Arduino Robot Project

[GRB352]

Once I started on the 3d printer path I wanted to drop any and all other project to focus attention and projects budget in one direction. But It's kind of stressing me out lately so I'm starting another for stress relief. My nephews had two of these at christmas http://www.wowwee.com/mip/ and I thought it was fun to make them fight, but there were a few let downs.

Project Goals

spend at little money as possible

Arduino platform

remote control

laser tag combat

camera targeting

possible multi-user gaming (ie one driver multiple gunners)

I started with a mega 2560 (from my 3d printer inventories) and e300 razor scooter I scored at a yard sale ($10) and modified the electronic speed controller to allow the arduino to control the speed (5v mosfet). I will need a few more scrounged parts, but to build a R/C vehicle is easy. There will probably need to be some creative 3d printing to make square holes for my square pegs, and round holes for my round ones, but I think I know a guy for that.

The part that was going to be a challenge, was making a control interface. What I wanted initially, was to get a wifi module, or ethernet module with a 802.11 bridge for the arduino, and then use a Android software devkit to make an app that changed values on the arduino over the wifi. This would be preferable over bluetooth, mostly for the range, but also for video bandwidth.

With this framework, I think that idea would work, but it isn't quite out yet:
https://www.kickstarter.com/projects/167134865/blynk-build-an-app-for-your-arduino-project-in-5-m/

MIT's App Inventor 2 is out and also looks like it will work, but it doesn't seem to use the network, only bluetooth
http://appinventor.mit.edu/explore/ai2/tutorials

I think that I can live with bluetooth for control, and then have a second 802.11 network for any video needed in the future. 

So BT control it is, but if I am going to live with BT, then I have some other options, If I go BT host I can get going easy, and add in network later if needed:

https://barrettsprojects.wordpress.com/2013/01/12/usb-host-shield-demonstration/

USB host libraries will get me access to the BT module, then I have a choice of libraries for different types of controllers.
https://github.com/felis/USB_Host_Shield_2.0

I have one of these on the way:

http://www.aliexpress.com/item/Free-shipping-USB-Host-Shield-compatible-with-Google-Android-ADK-support-UNO-MEGA-for-arduino/1941868502.html

http://www.aliexpress.com/item/4-Mini-Bluetooth-adapter-laptop-desktop-computer-Bluetooth-mouse-and-keyboard-sound-general-Headset/32311359086.html

[Jeffrey Schwartz]

Check fdroid.org, there's a couple Android/Arduino open source apps there.

--
You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.
To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hacke...@googlegroups.com.
To post to this group, send email to gainesville...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/bc48bf00-9f83-428e-906d-55c032a7f8d0%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[GRB352]

I found this there:

https://f-droid.org/wiki/page/com.primavera.arduino.listener

https://github.com/jeppsson/Arduino-Communicator

But it looks a little too DIY for my skill level. I can see how it will work, basically just reads and writes the serial data just as I need. But then I have to figure out the GUI part.

MIT App Inventor 2 is kinda confusing, but with all their guides I think I can get there. Blynk looks like my mother could do it.

[Jeffrey Schwartz]

I've gotten to really enjoy SL4A/Python https://code.google.com/p/android-scripting/

Using it in conjunction with Tasker makes some really neat toys

And Tasker has the Zoom plugin, which lets you make GUIs

I'd imagine you could write something in python that does communication to the robot, and have it run either webview or Tasker for GUI

--

You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.
To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hacke...@googlegroups.com.
To post to this group, send email to gainesville...@googlegroups.com.

To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/2a90c576-1611-43bd-8205-d5dae185804a%40googlegroups.com.

[GRB352]

On ESC control

Initially I was thinking of using the electronic speed controller (ESC) from the E300 24v scooter.  

The ESC works by taking a input of 0V-5V and using that reference voltage to know how much of the 24v to let through to the motor. So I attached the ESC to one of the ardunio's PWM output and wrote code to have the voltage from that pin slowly scale up and down from 0v to 5v and then hooked up my multimeter to make sure that was happening.  The made the motor slowly speed up, then slowly stop. The output uses a value range of 0 to 255, 0 being 0v and 255 being 5v.

