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Hungary
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Hexapod Questions

Hello!

We are a hungarian father and his son (sorry for my poor english). I bought a EZ-Robot Hexapod for my son, who is interested in it.
I bought it from ebay. Unfortunatelly the seller suck me in - as it was advertised as new, and what we got was opened original box and 2 pcs. cracked house servos.
It was the begining of our story.

I'm a hardware development engineer, so I understand what the Hexapod does and why it is working and how ...

There are several problems what we don't understand, I list it:

1. We power on the Six, we connecting - it is working. After a simple movement/action the Six's 1 servo frequently vibrate and give rattling sound - not always the same. If I touch it with my finger I feel which one is vibrating.
Is it normal?
If I fine tuning the servos for 90, then the problem still exists.
What can I do with this?

2. I try the tracking function of the camera. I trained an object by Six, and if I try Six tracking this object it is locking the object and sometimes Six turn away about 30-40 from the locked object.
What I do wrong?

3. Mobile app
We have mobiles and tablets with several screen LCD resolution, but the deafult mobile app doesn't display perfectly on the screen, for example the left, forward, reverse, right buttons and main background image is not square rather rhombus.
What do I wrong?
OR why I can't change the main's width and height 800x480 pixels?

4. Can the servo's fine tuning values loading on power on to the Six?
We tried to calibrate the servos, but 2-3 couldn't set by mechanically, only by fine tuning.

So, that are the first problems for us. Could you help us?

PS: we live in Hungary/Europe, how can we buy servo for good price? The price is ok, but the shipping charges are very high, for example from Brookstone the shipping and custom charges are 3x more then the servo's price!

Best regards: Zsolt Tóth

AI Support Bot
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Synthiam
#1  
Some answers below.

Quote:

1. We power on the Six, we connecting - it is working. After a simple movement/action the Six's 1 servo frequently vibrate and give rattling sound - not always the same. If I touch it with my finger I feel which one is vibrating.
Is it normal?
If I fine tuning the servos for 90°, then the problem still exists.
What can I do with this?

It is normal for a servo under load to chatter or hum. Usually moving it a degree or so will quiet it down, but you will almost always have some noise coming from the robot even at rest.

Quote:


2. I try the tracking function of the camera. I trained an object by Six, and if I try Six tracking this object it is locking the object and sometimes Six turn away about 30-40° from the locked object.
What I do wrong?

Sounds like you have the pan and tilt servos reversed. Try swapping the two plugs with each other, although you may actually have the robot assembled wrong. The tilt should be the lower and pan (side to side) should be the upper servo.

Quote:


3. Mobile app
We have mobiles and tablets with several screen LCD resolution, but the deafult mobile app doesn't display perfectly on the screen, for example the left, forward, reverse, right buttons and main background image is not square rather rhombus.
What do I wrong?
OR why I can't change the main's width and height 800x480 pixels?

Please provide more information on the devices you are using. I have used EZ-Mobile on several Android phones and a Nexus 7 tablet without seeing this issue. Can't provide much other help unfortunately.

Quote:


4. Can the servo's fine tuning values loading on power on to the Six?
We tried to calibrate the servos, but 2-3 couldn't set by mechanically, only by fine tuning.

Six doesn't really need fine tuning. Basic calibration is good enough for all of its movements to work correctly. I would just delete the fine tune profile and use basic calibration (make sure all the levers are attached correctly).

Quote:


PS: we live in Hungary/Europe, how can we buy servo for good price? The price is ok, but the shipping charges are very high, for example from Brookstone the shipping and custom charges are 3x more then the servo's price!


You can buy directly from EZ-Robot. Shipping on just a couple of servos may be a lot. The bigger your order, the less the relative shipping cost, although EZ-Robot is not responsible for customs/VAT charges which vary by country quite a bit.
http://www.ez-robot.com/Shop/Default.aspx?CatId=104

You could also see if any of the European re-sellers here carry the servos and can do better on shipping: http://www.ez-robot.com/shop/retailers

Welcome to the forum, and sorry to hear that you got ripped off by an eBay seller. That must be very frustrating, but I think you will find a small investment in replacing the parts and some time reviewing the lessons and tutorials in the learn section of this web page will give you a long lasting and exciting hobby (note: if ordering Servos, I would order a couple of spares. They do occasionally where out).

Alan
#2  
Follow-up on fine tuning. It really is only needed for the JD robot or other humanoid type robots, which relies very much on being able to balance and have all of the movements execute perfectly. Six, Roli, and AdventureBot all work fine without fine tuning.

Alan
PRO
Synthiam
#3  
Thanks Alan - also, there is a very important section of the website titled LEARN. The menu option can be accessed in the top menu bar. Press learn and select your robot. There are instructions for your robot and manual pages for the software.

Welcome to the group:)
#4  
Dear Alan!

Thank you very much for your answers!
I have read the lessons...
PRO
Synthiam
#5  
Great!

EZ-Robot Revolution Six is a great learning platform. There is a great deal of information in the learn section to teach you about servos, programming and electronics. Since you asked about servos, here is a direct link to a fantastic tutorial which explains how servos work: http://www.ez-robot.com/Tutorials/Lesson/48?courseId=6

Keep in mind that ez-robot is unable to identify if your servos are damaged from the previous owner, or simply worn out from use. If the vibration is severe, then i would assume those particular servos are worn and will eventually require replacing.

