Construct the robot: what to buy?

Hello.

I want to construct a robot. I've found the chassi for 3D printing and am going to use mecanum wheels. And of course I need some stuff from Arduino. Please, help me to choose.
Of course, at the begining I just expect my 4WD robot to move :slight_smile: But later I hope in will avoid the obstacle, correspond(send and receive data) with something else. I also would like it to film video and maybe send to phone. Coordinate identification via GSM will also be good. And I'm thinking of connecting everythin to both battaries and solar cell.
I understand that I'll have to code a lot, but at first I must buy something.
For now my list is as follows

  1. Arduino Uno Rev3 Is it enough for me? Or Arduino DUE? Or Arduino Mega 2560 Rev3?
    http://store.arduino.cc/product/A000066
  2. Arduino Motor Shield Rev3. Do I have to buy two of these?
    http://store.arduino.cc/product/A000079
  3. Arduino GSM Shield (antenna connector)
    http://store.arduino.cc/product/A000044
  4. Arduino Wifi Shield (antenna connector)
    http://store.arduino.cc/product/A000089
    5.1) Small DC motor. I'll have 90mm wheels. Should I buy big DC motor? I'm planning to buy four of them, of course.
    http://store.arduino.cc/product/T010160
    5.2) Kysan 1124090 Nema 17 Stepper Motor. Maybe this one will be better for me?
    http://store.arduino.cc/product/MK00742
  5. Analog 180° Micro Servo to rotate 7)
    http://store.arduino.cc/product/T010050
  6. PING))) Ultrasonic Distance Sensor
    http://store.arduino.cc/product/MK00671
  7. Breadboard and Wire Kit. I think I'll need this, right?
    http://store.arduino.cc/product/M000005
  8. Wifi Antenna
    http://store.arduino.cc/product/X000006
  9. SM Antenna ANTA7000A0200BD1
    http://store.arduino.cc/product/X000005

What did I miss and what is redundant? This will be my first robot, so I will not buy everything at once. Help me to choose what to buy and what to buy at first, please.
I will be greatful for any other suggestions.

  1. Arduino UNO is not enough, think about Mega 2560
  2. it is expensive and too big, there are better solutions.
    5.1) DC motor is ok, but you need also gears and possibly encoders.
    5.2) Forget about stepper motors, they are not for wheels.

EL-Costello:
I recommend this ......

Since you are a principal in that venture, I think you should say so in your "recommendation".

What encoder do You recommend?

What about a motor like this one?

  1. it is expensive and too big, there are better solutions.
    Can You please give a link to the solutions that You mentioned?
  1. Arduino UNO is not enough, think about Mega 2560
    Can I easily use my code, written for Arduino uno, for programming Mega2560?

@El-Costello, now I look like a jackass since my previous post quotes non-existent text; thanks for that.

I didn't say you should remove your recommendation, just that I thought you should say you had an interest in the venture. Terry King often recommends his own stuff in his posts, and always points out it's stuff from his shop.

I hadn't a chance to read "the non-existent text".

What tasks that I mentioned in the first post can I accomplish with Arduino UNO?

JimboZA:
@El-Costello, now I look like a jackass since my previous post quotes non-existent text; thanks for that.

Sorry for that, really. I did not use forums for long time.

Lyubomyr:
What encoder do You recommend?

I would recommend this: https://solarbotics.com/product/gmww02/

Lyubomyr:
What about a motor like this one?
DFRobot 6V,180rpm Micro DC Geared Motor with Back Shaft - RobotShop

Yes, it's a good one, but if you use the encoder mentioned above, you'd better use this one: Gear Motor 2 - 224:1 Offset Shaft - Solarbotics Ltd.
Keep in mind that there are different gear ratios. Also I must say that the motor you found, the motor I suggested and also the mentioned encoder are rather for indoor use.

Lyubomyr:

  1. it is expensive and too big, there are better solutions.
    Can You please give a link to the solutions that You mentioned?

