s your name?” “Who are you?” “What are you called?” = PABLO.

NOTE: The USB cable in the eye is a temporary 5v power source only.
Not quite Natural Language Processing but with random responses and recollection it can make for a convincing conversations.

On the physical side of things, PABLO is made up of:
Pablo in pieces

(Clockwise from top right)
Arduino Duemilanove microcontroller (Or any compatible)
Adafruit BlueFruit EZ-Link Bluetooth Shield
Emic2 text-to-speech Module
1000 mAh Lipo battery
2 Adafruit NeoPixel rings (I’m using one 16 and one 12 pixel)
Adafruit 3v Trinket
Adafruit 4-channel I2C-safe Bi-directional Logic Level Converter
2 Hobby servo motors with Pan-tilt brackets
Cardboard head with wire-spool LED diffusing eyes
8 Ohm speaker

An Arduino with the Adafruit EZ-Link Bluetooth Shield receives the response from the host computer. The response is interpreted then commands issued to eyes, servos, and speech module. I used the proto area of the shield to connect headers to which I can temporarily plug in the text-to-speech module, two servo motors, and the level converter connection to eyes.

The eyes are controlled by a small microcontroller from Adafruit called the Trinket and is powered by the lipo battery. They are self supported and can easily be repurposed for other projects. I used a 16 pixel ring and a 12 pixel ring which made some of the eye functions a little specific to this build. The logic level converter is used to receive commands over I2C from the 5v Arduino microcontroller using the Tinywire library.


Everything is currently crammed into a cardboard box with a speaker pointed down into the mouth. A talking function randomly moves the jaw servo while Pablo is talking, opening and closing the mouth. This combined with the advanced settings of the Emic2 voice module make for endless hilarity. A second servo twists the head briefly, as one might picture a confused dog, when an answer is not known. The datasheet from Parallax(PDF) shows you how to change the basic settings and take advantage of the more powerful DECTalk processor.

Lots of things to build on, still tons to do, least of which is his “personality”.

I plan to document more of the details and code as I go because today I’m hoping Pablo can help me win a trip to space! If not, he’s about the size of a CubeSat and I’ll send him into space.

UPDATE: Pablo was honoured to make an appearance on Adafruit’s July 23rd Show and Tell!