Introduction: Make a Voice Controlled Robot

Picture of Make a Voice Controlled Robot
(requested for contest, 18+ age category)

This tutorial will show how to build a simple voice controlled robot that's easy enough for beginners to make in just a few hours. I show how it can be done in two languages, both English and Thai.

The cost of the entire project is about ~$224, which factors in quality components and parts.

There will be three parts to this tutorial. This part will show you how to assemble the robot mechanically, the next part will show you how to program your microcontroller, and the last part will be how to configure voice recognition.

Watch the video for step-by-step instructions, and see the result at the end. If you like it, please boost my ego and rate this Instructable =)

Step 1: Parts Needed

Picture of Parts Needed

You can find all the parts you need for your robot using this handy-dandy robot parts list .

(2) servos - I used HS-311 for ~$8.99 each

(2) servo mounts $1.95

(2) wheels - I custom made these using a CNC (although a laser cutter would be better), but you can buy some for ~$3 each

(1) 6V NiMH battery - about ~$22 for a quality battery

(1) small piece of plastic (scrap)

(16) 4-40 screws ~$2

(1) Axon II microcontroller  $118

(1) VRbot Voice Recognition Module $57.95

Step 2: Installing Software

Now that your robot is assembled, we will now program the robot.

If you have never used the Axon before, the getting started tutorial will get you up and running quickly:

The fully commented source code to this project can be downloaded here:

You will need AVR Studio to upload the .hex file to your Axon - no programming required. But feel free to modify it should you want to do more.

This tutorial video will now show you how to customize the software of your robot using WebbotLib Project Designer .

The robot in the video you saw uses this following code:

It includes a WebbotLib Project Designer file

Step 3: Configure VRbot

Picture of Configure VRbot
The last step is to program in your voice commands using VRbot. The easiest way to do this is with a TTL serial to USB adapter. I used the Sparkfun FTDI board . Make sure you power your VRbot using the 5V USB output, not the 3.3V output or it won't work. The VRbot manual has more specific details if you get stuck.

After connecting the VRbot module to your computer, follow this manufacturers video tutorial on how to use their GUI software :

The specific list of commands programmed into the VRbot are as follows, although many were not used in this demo:

Group 1:

Group 2:

Step 4: Upgrade Your Robot

Picture of Upgrade Your Robot
Now that you have the basics done, start adding more servos and other voice commands to slowly build up your butler robot.

This of course is beyond the scope of this Instructable so I won't go into further detail, however I want to show what possibilities there are.

This video demonstrates higher level commands for your robot. If you'd like to get designs and source code for this robot, as well as find out more, I've documented it all here:

Step 5: About the Axon II Microcontroller (shameless Plug)

(FYI - I'm the creator of the Axon, so I'm biased)

Why use the Axon II instead of the Arduino?

The Axon requires only one 6V battery to run everything, while the Arduino requires two batteries - a 6V for servos and a 7.2V battery for the microcontroller. The Axon is plug-n-play while the Arduino requires additional costly shields and rats-nest protoboards. These are hidden costs of the Arduino.

The Axon is just as easy if not easier to use than an Arduino, with simple drag-n-drop programming using WebbotLib Project Designer . The Axon is ~2x more expensive, but has ~3x more features.

Here are a few videos on how simple it is:



anilj28 (author)2017-09-09

can i use this Microphone Voice Sound Sensor Module For Arduino instead of vrbot module?

12501583 (author)2017-02-27

Question, can we make it with four smaller wheels

Micah200 (author)2016-09-19

cool I will make it

CreativeBlossom (author)2016-08-11

SO COOL!!!!! :)

AtrayanM (author)2016-05-24

Can i use a arduino uno r3 instead of an axon 2 microcontroller ... cz its cheaper ....

Patricknks (author)2016-01-30

Can i make thos project with arduino, what arduino series should i use, and how to make it. Thanks

OliverO4 (author)2015-12-12

I am making a robot, so Im using more than 2(about 9) servos, should I get a different battery or is that battery still fine

IanM102 (author)OliverO42015-12-22

If all servos were running they would be slow or not work at all. Size of battery shouldn't matter if you were only using 1 or 2.

OliverO4 (author)IanM1022015-12-22

so basically get a different battery, what do you suggest I should get for 9 servo humanoid robot?

IanM102 (author)OliverO42015-12-24

I would choose Lead-Acid for lifetime, but lithium-ion should work best for size, amp hour, and the least maintenance.

OliverO4 (author)IanM1022015-12-24

did a couple of research yesterday and I'm completely new to robotics and I heard lithium ion batteries are very dangerous and can explode, I was thinking of getting nimh batteries but found out those can explode too, the robot might use 9 servos but it still won't be that big so won't lead acid be to heavy?

