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11
Software / Re: Controlling robot using its graphical 3D model
« Last post by amrtaha on February 25, 2015, 07:23:59 PM »
Thanks guys for the caring to answer, and i will go check the blender software right now!!
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Misc / Re: hobbyist for hire?
« Last post by dmehling on February 25, 2015, 05:42:11 PM »
There is a little bit of margin on the right and left sides of the screen where there is no text, so I could lay the conductive material in that area and it would not cover any text.  I guess what I need to figure out is how much voltage and current should be applied to the conductive material.  I saw a video of someone using this method with just a wire going from one of the pins of the microcontroller to the conductive material.  So I would assume that is about 3.3v and current might be 40 mA, at least that is the current output for some of the microcontrollers I have looked at.
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 8) Cool!  8)
I have just acquired a Ardunio bare bones MCU board, and plan to
start programming soon. I saw some code on Youtube, and it looked like
a C program, with javascript.(?) Very similar to programming a beagle bone black.
What I would do is set up a test fixture, to make sure everything is working, then
devise the housing for the robot.(unless you already have a plan)
I was wondering, How many instructions per second does the ATmega328 process?
The ATmega328 would be great for the dedicated processes, and coupled with a
beaglebone or Raspberry PI, is a powerfull combination. For input/ooutput protection,
I use optocouplers to protect my microcontroller. More circuitry is required, but you get
attached to your robot after spending alot of time.(do not want to see it go, POOF!)
Sooner or later, I am going to make a robot to cook my eggs and bacon, like on
the movie, Chitty, Chitty, Bang Bang!
Keep Me posted.......... ;D ;D ;D ;D
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Misc / Re: hobbyist for hire?
« Last post by mklrobo on February 25, 2015, 04:49:13 PM »
 ;) Interesting!
That part of the screen must be dedicated to actuating the
page turning. Hopefully, this will not take away from your
reading. I have not heard of this, but I am sure it is possible.
You will probably have to tweek this out too; but it sounds like
it will be less difficult. I will check around to see if I can find
somebody doing this. Keep me posted...  ;D ;D ;D
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Misc / Re: hobbyist for hire?
« Last post by dmehling on February 25, 2015, 04:22:58 PM »
I just discovered that there is a much simpler method of simulating a touch on the screen, which will completely eliminate the need for actuators.  I didn't really think about the fact that the Kindle has a capacitive touch screen and not a resistive screen, therefore it doesn't depend on pressure to be activated.  I just read that you could place a piece of tinfoil or some other conducting material on the screen and run some power to it from the microcontroller, and that would simulate a finger press.  I'm not completely sure yet how to implement this, but it should be easier than using a servo.
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Challenge:
To connect encoder outputs that will provide error feedback to a microcontroller of a four (4) wheeled Bot.

Background
I am in the process of laying out a circuit connection board to support battery power distribution to motor drivers whose outputs will be returned to the connections board to be wired to the six (6) wire connectors from the motor encoders; then the A and B encoder outputs will be distributed to a Pi Hat (custom Arduino Uno) fitted with LS7184 clock converters whose outputs will be wired to the ATmega328 microprocessor.  Wow that is a mouthful!

The Bot motors will be powered by two (2) 6V 3300mAh battery packs in parallel and fused at the connections board.

The Pi will communicate with the Arduino using I2C via a MCP23017, and the Arduino will control the motor speed and direction using PWM.

Summary of Components and Processes in Play
>Four 75:1 geared 6V DC motors with 6A stall current and 48 CPR Hall Effect encoders

>Four (4) Pololu motor drivers #1451which are matched to the DC motors – to save microcontroller I/O lines the PWM input pin of the driver boards will be held “high” by connecting them directly to the 5V VDD supply to the driver board.
 
>LS7184 clock convert(s) - at this point I am not sure how many LS7184 will be needed or if this is the best way to interface the encoder signals with the microcontroller.

>Custom Arduino Uno Pi Hat (bare bones Arduino) using Atmega328 microcontroller with 16KHz crystal.

At this point I am not concerned with code, I will deal with that big challenge down the road.  My focus at the moment is on completing the Pi-Bot's circuits, modules, (power supplies, GPIO interfaces for the Pi and Arduino, etc.), circuit board, motor, and battery locations (bottom of 1st deck, top of 1st deck or 2nd deck of the chassis) and how best to connect everything to facilitate charging batteries, modifying and servicing the Bot.

That said, I need advice and guidance to help me complete a connection board wiring plan with regard to how to connect the A and B outputs from the encoders to the clock converters and then the LS7184 to the ATmega328.  Of particular interest are pin numbers that should be used to connected the LS7184 to the microprocessor any any pull-up, pull-down or protection circuits that should be used.

The above Bot concept sounds good on paper, at least to me, a relatively uninformed robot newbie!

Therefore, comments with regard to the above Bot operational concept, in addition to the needed wiring advice, would be greatly valued.

Cheers,
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Software / Re: Controlling robot using its graphical 3D model
« Last post by mklrobo on February 25, 2015, 11:29:55 AM »
 8) Cool! I will have to check out the blender software!  8)
18
Mechanics and Construction / Re: pots
« Last post by mklrobo on February 25, 2015, 10:31:39 AM »
 :) Hello!
There are alot of different methods for using a pot to control a robot motor; and thus,
a robot joint.
If you want to control a robot joint, then the pot has to be mounted such that it can
move linearly when the joint is moved.
If you want to control a robot motor, then a pot (likely) is mounted remotely,
an controls the motor.
An Analog to digital process can be used to assign power levels,movement in degrees, or any number
of directions that you may want to use, to direct/control your robot joint.
Most robot kits are straightforward with this, and provide programming and free software to program
your robot. I recommend you visit the Forum at Parallax.com, and read some of the threads there,
as they are helpful. This investment in time could answer some questions, and save you heartache. :'(
You can search this forums postings, as it might be already answered by another member. Good Luck!
 ;D ;D ;D
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Mechanics and Construction / pots
« Last post by ruddock1234 on February 25, 2015, 08:05:49 AM »
would anyone know how a pot is used to control a robotic joint
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Misc / Re: hobbyist for hire?
« Last post by mklrobo on February 25, 2015, 07:05:34 AM »
 :) Hello!
I agree with your assumption that you will need a lower torque servo.
At this point, you have a ballpark idea of what you want to do, just the
"tweeking out"  is needed. It seems that the critical part of the robot finger
is going to be the screen touch sense, in which you will probably want to
have two; one for the screen, and one for an overpush limit.
Keep me posted....  ;D ;D ;D
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