How to Build a Robot to Feed Your Fish (and other things)

It’s not terrifying like those Boston Dynamic robots opening doors and doing backflips and things. In fact, it’s more along the lines of WALL-E, an adorable and helpful assistant that keeps your fish (and other things) alive and running.

Today we’re featuring a great project from Juan Miguel Jimeno, who combined a number of technologies to build an autonomous home assistant robot that can feed fish and grab a soda from the fridge, with the ability to be programmed to complete a vast amount of other things as well.

Dubbed O’nine, the robot needed to be able to move around, as well as move its arm and claw to carry out tasks. Additionally, O’nine voice-activated, able to listen and carry out voice commands. According to the maker:

Current smart home solutions require custom rigs that are devised just for a specific function. O’nine aims to bridge this gap by minimizing these hardware requirements and use robotics as an alternative.

So, how can we build a mobile robot that accepts voice commands? That’s exactly what the full tutorial on shows. In this post, we’ll give you an overview of the underlying technology and how it works. When you’re ready to build one like it, head over to the full tutorial to see the code and a full walkthrough.


Echo and Software

So, how’s it all tied together? It starts with Amazon. An Echo Dot listens for voice commands and uses Alexa Skill to analyze and detect the intent of the voice command. AWS Lambda then receives the processed request from Alexa Skill and publishes the message to PubNub.

PubNub is the glue that bridges the gap between the Amazon hardware and services, and the O’nine itself. Using the PubNub MQTT broker that O’nine is subscribed to, O’nine can then carry out the action through the ROS Robot Operating System. All this happens in a couple seconds.

There’s a deep dive on the software side of things available here.

O’nine Hardware

The tutorial offers a great deep dive into how to wire up the hardware, including the Arduino Braccio Robotic Arm, Mecanum Wheels, bod unit, and the Arduino Uno.

O’nine In-Action

In the end, O’nine is a glorious, obedient robot willing to carry out your tasks. Armed with a mobile and flexible arm unit and efficient wheels, O’nine can easily navigate around your house and do as you please. is a great resource for robotics, home automation, and other IoT use cases like O’nine. And if you’re looking for any help building the messaging layer, or are interested in getting started with device control and monitoring, feel free to reach out to us, we’re here to help!

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