If you gonna use GM motors than use this dual driver. Pololu - DRV8835 Dual Motor Driver Carrier. It costs $5 and easy to use.

Lyubomyr:

  1. Arduino UNO is not enough, think about Mega 2560
    Can I easily use my code, written for Arduino uno, for programming Mega2560?

Definitely yes. The only thing you would need to change is pin numbers. In very simple words UNO is the same as Mega2560 with less pins.

P.S. As to deleted text - I sent a copy to you as a private message.

Lyubomyr:
I hadn't a chance to read "the non-existent text".

What tasks that I mentioned in the first post can I accomplish with Arduino UNO?

Ok, lets count. You need:

  • one I/O and one PWM pin for each motor (4 for 2WD and 8 for 4WD).
  • one PWM for servo (1)
  • one PWM (or I/O?) for Ping))) (1)
    And you still have some pins for LEDs (personally, I like to use LEDs to see the status of some process) and other minor stuff.

For the sake of moving and orientation UNO is more then enough, but if you like to have something else, then you will need more pins.

Thank You very much for Your answers.

Please, tell me is DRV8835 Dual Motor Driver Carrier (Pololu - DRV8835 Dual Motor Driver Carrier) fully compatible with both Arduino Uno and Mega?
I don't understand why it costs less? It is smaller. Does it have the same functions as Arduino Motor Shield Rev3? Is it worse in some other way?

Those Pololu motor drivers are excellent. I have a 2130 which is mentioned in that link as similar to the 2135.

They are better than those boards and shields which use the L298, because the L298 is old technology and is very inefficient.

Lyubomyr:
Please, tell me is DRV8835 Dual Motor Driver Carrier (Pololu - DRV8835 Dual Motor Driver Carrier) fully compatible with both Arduino Uno and Mega?

Yes, it is compatible with anything generating PWM and digital signal (so Uno and Mega too).
I use it in my robots and have no any troubles at all, it just works.

Is a cable for my Arduino (UNO or MEGA) an ordinary usb cable? Or is it some special Arduino cable?

I need to rotate my four wheels in the different direction at the same time to improve turning of the vehicle. Is it possible with DRV8835?

Lyubomyr:
Is a cable for my Arduino (UNO or MEGA) an ordinary usb cable? Or is it some special Arduino cable?

The Uno has the square usb-b printer-style connector, but the cable's just a standard one, nothing special to Arduino.

Lyubomyr:
I need to rotate my four wheels in the different direction at the same time to improve turning of the vehicle. Is it possible with DRV8835?

Pololu's page says this:

Texas Instruments’ DRV8835 is a tiny dual H-bridge motor driver IC that can be used for bidirectional control of two brushed DC motors at 0 V to 11 V.

...... so birectional for 2 motors so you would need 2 DRVs for 4.

Lyubomyr:
I need to rotate my four wheels in the different direction at the same time to improve turning of the vehicle. Is it possible with DRV8835?

Pololu's page says this:

Texas Instruments’ DRV8835 is a tiny dual H-bridge motor driver IC that can be used for bidirectional control of two brushed DC motors at 0 V to 11 V.

...... so birectional for 2 motors so you would need 2 DRVs for 4.
[/quote]

I have seen this at Pololulu site. But the question is: what does bidirectional mean? Two forward at once than two backward at once or one forward and other backward at the same time?

I have seen this at Pololulu site. But the question is: what does bidirectional mean? Two forward at once than two backward at once or one forward and other backward at the same time?

You need to read a bit lower down the page. In either operation mode (phase/enable or in/in), the two motors A and B are independent of each other: the tables show motor "x" where "x" is A or B and you control them separately.

8835.PNG

Thank you very much!

Which one is better Arduino Due or Arduino Mega 2560?

Or should I compare Arduino Due with Arduino Mega ADK Rev3?

Which one is better Arduino Due or Arduino Mega 2560?

Based on what criteria?

Or should I compare Arduino Due with Arduino Mega ADK Rev3?

Do you plan to use an Android?