Getting Started, Omnibot Hacking For Beginners

aliusa

USA

Hi Guys,

When rummaging in the attic I found my old Omnibot with the remote and the original battery pack:) The battery is dead but I popped in two double A's and the digital clock still works. I was too young to really understand what I had was more than just a toy (I was 5 when I got it).

Anyway, I want to work on a project with my daughter. She's 7 but she's taken a real liking to electronics after I got her a snap electronics kit. Can anyone suggest a good project and what basic hardware I should purchases (servos, sensors, etc.) to get started.

Thanks, Ali

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United Kingdom
#1  

I would say that everything included in the Developers Kit would be a great start for hardware required.

You wouldn't require the 2 continuous rotation servos but everything else would be used.

I haven't done the maths but you could buy what you need from this kit separately; EZ-B V4 2 Heavy Duty Servos for the arms 1 Heavy Duty Servo for the head pan HC-SR04 Sensor for object avoidance Camera

Also throw in a 2.5A Motor Controller for control of the original Omnibot drive train.

To do the conversion would be pretty simple and there are a lot of examples available in the Community Projects.

It will ultimately come down to how far you want to go with it. I started out with a Hearoid (Omnibot with a different head) and was going for a simple conversion with everything hidden, that changed...

Personally I would go for the developer kit option along with the 2.5A Motor Controller and a bunch of accessory extensions, this will give you the freedom to build a simple robot, such as Box Bot, then take that and use what you learned to build something else using the same parts.

#2  

Rich,

Thanks for the quick response. The EZ-B is comparable to an Arduino?

Thanks, Ali

United Kingdom
#4  

The EZ-B is like the Arduino may eventually become in 10 or 20 years :D

The major difference is that the EZ-B needs a host, a PC or portable android or iOS (coming soon) device to run the code and tell the EZ-B what to do. The code, script, project, stamp, whatever you want to call it or think of it like isn't sent to the EZ-B.

This makes the EZ-B very powerful since it has the computing power of your PC. This allows for very accurate controls. It also allows for very easy to make projects which don't require a whole lot of effort and can be modified on the fly with no problems.

To put it plainly, forget the Arduino, forget what you know about the Arduino, that stuff will just confuse you.

#5  

Rich,

Arduino who? :)

I shouldn't have issues when it comes to programming. The hardware engineering aspect is new to me, soldering, etc. So it should be a good learning experience. I will likely purchase the developers kit, it seems to include everything I'll need. Any good tutorials besides the DJ Shures ones I can watch and while I wait for the developer kit to be shipped?

I'm guessing Raspberry Pi would still be a weak interface?

Ali

United Kingdom
#6  

Just go through the showcase robots, there are some awesome examples in there.

As for hardware, the EZ-B and all EZ-Robot parts are made so that no soldering is actually required. It is very easy to use. Jumper cables can be used to link everything together with minimum fuss and work. And doing it that way means you can, if you want to, reuse parts from an old robot you built and put them in a new robot you are making.

#7  

I think Pi's use ARM processors so you wouldn't be able to run ARC itself on it BUT, if it had Android 4.x, i think it would run the EZMobile Android app.

I don't know a whole lot about Pi's. With the power and size of tablets and such I just haven't found a need or reason to spend the money on one. Maybe someone with some Pi experience could deny or confirm this?

I base my assumptions on my Transformer Tablet and Droid 4 Smart Phone having ARM processors.

United Kingdom
#8  

Yes the Pi runs an ARM CPU. No it can't run ARC. However, it can run python or some lightweight flavours of linux. It's possible to run the OpenBot on the Pi but you will miss out on the true power of ARC. It would be like (as DJ said about something else recently) like putting a pinto engine in a Ferrari.

#9  

Thanks Rich for the help. I'll be order the kit once it's in stock.

#10  

With the developer kit does that include the battery source to operate the omnibot (and the wheels)?

Thanks

United Kingdom
#11  

It comes with a 6 x AA battery holder which will power the EZ-B and motors but wouldn't last long.

I'd advise getting a different battery. A 2s LiPo gives 7.4v and come in a variety of capacities, I use 5000mAh personally. There is a compatible battery and charger in the EZ Robot store.

#12  

I was going purchase the kit during the sale but had a pretty bad accident that put me in the hospital. What was the sale? And will it come around again?

Thanks, Ali

#13  

Black Friday sale was 20% off of everything in the store...

United Kingdom
#14  

I would guess it'll come around again next year however with such a small profit made per item in the store there may not be any other sales in the near future.

Occasionally people will post offering their kits for sale for various reasons, MovieMaker recently sold his two as he is giving up building robots, keep an eye on the forums for others. Or enter contests etc. to win store credit that'll help towards the purchase.

#15  

Would the original battery with omnibot work with the kit? I'm about to unscrew and rip the guts out and wanted to know what I should keep.

#16  

The ezb can work with voltages from 5V ~ 17V.... If the battery is still good after so long, I would assume yes...

United Kingdom
#17  

Yes it will, Melvin originally used the original Omnibot battery (since been upgraded) so I now use the 6v SLA occasionally for testing.

Be aware, the original wiring for the Omnibot was backwards! Test your Vcc and Ground before connecting to the EZ-B.

#18  

Thanks for the heads up!

To make the eyes/head rotate did you guys cut the square corners to make it round?

Has anyone modded by sticking a mini PC inside? Actually I saw one video where some stuck a netbook with USB replacing the BT. I rather keep the BT and control it remotely.

Speaking of remote controls, which ones do you guys use?

I know a have a boat load of questions...

Thx for being patient.

#19  

ARC has built in controls to use with a wii, a playstation controller or even with the keyboard on your PC...