So I added a potentiometer to an analog input, and set the arduino to read its state. it has an input range of 0-1023, 0 being knob off, 1023 being fully turned. I then divided the result by 1023 to find what percent the knob is turned. so if I got a result of 500, I would know the knob was set about 1/2way.

I then changed removed the code that scaled the power up and down between 0v-5v for the ESC, and had it set the power output to the same ratio as the knob. This made the knob control the ESC.

Not to confuse things, but 0-120 out of 255 didn't do anything for the ESC, so after some help from Brian@HS I found that what I needed to do, was scale that 0-1023 between 120-255 not 0-255. 

  oscope = 135 // (255-120)

  pval =  (float) val / 1023;

  wval1 = pval * oscope ;

  wval = wval1 + 120 ; 

That (float) part was another part I had help with...I needed the decimal points.

This is how I made the arduino control the ESC. I plan to use something besides a knob of course.

[Christopher Hoffman]

Not to confuse things, but 0-120 out of 255 didn't do anything for the ESC, so after some help from Brian@HS I found that what I needed to do, was scale that 0-1023 between 120-255 not 0-255. 

  oscope = 135 // (255-120)

  pval =  (float) val / 1023;

  wval1 = pval * oscope ;

  wval = wval1 + 120 ; 

Arduino has a handy map function for that: You specify input range, and output range and it'll do the math for you.

map(pval, 0, 1023, 120, 255).

Glad you are getting it to work though!

[GRB352]

on H-bridges

As it turns out, I don't want to use the electronic speed controller (ESC) from that scooter, because I will be needing reverse. to get reverse I will need an H-bridge. They are controlled the same way (0v-5v) but they also have switches for reverse, and some have brake (motor lock).

It was suggested that since the components for an H-bridge are pretty cheap and the circuit is pretty simple that I should build my own. However, I consider this slightly outside of my skill comfort zone so I plan to purchase a completed h-bridge module. I know I could take components from a kit and assemble them, but knowing which component to choose and where it should go isn't really in my skillset. 

These were some of my h-bridge options for my 24v (17A)  motors

$22 MC33886 Dual Hbridge 36v Peak 30A but only rated at 15a 

http://r.ebay.com/1Z7ohc

$12 BTS7960B 43A up to 27V

http://r.ebay.com/FIAfeQ

If I was doing something small, this would be an option:

$3 Dual H Bridge L298N (2A)

http://r.ebay.com/iXlyx3

but I ended up with this one ($27): 
http://www.aliexpress.com/item/High-power-20A-H-bridge-dual-motor-drive-module-machine-car-driver-board/2042900822.html

the $27 kind of blows my budget...oh well. 

[GRB352]

nice! I will try that when my h-bridge comes in.

[GRB352]

It doesn't look like the laser tag part will be all that difficult either:

Here is my first attempt:

https://youtu.be/P4sitH2YmrQ

I got part of the idea after seeing CVK using a led as a light sensor for one of his projects...I always figured I would need special sensors and special chips that did things I didn't understand...nope.

[matteroflight]

This is way cool!  Are you going to do a class on what you've learned? ^.^

--
You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.
To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hacke...@googlegroups.com.
To post to this group, send email to gainesville...@googlegroups.com.

To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/f1a9a5f9-e0e0-4ded-9353-c9ecd2e111bf%40googlegroups.com.

[Robert Burns]

Many of our members and guests confidently know they have some of the skills needed to do this, and think the other parts are too difficult or too expensive.

I'm hoping this thread will help cure the root causes of learned makelessness. First by spoiling the perceived difficulty of building a nerd-class robot, and how much room for creativity there is. Then by showing that it can cost way less than you would think. 

Then I will school them on the battlefield. 

