Arduino Forum

Using Arduino => General Electronics => Topic started by: rshnk90 on May 20, 2016, 08:58 pm

Title: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 20, 2016, 08:58 pm

Hi there,

I'm going to build bluetooth powered device that deals with motors. Not a single motor, But 3 Motors in diff volts.


1.) 12v DC gear motor 2RPM

2.) 6v DC gear motor 30RPM

3.) 6v DC gear motor 6RPM

Total: 3 Motors.


I'm thinking... to use Arduino UNO or Pro-mini to control these motors for directions and speed.


So, Let me jump straight to the question...

Question #1: -

What motor shield is best to power the above motors ? Is there a single motor-shield or do I need to use multiple ? I need a shield that is possible for the arduino to control the speed and direction of these 3 motors.

Question #2: -

I know, Powering these motors are not possible by Arduino. So, What volt of battery should I buy to power the following list of items below...

1.) 1 x 12v DC motor
2.) 2 x 6v DC motors
3.) Arduino UNO or Pro-mini
4.) HC-05 Bluetooth Module


I'm not really a big fan of using multiple power supplies.  So, if there a solution to use single power supply to power all these what is best ? can you link me ? Or if there is no way other than using multiple power supply. What would be your best suggestion ?

I'm investing some serious money onto this project, Kindly help me with some serious thoughts though.

I'll be so grateful and appreciate your help throughout.

looking forward. thanks.



Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 12:36 am
Expecting some inputs... anyone ?
Title: How much volt battery I need ?
Post by: rshnk90 on May 21, 2016, 12:53 am

Hi there,

I'm investing to build a project at home with some arduino knowledge, But im not sure about the batteries. What volt battery should I buy to power the following list of items below...


1.) 12v DC gear motor 2RPM - not sure

2.) 6v DC gear motor 30RPM  - 120ma

3.) 6v DC gear motor 30RPM  - 120ma

4.) Arduino UNO or Promini

5.) HC-05 Bluetooth Module.


Does 11.1v lipo battery be good to power all the above ? I'm looking for a single power source to do all the work rather than separate sources. please advice.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: couka on May 21, 2016, 01:12 am
For controlling speed and direction, you need an h-bridge per motor. Which one is suitable depends on the current.

For the voltage supply I would either use a 12V supply + step-down converter to 6V or a 6V supply + step-up to 12V.

lg, couka
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 02:02 am
Thanks Couka,

The H-Bridge Dual is what I'm having right now. It has slots to connect up to 2 motors. what about the 3rd motor ? Do I need another shield and use it ?


Quote
voltage supply I would either use a 12V supply + step-down converter to 6V or a 6V supply + step-up to 12V.
Sorry, excuse me. I don't get that part...

Do you mean.. to use 12v supply and use a step-down converter to 6v only to power arduino and 6v motors ? While the other motoer and H-Bridge connects to raw 12v supply ?
Title: Re: How much volt battery I need ?
Post by: Wawa on May 21, 2016, 02:07 am
No motor drivers?
They (the wrong ones) might also drop some voltage.
A 3C LiPo seems good, if you have a dedicated balance charger for that.
If weight/size is not important, an easier to charge small lead/acid battery might do.
You can drop the voltage to 6volt almost lossless with a stepdown/buck converter.
The HC-05 module on a carrier board has it's own onboard 5v to 3.3v regulator.
Post links/datasheets and a description of your project if you want better advice.
Leo..
Title: Re: How much volt battery I need ?
Post by: rshnk90 on May 21, 2016, 03:15 am
Thanks wawa!

Sorry, I forgot to mention the Dual H-bridge motor-shield which I will be using to control these motors via arduino. I don't have a datasheet at the moment, But soon will be making one.

I'm just shopping the parts at the moment...

Do you think it is best to use a 6V DC motor of same 2RPM ? I just found that it is available at store.
So making all 3 motors at 6V. Do you think the volt will affect the torque ? Im confused here.

I'm making a RC controlled kinda truck with some additional functions that uses additional motor.

Title: Re: How much volt battery I need ?
Post by: Wawa on May 21, 2016, 03:27 am
All motors of the same voltage seems less complicated.
A motor of the same size/model should have the same torque.
Half the voltage is twice the current (same power).
Leo..
Title: Re: How much volt battery I need ?
Post by: rshnk90 on May 21, 2016, 03:38 am
Quote
Half the voltage is twice the current (same power).
Does this affect the H-Bridge Driver ? Cause I read somewhere that it has a certain max amp power.
Since I'm running 3 motors would that be a problem ?

Do you think.. switching all motors to 12V of same size/model with less current is best or 6V with more current is ?