#20  

Any recommended Hbridges you guys suggest to use with the existing drive train?

I have a few tablets laying around... Has anyone tried to mod that into the front as a console? My only concern is the power consumption. It'll be more for "show" since my tablets are all android base.

Ali

United Kingdom
#21  

The L298n is perfect for the omnibot drive train. I've also used the TB6612FNG motor driver from Sparkfun without issue (however it is only 1A Dual Channel not 2.5A Dual Channel like the L298n).

L298n is the better one in my opinion since it has on board voltage regulator and is easier to wire up.

#22  

Mr. Ali, Solamelikem ,

 D.J. has a Very Good tutorial on how to modify the omni-bot 2000. His is one of the best on the board. Some of the others might give you a lot of headaches. I would go with that if I were you.

Good Luck!

#23  

Thanks everyone

Rich: Something like? http://www.instructables.com/id/Arduino-Modules-L298N-Dual-H-Bridge-Motor-Controll/

As far as the EZ Robot kits -- Where are they shipped from and what's the usual shipping time for US? I read the shipping terms... lot of fine print, would it be better to buy it from locally from Ebay (even though its a few dollars extra)?

Thanks, Ali

#24  

EZ Robots are manufactured and shipped from China.... Headquarters is located in Calgary, Alberta Canada... Shipping is via DHL. The actual shipping time is about 3 days, however do to current heavy volume it will be probably a week or two to process your order...

You may not find much on eBay right now because it is so new... However, try Robotshop.com (Robotshop.ca has some) to see if they currently have stock to ship....

#25  

Alberta! Great:) Another reason to justify it to the wife:) She's originally from Alberta LOL

http://www.ebay.com/itm/EZ-Robot-V4-Personal-Robotics-Developer-Kit/221558003562?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D27538%26meid%3D15fc390a1ad94e2eb7d296a71135bc50%26pid%3D100005%26prg%3D11353%26rk%3D1%26rkt%3D6%26sd%3D331394334274&rt=nc

Thanks, Ali

#27  

Bit the bullet purchased: o EZ-Robot WiFi Developers Kit o SeeedStudio L298 Dual H-Bridge Motor Driver o DFRobot Assorted Jumper Wires Premium M / F Pack of 65 o DFRobot 7.4V Lipo 2200mAh Battery (Arduino Power Jack) o 18W LiPo Battery Charger

Anything else I need to get started on my Omnibot while my wallet is still out:) ?

United Kingdom
#28  

It's knowing where to stop!

I had a budget for Melvin, I used that budget 5 times over already!

Spiral wrap is handy to have to keep wires neat, or tape...

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Protoboard, TIP122 transistors, resistors, header pins, solder, glue, filler, fibreglass, hot glue...

#29  

What does the front of Melvin look like?

#31  

For cutting the excess plastic around the head/eyes I will use a dremel but what do you suggest about smoothing out the plastic -- 200 grit sand paper?

The dome is scratched and beaten. I remember as a kid the painters dropped white paint on it too:) Any thoughts about smoothing that out?

Thanks, Ali

United Kingdom
#32  

There are reports (however I've personally never managed it) that using toothpaste can remove scratches from the dome. Or sanding with 2500 grit wet & dry.

I haven't yet smoothed any of Melvin's plastic. The dremel tends to melt it anyway so it leaves a pretty neat edge. But yes, sand it, 200 moving up to 800 or 1000 should do it depending on how you finish it (paint?). You could go mad and go up to 2500 grit, polishing compound etc. but it's probably not needed if you paint it, in fact you want a slightly rough surface anyway for paint.

#33  

It has begun!

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I will start with the drivetrain. This is the H-Bridge I bought. Anyone have a tutorial for this one?

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#34  

I'm back and working on the OmniBot hack.

I liked how B.O.B. bot has the lights that flash along face plate. It's a sequential blinking. Do you guys have any recommendations for lights, led, rgb or anything else so I can mimic it.

Thanks!

#35  

For the head rotation, I initially removed the tabs but the head did not rotate freely, it kept hitting the sides. So I shaved off the plastic using a belt sander. I also added foam to create friction.

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PRO
Synthiam
#36  

Hey - that's exactly what i did. I used a dremel to cut the plastic around the head disc. I didn't cut it very smooth... yours looks better :D

#37  

You should use a standard servo for head rotation. Micro servo won't last very long. Trust this with my experience.

#38  

Thanks Dj!

rb550f, I already burned one out! :-)

I'm using the servos that came with the EZ-B Kit for the shoulder, elbow, and claw. The elbow and shoulder servos both make a lot of noise. Should I try replacing them or counter the weight some how?

PRO
Synthiam
#39  

Oh geez - i didn't notice it was a micro servo. I agree with @rb550f

The HDD servos are best to use for the arms and elbow. Are your servos HDD or HD from the kit? depends what version of the kit you have. Look at the servo label

#40  

@Dj, these are HD. What are the specs on the HDD?

The sticker is the same as the ones listed here (HDD): https://synthiam.com/Shop/AccessoriesDetails.aspx?productNumber=7

PRO
Synthiam
#41  

HDD servos are the ones you want. The specs of the HDD servos are on the page that you linked to.

EZ-Robot Micro HDD's began shipping as of this month (February 2018).

PRO
USA
#42  

Oh that’s good to know on the micros! I need some if they are just as quiet as the standard HDDs

PRO
Synthiam
#43  

They are very very quiet

Canada
#44  

@fxrtst - Don't pull the trigger too quick! We're still working through the existing micro servo inventory. New Micro HDD's were used in complete robot builds that started as of last week. Loose micro's will still be the old ones for a bit.

PRO
Synthiam
#45  

Oooooh now that's good information to know:D Thanks alan!