[Jim Thompson]

Very cool. You could also use IR LED and a cheap dollar store flashlight body with focusable lens for a wider beam (easier to hit, especially at long distance). You would use a cheap IR sensor like in a tv. We have a simple arduino laser tag gun that uses this setup. I could share our circuit with you if you were interested. Basically you need the following two items and you could probably get it up and running in no time. http://www.adafruit.com/product/388 and http://www.adafruit.com/product/157 . Adafruit has some good library and tutorials on how to use the IR sensor and LED. https://learn.adafruit.com/ir-sensor

Keep up the awesome work.

[Robert Burns]

IR LED's eh? I have some of them somewhere. I seem to recall there is less chance of bright lights setting them off. I will play with that. Attached are the promising items I was able to dig out of my horde. Sadly the NES light zapper does not actually shoot out any light...that would have been too cool. The other is a serial IR receiver for a packard bell remote control., and a radioshack IR to RF remote bridge....with no remote. but it looks to have a large IR collector. 

I was thinking of using cheap laser pointers that come with those useless tips that make the laser pointer come out in a shape. But maybe a combination IR and Red LED receivers, or maybe the IR led will signal if it is hit by laser....fun!

A simple receiver is probably best, but some thing like this has interesting possibilities. Such as parts of the battlefield showing blink patterns that the user can drive a sensor up to and have ammo/energy reloads transmitted, or weapon upgrades (enables wide-IR beam,etc)....maybe even a class of robot that tries to run "All up on" another bot while it is occupied and takes control (or power, etc) by interfacing with a sensor.

http://www.instructables.com/id/Laser-Transceiver/
or
https://youtu.be/2yxwmSS6wrA

so much room for creativity. I really want more game than just two robots seeing who can blast each other faster. 

Thanks for the heads up on those parts, Adafruit makes great tutorials which is important, because I only know enough to be dangerous. If you are free on tuesday, bring some of that laser-tag stuff by to show off :-)  If you wont be free tue, I would still love to check that out sometime.

[Robert Burns]

So far the electronics part of this project is not going well. The dual H-bridge arrived with the tops of all the chips sanded off, and a different shape than the 20A shown in the item listing. This is not a good sign. Also the USB host shield (red board) is either DOA or uses a different pin configuration than the boards used by the Arduino USB Host library's authors.  I will be sending that one back and have purchased one from a seller the authors recommend (themselves). 
https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino/

 

I played with what IR stuff I had laying around. While I didn't make much progress here, I did come up with some cool IR/laser blaster idea's. I especially like how the inside of that Nintendo zapper uses the same button/switch as an arcade machine. I would like to design a 3d printed part that has a mount for the same switch, and plug inline with PVC to make easy, cheap IR/laser blasters. Before I put too much work into any of the laser tag stuff I started thinking it might not be such a great idea afterall. I doubt the Property Managers want people running around the Sun Center, pointing things and blasting each other. So there probably wont be any need for hand held blasters. 

 

Now the Mechanical side I have made some progress. I started off with one of these:

I've been carting it, and a spare motor of the same size around for the past couple years in hopes of using it for something fun. I planned on mounting both motors side by side on the frame and moving both wheels to the back and connecting one wheel to each motor on an extended axle. I could then easily add on two castor wheels for the front, and it would drive like a tank. After more discussions with people at the project nights it really seems easier to just leave everything where it was already meant to be, but find a 2nd scooter and connect them like a catamaran. This would negate the need for a ton of work. Really, now it is just a simple welding of a metal bar across two scooters after removing the handlebars and mechanical brakes. 

I stopped by Solano Cycles (right near the HS, on south main) and asked if they had anything in their junkpile that I could use.Rob over there was super cool. I was able to score 3 more scooters that wanted second lives as robots.

  

Over the next week or so I stripped them down  as time and the sun permitted. There is about 1hr of each day that the sun isn't blazing too hot, but not yet so cool the mosquito's from the nearby prairie come out in full force.