However, if the servo is vibrating only slightly when weight is applied, the link above will explain why. Servos modulate an electric motor back and forth rapidly to maintain a position. Read the above link to see how servos work.
PRO
Synthiam
#6  
Alan, he's probably using the default six project - which is already configured for the tracking servos. I can only guess that the camera is facing the wrong way:) he put the camera on reversed.

If he pushes forward, I bet six walks backwards.

All he has to do is change the camera direction to be correct as per the instructions and voila!
#7  
I was thinking about Roli which has pan and tilt where i have seen this before. SIX the camera just sits on top of the body and the whole body moves. DJ is right, you probably have the camera on backwards.....

Alan
#8  
Unfortunatelly not, the camera is in good direction.

*********** UPDATE 2016.05.20 ************
Very good news!

1. Paypal granted me - because I was ripped off by seller, I got a FULL refund. ;-)

2. I solved the color tracking problem:


User-inserted image


User-inserted image


I think the solution was that I made a wider grid/ moved the grid lines!
#9  
Guys!

I ask who was Hexapod: what time it can play with till battery discharging at 6,6V?
It seems to me that this time is 1/2h appr.
#10  
Dear Alan!

Mobile devices we have problems: Jiayu G5 mobile phone (4.5 "IPS OGS HD (1280 × 720, 326PPI) Gorilla Glass 2), Vido N70HD tablet ( 7" IPS HD (1280 × 720)), Teclast X98 Air 3G tablet (9.7-inch IPS IGZO Retina display with a resolution of 2048x1536)

On our devices we couldn't reach the right side of the application, because it oversized the screen, we can only scroll up and down but not left or right:
Mobile app

Here are my devices:

User-inserted image



User-inserted image


Any idea?

Thank you.
PRO
Synthiam
#11  
Due to lack of standardization of android devices, it is impossible ez-robot (or any app developer) to verify compatibility. As you can see from using this product and joining the community, no one has ever experienced a similar issue. This leaves the issue isolated to your device.

I would recommend verifying the device has not been modified and settings to the display DPI is original state. If you are unsure, a factory reset to default settings is recommended.
#12  
Thank you for your answer. I tried to change the DPI earlier but no resolution...
PRO
Synthiam
#13  
That is unfortunate - i will add a note to see if there is anything that can be done from our side for the next release of ARC mobile.
#14  
@tkristof
Hello, and welcome.

Have you tried pinching in on the image to insure it is not accidentally expanded?

As a temporary solution you could resize the layout of the mobile window. Every component is fully adjustable, including the font. The only thing that is not is the background image. This image gives the direction buttons that blue diamond shape background. You can delete that. That way the background will not be off in relationship to the buttons.

After that you can make all the other controls smaller and bring them closer together so that they can all appear within the screen area of the tablet. Of course you don't want to make things too small, but a little off each can add up. To keep from making the font too small to read in smaller button boxes you could abbreviate some of the longer texts. Plus you can make some two lines instead of one, making the buttons more like a square than a rectangle.

The Camera screen area can be made smaller and the sliders could be moved under the buttons in the upper right area. That would allow you to move the
buttons in the lower right area under the video screen area. Some of those buttons could also be moved under the sliders to allow the mobile window to be smaller in height. And, naturally, you can simply eliminate some buttons you are not that fond of.

Just a few suggestions. I'm sure you can figure it all out. Basically, make things fit whatever the screen resolution is for each device.

I believe each device can have it's own, individual copy of the mobile screen, so you could upload a different one for each tablet.
PRO
Synthiam
#15  
@wbs - that's what is strange... the screen resolution that is returned by the device is used as a multiplier for all objects. The dimension of ARC mobile apps is 800x480. No matter what the resolution is of the mobile device, the code uses a multiplier.

so if your button is 100x100 pixels in ARC, and the resolution of your device is 1600x960, the multiplier would be 2, which makes the button 200x200 on the device.

It's a very simple calculation that is performed on all objects - which is why the same mobile app works across most mobile devices and tablets... and why this is the first time anyone has had this experience.

The only thing i can think of why this particular Android device is displaying incorrectly is due to the driver returning the incorrect size of the display - which should be impossible. However, who knows what issues exist in that particular android version because there is absolutely no requirement/control of android distributions. That's why mobile developers have a difficult challenge supporting android devices.

I'm mostly confused of how this can be displaying so strangely on two separate devices... *confused*
#16  
@DJSures

I see. So it should be adjusting itself to whatever the resolution is (or says it is). But, does that explain why the direction buttons are offset from the blue diamond background? Regardless of what it says vs what the real resolution is, should it not have adjusted itself such that they would stay in alignment?
PRO
Synthiam
#17  
No - The blue triangle is the background image, which is also not scaled correctly.

The background image should fill the screen based on the resolution returned by the driver.

I'd be interested to see what resolution was returned by the driver. I might have to make a version of the app that logs the driver resolution.
PRO
Synthiam
#18  
Update your android app to the latest version. The new version uses a different density multiplier for the screen resolution, which i hope resolves the issue on your device. Also, when the app loads, the Application Log will display the detected resolutions - please let me know what the resolutions are from the application log if there is still a rendering misalignment issue.
#19  
DJ Sures - Thank you, IT IS PERFECT! I tried on 3 android device.

One little problem stay on one device 1st picture of #11 post: there is not red circle spot in the blue rectangle which is the STOP function!

On the 2 other device everything is perfect!

Big thanks from Hungary to you. :)
PRO
Synthiam
#20  
Are there any errors in Application Log after loading Six project?