IanM102 (author)OliverO42015-12-25

For lead-acid just don't use car batteries, they do sell them down to a size of D-batteries, so you would want to connect them in a series for voltage and parallel for amp hour.

OliverO4 (author)IanM1022015-12-25

okay, thank you, and how safe are lead acid batteries, also I don't understand that second part about connecting them in a series for voltage and parallel for amp hour

IanM102 (author)OliverO42015-12-25

They are mostly safe, I recommend "no maintenance" specified battery, also don't overcharge or over-discharge them, aka get a charger for them. Series is positive to negative and negative to positive, and continued. Parallel is positive to positive and negative to negative.

OliverO4 (author)IanM1022015-12-25

thx so much, so if I get an actually charger for them its not possible to overcharge/over discharge? it'll automatically stop charging when its full?

IanM102 (author)OliverO42015-12-26

Yes if it measures the batteries charge and adjusts its output, it can prevent overcharge, but not over discharging. I recommend recharging when the servos become slow, and always keeping it in the charger when not using it.

OliverO4 (author)IanM1022015-12-26

ok im guessing discharging is when you use the zapper to zap electricity into the battery, I won't be discharging, but I will be using the battery for a robot so I'll be using it all the time, is that bad? I want to make a robot that will never get turned off, just goes to sleep every night/charges

IanM102 (author)OliverO42015-12-27

Over-discharging is when you use to much power for one cycle. It is not bad if you're using it all the time for lead-acid.

saratchendra (author)2015-12-14

can i get the block diagram

how the voice module identify the voice and process the voice

if possible mail me

sentra6979 (author)2015-09-23

What size wheels did you use?

OliverO4 (author)sentra69792015-12-12

size doesnt matter

kevin.c.gabriele (author)2014-12-06

Is there a software or website that i can make or have made a program to run through my pc via bluetooth to my robot costume so i can entertain a crowd without having to do the talking? Thanks for any help

hi i want to create a small watch where u can speak to it and it will display the words, how can do that using your idea so that it does not require a computer to work

Theeba (author)2014-08-21

Hi, I'm currently building voice control robot using Easy VR Commander and arduino, I have made the my robot to listen my commands and execute the commands by connecting it to the computer.But as I have seen your video your commands are listened and executed without connecting to the computer. I'm very keen on knowing how did you do that ? Would you let me know how to do that, much appreciated.

KCAscienceclub (author)2013-10-21

Hi I had a couple of questions. Our club is building your design to get started and are stuck on what device to click on in the project designer, for the VRbot audio device. In Audio menu there are only three options listed. SOMO 14D, Text to speech, or Tone player.
Also to connect audio device to computer to program, can we simply make a cord that goes between the usb port and the audio device? If we use the Axon 2 i am a little lost on how to download the audio software through the project designer. KCA science club

Try this:

lnani (author)2013-06-03

the same voice controlling system i want to use to my car for start/stop etc. could you help me in fixing them and tell me the parts i need and how to make it run?

bhavyamadan (author)2013-04-02

hi there i was just wondering if your code would work with the arduino and if yes how would i need to connect wires to my arduino like the servos and all

zdavid8376001 (author)2013-03-26

Can you tell me where to get all the materials?

Husham Samir (author)2012-06-19

Amazing project!!!!

mschwarz7 (author)2012-05-25

If i wanna use an Arduino insted AXON II, what board should i`le have to use? Can you give me a link?

It works with the Arduino, too.

pintu0809 (author)2012-05-29

i want to make a simple project that will work on the voice to start a engine of bike. can v use vrbot to it and how to configure it and use it to connect to a bike?

roboguy22 (author)2012-01-25

hello...ur simple robot is supercool... i am trying to make one for my project......can u solve my some doubts..
1) can i use any other microcontroller if axon is not avaliable.
2)can i use any other simple voice recoginition module...
as i am a beginner how can i program axon 11 or any other microconroller

uzma1134 (author)2012-01-12

thank you for such a wonderful tutorial.
sir, i would like to know weather we can use any other microcontroller instead of axon 2 mc with vrbot.
as this microcontroller is not available in india.
or any other way to make a voice controlled robot.
thank u

michealcollins (author)2011-09-19

This is so freakin cool. Totally gonna try and build it. Thank you for this great instructional video!

babu1423 (author)2011-07-15

where did you buy the VRbot Voice Recognition Module ??????
i loved the robot

societyofrobots (author)babu14232011-07-16

It's the very first result on google, silly =P

endr56 (author)2011-06-22

i dont get it

tinker234 (author)2011-06-11

hey could you recomend a speach requatin program and a responce like hi and hello some thing like that

It's not entirely clear what you want.