  

A ton of good, useful parts. But I don't really have 2 perfect matches for a catamaran style scooter-bot. Craigslist is showing several options here for razor scooters with dead batteries. Hopefully there will one that is both cheap, and blue ;-)

More Pictures here
​

Salvage Arduino Robot32 photos

​

[GRB352]

I scored a 2nd blue e300 razor from craigslist. I was hoping to just connect the two scooters, but it looks like the shape of the front wheels wont quite work for that. The need to be "castor wheels" so they will swivel properly when the bot turns using differential drive. with their current shape, they could swivel unpredictably.

Rather than modify the front wheels, I think they will be removed and then replaced by large castor wheels

Great video demo of what I plan to use for control.

https://youtu.be/Sa68Vw-a9KI

My replacement usb host shield arrived.  I was able to pair with a wii remote, and the serial monitor shows when buttons are pressed. Now I just need some free time to work on that some more. 

[GRB352]

https://youtu.be/esbBgERQYHA

With all of the recent robot talk at the hackerspace I put a little bit of time back into this old project.

Here is a video of my working controls

[Frank]

Very cool, please bring it Tuesday for a closer look.

Thanks

Frank

Sent from my iPad

> --
> You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hacke...@googlegroups.com.

> To post to this group, send an email to gainesville...@googlegroups.com.
> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/cf2f3b68-cfd0-4659-ba26-7aa698ad4035%40googlegroups.com.

[Jeffrey Schwartz]

On the topic...

Thanks for the answers I got on the Arduino relay question the other day.

Here's what it was for :
https://youtu.be/4YeEoslEmC4

I've got the two drive motors running nicely, using a pair of relays
for each motor as an H-Bridge.
I'm planning on using 2 more relays for the head rotation motor,
leaving 2 relays.
The original body has flashlight bulbs in the eyes, so I'm strongly
leaning toward using one relay for that.
Last relay is undecided.

Next step is Bluetooth to link to my cell phone, running SL4A Python.
Step after that is at least 1 ultrasound range finder, for object
avoidance, and bumper switches for when it doesn't see the obstacles.

I'm playing with the idea of a 3-of-8 decoder into a second relay
board, and using that to control the motors in the arm, and maybe some
other items.

> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/02B21B2B-DE0B-479C-8271-4299C293EE8C%40gmail.com.

[damion...@gmail.com]

Nice work ! My friend had an Omnibot 2000 and we all thought he was rich.
Damion

> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/CAL943ar_Q6z807Ks-d-2T9peBzAshGxDXtFEi-mb3zyHWJfNRA%40mail.gmail.com.

[Jeffrey Schwartz]

Picked this one up at a garage sale a long, long time ago.
Electronics on it went sour, but the motors work.

> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/66BE5AC1-321E-40A8-816E-EE5EF0B250B7%40gmail.com.

[GRB352]

nice! your robot looks like a robot, glowing eyes would help. I mean, anything to make it look terrifying is a good idea ;-)

really your robot will be more robot than mine. I don't plan on making it autonomous, more like a jumped up RC vehicle. 

>>>> To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hackerspace+unsub...@googlegroups.com.

>>>> To post to this group, send an email to gainesville...@googlegroups.com.
>>>> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/cf2f3b68-cfd0-4659-ba26-7aa698ad4035%40googlegroups.com.
>>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>> --
>>> You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.

>>> To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hackerspace+unsub...@googlegroups.com.

>>> To post to this group, send an email to gainesville...@googlegroups.com.
>>> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/02B21B2B-DE0B-479C-8271-4299C293EE8C%40gmail.com.
>>> For more options, visit https://groups.google.com/d/optout.
>>
>> --
>> You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.

>> To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hackerspace+unsub...@googlegroups.com.

>> To post to this group, send an email to gainesville...@googlegroups.com.
>> To view this discussion on the web, visit https://groups.google.com/d/msgid/gainesville-hackerspace/CAL943ar_Q6z807Ks-d-2T9peBzAshGxDXtFEi-mb3zyHWJfNRA%40mail.gmail.com.
>> For more options, visit https://groups.google.com/d/optout.
>
> --
> You received this message because you are subscribed to the Google Groups "Gainesville Hackerspace" group.

