#badass Woman Project Entry - Vidya Mohanan

Your Name: Vidya Mohanan

Where you live: Kerala, India

Did you attend university? Saintgits College of Engineering, MCA

Current Job: Software developer

What are your favorite electronics projects from element14 presents or youtube (they can be your projects or someone else's) - please provide links:

I like to watch, understand, and try projects based on robotics, embedded systems, and IoT.

One of the recent project from element14 presents which caught my attention is: Episode 438: Smartphone Controlled DIY Rover Using Websockets

Tell us about your project:

Motivation:

First of all. I would like to quote my audition tape here: Audition Tape for #badass Women Makers and Engineers Contest

After graduating and taking up a job, It has been a long time since I did an electronics-based project. So upon knowing about this awesome contest, I immediately made up my mind to get back into the world of electronics enthusiasts. We did a project based on Arduino Nano during our graduation period. It was a simple gesture controlled robot that will move a robot platform based on the hand and head gesture inputs from the user. The whole idea was to implement it wirelessly so that it can be controlled without the hassle of disturbing and messy wires. Even though we completed the basic project requirements, due to time and resource constraints, we were not able to succeed in realizing the wireless transmission part which we all looked forward to. This is still lurking in my mind which gave me the motivation to redesign the whole project from scratch and complete the whole project wirelessly without complex circuitry or hassle. This is developed as a simple lifehack which anyone with a basic understanding of hardware and software interfacing would be able to achieve. This lifehack and its upgrades can be implemented for a lot of applications such as industrial machine manipulation, teleoperated robots, bomb disposal units, precision robotics, etc. This project is just the tip of an iceberg to open a world with a lot of possibilities.

Introduction & Brief Overview:

The project is titled "A simple Gesture Controlled Robot" and it uses readily available day to day hobby utilities such as an RC toy car, a smartphone, a Raspberry Pi Zero, a MotorHAT, and a battery power source.

Let me give a simple graphic to understand the basic layout of the whole system.

The main parts of this system are the Robot and the Smartphone. There is a 2-way wireless communication between the robot and the smartphone.

The Robot boasts the following features:

Remote video streaming server
MQTT based message pipeline
MQTT broker hosting
DC Motor interfacing

The Smartphone contributes to the following:

Onboard sensor access for gesture recognition
Remote video streaming
MQTT based message pipeline

Your Project video:

Top Comments

Parents

cstanton over 5 years ago

Wow, so many people are using MQTT! I didn't think it would respond fast enough for a robot control, what's the latency like?
- Cancel
- Vote Up +3 Vote Down
- Sign in to reply
- More
- Cancel
vidyamohanan over 5 years ago in reply to cstanton

Hi, cstanton Thanks for going through my project. Here, MQTT was much easy and reliable than other protocols that I tested before finalizing this. Since my broker was set up locally, the latency was very very low. When I tried with a cloud broker, the latency seemed ok too but was afraid it might break in between due to the bad network in my area. Before using MQTT, I tried UDP packets. But that was unreliable even in a local network.

I believe the choice of communication protocol also depends on the application and amount of reliability that is required in that application. It was one of the choices as the data transmitted in my case is not of a higher magnitude. In case I am able to get a secure cloud MQTT broker, I intent to upscale the project so that it can be reused for a wider range of applications, and not limited to the current one.

In terms of latency, a challenge that I faced was in the custom android application that I developed. It sequentially manages the live webstream, MQTT connection, and accelerometer checks. This has caused the application to hang a couple of times when the control is shifted to gesture control that uses the onboard accelerometer to detect the user gestures.
- Cancel
- Vote Up +2 Vote Down
- Sign in to reply
- More
- Cancel
crisdeodates over 5 years ago in reply to vidyamohanan

Awesome project Vidya. This is indeed one of the best projects that I would be interested in.
If you are using MqttAndroidClient, your callbacks might be running on the main thread. Maybe you can try with MqttAsyncClient instead to call them in a background thread?
- Cancel
- Vote Up +2 Vote Down
- Sign in to reply
- More
- Cancel
cstanton over 5 years ago in reply to vidyamohanan

So're we talking 5-10ms as opposed to 1-3 seconds for low? Thanks for the reply.
- Cancel
- Vote Up +2 Vote Down
- Sign in to reply
- More
- Cancel
vidyamohanan over 5 years ago in reply to cstanton

Yes. Though I did not extensively check the latency using any program, other than pinging the raspberry pi which hosted the broker within my local network. So, from my experience, unless we use a cloud broker, we would be fine
- Cancel
- Vote Up +1 Vote Down
- Sign in to reply
- More
- Cancel
vidyamohanan over 5 years ago in reply to crisdeodates

crisdeodates... Thank you so much
Yes I used MqttAndroidClient. I will try using the MqttAsyncClient for the call. Thanks for the tip
- Cancel
- Vote Up +2 Vote Down
- Sign in to reply
- More
- Cancel

Comment

vidyamohanan over 5 years ago in reply to crisdeodates

crisdeodates... Thank you so much
Yes I used MqttAndroidClient. I will try using the MqttAsyncClient for the call. Thanks for the tip
- Cancel
- Vote Up +2 Vote Down
- Sign in to reply
- More
- Cancel

Children

No Data