Try posting your question here, there are several experts that will probably have good advice:

(try searching the forum first)

John (admin)


shadow98 (author)2011-04-03

I love this robot. I'll be building this soon. It'll be a nice collection to all the robots i've built. Although the microcontroller and the voice recognition module cost alot!

karan13 (author)2011-03-12

is it necessary to use TTL serial,cant we directly use axn 2 for it.if yes how to use it

societyofrobots (author)karan132011-03-12

You need to link to your PC to configure it. You can use the Axon II as a TTL to USB adapter if you'd like. Code for that is in the Axon II demo files folder.

swighton (author)2011-02-17

A few things about step 5/the axon:

-The arduino does NOT require 2 batteries. You can easily power an arduino and servos off one 6V or even a regulated 5V supply (I do it all the time). Why would you think/say that you need two - that's just misleading.

-You can use an arduino to drive servos and interface with a voice recognition module as you did here without any kind of shield.

-You claim that the axon is plug and play, requiring no shields or protoboard - Tell me then, how do you drive anything that draws >20mA of current such as a standard hobby motor that is a 1 amp inductive load requiring power handling components in the form of a shield or custom external circuit?

-The axon is actually ~3.25x as much as a standard arduino, perhaps you are including shield costs, but this project requires no shields if implemented on arduino.

-What are the 3x features that the axon has over arduino? Is it not an 8 bit atmel microcontroller broken out on a dev board just like the arduino? I bet you can even use the axon drag and drop programming tool with an arduino.

-The only advantage I see is that this microcontroller has is that it has built in headers to connect servos to it (it's an advantage if that's what you are looking to do).

societyofrobots (author)swighton2011-02-17

Hi kraker89, you asked some very good questions.

> The arduino does NOT require 2 batteries.
The Arduino, unless recently changed, does not use a LDO voltage regulator. The regulator simply won't turn on when using a 6V battery, unless that battery is fully charged (meaning its closer to ~6.7V). That basically means it requires a 7.2V battery to run the on-board logic. A servo will run on 7.2V, but most batteries aren't designed to handle more than 6V. Operating at higher voltages, even on a fully charged 6V battery, will greatly reduce the lifespan of your servo. I suspect you are running your Arduino on a fully charged 6V.

> You claim that the axon is plug and play, requiring no shields or protoboard
I made no claims to having an on-board motor driver. It's 'plug-n-play' in that it doesn't require a breadboard or a special shield - ie you can simply connect directly to the Axon bus and be done with it.

> The axon is actually ~3.25x as much as a standard arduino
The Arduino has a lot of hidden costs, like you said, such as the cost of a protoboard, wiring for that protoboard, the additional battery, and shields. As the voltage regulator on the Arduino is a low efficiency type, you'll also burn through your battery faster, meaning you need a bigger battery to get the same bang for the buck. It's not a hard number as it depends on what your project requires, of course.

> What are the 3x features that the axon has over arduino?
Again, it really depends on what your project needs. The Axon has 4x as many UART ports, 4x as many PWM and interrupt ports, 4x the memory, 3x the total I/O, 2x the timers, and 2x as many ADC ports. I consider being smaller a feature, as well as the power buses, but thats more qualitative. I also consider the higher efficiency LDO regulator a feature as well. You may not consider these features, but try making a biped with 16 servos and you'll see quickly the advantage the Axon has. I honestly can't see myself making a robot with less than 4 UARTs (GPS, voice recognition, bluetooth wireless, Blackfin camera, USB, Razor IMU . . . thats 6 already).

> I bet you can even use the axon drag and drop programming tool with an arduino.
Yeap, WebbotLib supports the Arduino. But you'll find limited memory and limited timers on the ATmega168 preventing you from fully taking advantage of it. The 328 on the newer Arduinos is fine, though, as it has more memory.

swighton (author)societyofrobots2011-02-23

Dang I was totally wrong - I had no idea that the standard arduino didn't use a LDO voltage regulator (I use the pro mini). That's a pretty huge oversight on their (and my) part - I was thinking of getting one but on second thought I think not.

Your other arguments are reasonable as well. Good points. Reading my previous comment I may have been a bit over aggressive. Apologies!

societyofrobots (author)swighton2011-02-24

no probs =)

henadeera (author)2011-02-20

Its so interesting... Can I use PIC10F micro controller instead of Axon II ?
Hope pic10f is more smaller and more energy saver..Any idea?

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