> To unsubscribe from this group and stop receiving emails from it, send an email to gainesville-hackerspace+unsub...@googlegroups.com.

[Jeffrey Schwartz]

Thanks!

I saw a thing where a gent used multiple Arduino's to make a robot.
His starting base was one of those hand-cart sized battery jumpers for
a mechanics shop.
It had a bunch of functions - "follow me" was one, and he'd set it up
with jumper cables, USB, 12v cig lighter, and a 120vac inverter. So
he'd just have it follow him around while he was working in his shop,
and provide power as needed.

That's one thing I want to do with mine.

I saw the Google Cellbots site years ago, and realized that a cell
phone is a heck of a thing for robotics... and I wrote this Siri-ish
thing for my Android. I started working on it before Siri came out,
and it was intended to be more proactive since voice recognition stank
back then. It reads GPS, time of day, calendar, email , and then makes
smart ass comments on my life. I tell people "I'm so messed up that
other people can hear my invisible friend."

So, my 'invisible friend' has been jonesing for a robot body for a
while...and now it's getting there.

>> >>>> send an email to gainesville-hacke...@googlegroups.com.

>> >>>> To post to this group, send an email to
>> >>>> gainesville...@googlegroups.com.
>> >>>> To view this discussion on the web, visit
>> >>>> https://groups.google.com/d/msgid/gainesville-hackerspace/cf2f3b68-cfd0-4659-ba26-7aa698ad4035%40googlegroups.com.
>> >>>> For more options, visit https://groups.google.com/d/optout.
>> >>>
>> >>> --
>> >>> You received this message because you are subscribed to the Google
>> >>> Groups "Gainesville Hackerspace" group.
>> >>> To unsubscribe from this group and stop receiving emails from it, send

>> >>> an email to gainesville-hacke...@googlegroups.com.

>> >>> To post to this group, send an email to
>> >>> gainesville...@googlegroups.com.
>> >>> To view this discussion on the web, visit
>> >>> https://groups.google.com/d/msgid/gainesville-hackerspace/02B21B2B-DE0B-479C-8271-4299C293EE8C%40gmail.com.
>> >>> For more options, visit https://groups.google.com/d/optout.
>> >>
>> >> --
>> >> You received this message because you are subscribed to the Google
>> >> Groups "Gainesville Hackerspace" group.
>> >> To unsubscribe from this group and stop receiving emails from it, send

>> >> an email to gainesville-hacke...@googlegroups.com.

>> >> To post to this group, send an email to
>> >> gainesville...@googlegroups.com.
>> >> To view this discussion on the web, visit
>> >> https://groups.google.com/d/msgid/gainesville-hackerspace/CAL943ar_Q6z807Ks-d-2T9peBzAshGxDXtFEi-mb3zyHWJfNRA%40mail.gmail.com.
>> >> For more options, visit https://groups.google.com/d/optout.
>> >
>> > --
>> > You received this message because you are subscribed to the Google
>> > Groups "Gainesville Hackerspace" group.
>> > To unsubscribe from this group and stop receiving emails from it, send

>> > an email to gainesville-hacke...@googlegroups.com.

>> > To post to this group, send an email to gainesville...@googlegroups.com.
>> > To view this discussion on the web, visit
>> > https://groups.google.com/d/msgid/gainesville-hackerspace/66BE5AC1-321E-40A8-816E-EE5EF0B250B7%40gmail.com.
>> > For more options, visit https://groups.google.com/d/optout.
>

> --
> You received this message because you are subscribed to the Google Groups
> "Gainesville Hackerspace" group.
> To unsubscribe from this group and stop receiving emails from it, send an

> email to gainesville-hacke...@googlegroups.com.
> To post to this group, send email to

> gainesville...@googlegroups.com.
> To view this discussion on the web, visit

> https://groups.google.com/d/msgid/gainesville-hackerspace/5560c489-b655-4309-aea5-ce7547ffad92%40googlegroups.com.