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### Topic: Mobile Robotic arm Programming  (Read 1 time)previous topic - next topic

#### movinperera

##### Jan 12, 2017, 06:02 am
Hello World!

I recently built a mobile robotic arm (for the college science exhibition) with 2 DC gear motors hooked up with the 2 wheels (the other two wheels are universal) and 4 Servos in the arm (including the Gripper).

I used an Arduino UNO in this project.

This is gonna be controlled through an Android phone via bluetooth. I connected an HC-06 bluetooth module for this purpose.

I used an L9110s motor driver to drive the motors.
All the hardware set properly, now I come across the main hiccup - programming.

While I managed to get a proper code and an Android app to control the 4 Servos, I couldn't write a code that can control the Servos and the DC geared motors simultaneously.

Can anyone find me a proper code and an Android app for this purpose? It's the biggest challenge yet and it's great if someone can help.
Also would anyone recommend a good power source? I am currently using a 2100mAh PowerBank for the Arduino and a 6V Battery pack for the DC motors. Will the Servos burn out? Will the circuits be damaged?

Thank You!

#### PaulS

#1
##### Jan 12, 2017, 02:42 pm
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I couldn't write a code that can control the Servos and the DC geared motors simultaneously.
Why not? What did the code you actually wrote do that you didn't want it to do? What did it not do that you wanted it to do? Where IS it?

Quote
Can anyone find me a proper code and an Android app for this purpose?
I'm not even going to think about looking for code that does something so nebulous.

Quote
Will the Servos burn out?
If there are 6V servos, no.

Quote
Will the circuits be damaged?
Do you understand what 2100mAh means? It says nothing about how much current your servos and motors draw. It simply says that it can supply some amount of current for some period of time. If you pull that current at the rate of 0.001A/h, the power supply will last 2100 hours. If you pull that current at the rate of 420000 A/h, the battery will be dead in less time.

One amount of current will be fine for your circuits. The other, no so much.

#### movinperera

#2
##### Jan 12, 2017, 04:17 pm
Can you tell me how to write the code that can make the 3 micro servos and 1 standard servo work as well as the 2 Geared motors? Thanks

#### PaulS

#3
##### Jan 12, 2017, 04:21 pm
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Can you tell me how to write the code that can make the 3 micro servos and 1 standard servo work as well as the 2 Geared motors?
That is still not an implementable set of requirements. The servos are controlled, quite easily, using the Servo library. The geared motors should be connected to a motor driver which has an enable pin and a speed pin for each motor. The enable pin really should be called a forward/reverse pin, because that it what it controls. The speed pin is fairly obvious.

Show the code that you have now, and explain what it does that you don't want, and what it doesn't do that you want.

#### movinperera

#4
##### Jan 23, 2017, 01:12 am
I built a robotic claw actuated by a 9g micro servo and a HC-SR04 Ultrasonic sensor is mounted on it aimed at the middle of the two 'fingers'.
I want the claw to open when an object comes 15cm or lesser length towards the gripper, and I want it to close when the object comes 13cm or lesser length towards the gripper.
The micro servo operates in 90 angles.
Can anyone plz give me a code capable of doing the above task?

Thnx

#### manor_royal

#5
##### Jan 23, 2017, 05:07 amLast Edit: Jan 23, 2017, 09:04 am by manor_royal
I want the claw to open when an object comes 15cm or lesser length towards the gripper, and I want it to close when the object comes 13cm or lesser length towards the gripper.
The micro servo operates in 90 angles.
Can anyone plz give me a code capable of doing the above task?
You go first: I'm sure you'll get advice on code that isn't working properly if:

• You post the code
• You post any error messages if it's a compile problem
• You describe what the code should do
• You describe what it is / is not doing
• You post a schematic of the circuit
• You give details (or links to details) of the hardware, including power

Have you:

• Got the gripper working with say the servo sweep code to at least open and close?
• Got the distance sensor say serial printing the distance?

Do you:
• Know how to use an "if"

If this was a Civil Engineering forum would there be posts like "I need to build a bridge. Someone send me drawings."

#### anbukumar73

#6
##### Jan 23, 2017, 08:52 am
Even I am looking for similar code to operate a robotic arm with 5 servos

#### manor_royal

#7
##### Jan 23, 2017, 09:44 am
Even I am looking for similar code to operate a robotic arm with 5 servos
Well you should also either try to write it yourself, or at least describe your hardware config and what the heck the sketch is supposed to do to "operate" the arm.

If this was a Civil Engineering forum would there be posts like "I need to build a bridge. Someone send me drawings."

#### movinperera

#8
##### Jan 29, 2017, 06:12 pm
Oh come on guys i need a code to control 2 dc geared motors with the L9110 h bridge module via the HC -06 bluetooth module.
When motor1 and motor 2 are on, car goes foward
When motor1 and motor2 are on the otherway, car goes reverse
When motor1 is on & motor2 is off, car goes right
When motor1is off & motor2 is on, car goes left.

All of this is done via bluetooth serial communication, and as I'm still new into programming i need a kind of skeleton to work on this project. Pls use an example schematic to answer this so i can later modify it to suit my needs.
Thanks

#### jwloach

#9
##### Jan 31, 2017, 02:19 am
To get started, try the makeblock stuff.

http://www.makeblock.com/en

It uses an Arduino Duo, with fixtures and libraries to add just about any kind of sensor or motor you can think of. You'll learn it all really fast. Reasonably priced too. Program it in C or Scratch.

It's a bit of a cheat, though, because the finicky wiring is all done for you. But, heck, you hit the ground running.

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