If 12V of same size/model is advisable, then powering up these 3 motors with 11.1v Lippo Battery is good ?

PS: I will be using a step-down buck to 6V for the arduino from this battery supply as well.

Sorry for too many questions, Is this good to go ?
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: Coding Badly on May 21, 2016, 04:52 am

@rshnk90, do not cross-post.  Threads merged.

Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: couka on May 21, 2016, 09:31 am
Sorry for too many questions, Is this good to go ?
Since you didn't tell us what the motors should do, it's hard to say if a solution is good enough.

At 11.1v the motors will turn a bit slower and have not at much torque as at 12v. But if you power them directly from a battery, you can't avoid changes in the voltage, anyway.

So more information about your project -> better suggestions.

lg, couka
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 11:12 am
I haven't seen any replies addressing the fact that the OP plans to power the UNO (or Pro-Mini) from the same battery powering all the motors. I do see an issue there with the motor noise generated and it's effect on the uP. Motor spikes on the UNO regulator input could result in errors or resets unless you add some substantial filter caps (470 uF or greater).
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 12:23 pm
Update: Since my motor-shield driver has only 2 connections to connect a maximum of 2 motors. Im going to use only 2 Motors. So, I guess I will be going with 12V each for both the motors.

12V 2RPM DC Motor  +  12V 300RPM DC Motor
Both have extended gear box for high torque.



Quote
Since you didn't tell us what the motors should do, it's hard to say if a solution is good enough.
Thank you for taking the time to reply, Couka. Appreciate it.

As mentioned earlier in the above post, I'm building a RC truck with some functions that carrys objects and run forward and turns. Similar to a crane. For these, I planned to use 2 different motors. 2RPM for high torque to lift and other 1 for movements.


When I searched online for 12V lipo..that time i was only able to get 11.1v and the seller told me at peak charge it will supply 12v.

But later I found a 12v power supply here :
http://www.ebay.com/itm/High-Power-12V-Rechargeable-Li-po-Battery-for-CCTV-Cam-6800mAh-Useful-/301776949619?hash=item46434ed173:g:OisAAOSw14xWKcWn


Will that be suitable ?


Quote
I haven't seen any replies addressing the fact that the OP plans to power the UNO (or Pro-Mini) from the same battery powering all the motors. I do see an issue there with the motor noise generated and it's effect on the uP. Motor spikes on the UNO regulator input could result in errors or resets unless you add some substantial filter caps (470 uF or greater).
Thanks for taking the time to reply, Raschemmel. Appreciate it.

The motors will be driven by a dual H-Bridge motor-shield via arduino and
I planned to use a step-down buck that converts the 12v to 6v to powerup the uno or pro-mini. But I didn't know the spikes will affect the board. So, Do I need to add a 470 or 570uf ? Please advice.




Updated Part List:

1.) 12V DC Motor x 2 (http://www.ebay.com/itm/12V-DC-300-RPM-High-Torque-Gear-Box-Electric-Motor-Hot-/150530611989?hash=item230c52db15:g:jLgAAMXQskFRHvqm)

2.) H-Bridge Motor Shield (http://www.ebay.com/itm/L298N-Dual-H-Bridge-DC-Stepper-Motor-Drive-Controll-Board-Shield-for-arduino-/262312166206?hash=item3d1306033e:g:H-AAAOSwll1W06d3)
 
3.) 12V Lipo battery (http://www.ebay.com/itm/High-Power-12V-Rechargeable-Li-po-Battery-for-CCTV-Cam-6800mAh-Useful-/301776949619?hash=item46434ed173:g:OisAAOSw14xWKcWn)

4.) 12V to 6V Step-Down Buck for powering arduino..etc.  (http://www.ebay.com/itm/Waterproof-DC-DC-Converter-12V-Step-down-to-6V-3A-15W-Power-Supply-Module-/321024518442?hash=item4abe8d692a:g:uiEAAMXQ56ZSBQtQ)

5.) Arduino UNO or Pro-mini ( obviously )

6.) HC-05 Bluetooth Module

Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 12:47 pm
Don't know.
Wait and see what happens.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 12:52 pm
Quote
Don't know.
Wait and see what happens.
Sorry mate, I'm no way have any experience in this. That's why I'm seeking some advices from experts like you. Hope you could lead me to a better path with this project.


I have updated my post above with links to the parts that i will be using.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: couka on May 21, 2016, 01:29 pm

The motors will be driven by a dual H-Bridge motor-shield via arduino and
I planned to use a step-down buck that converts the 12v to 6v to powerup the uno or pro-mini. But I didn't know the spikes will affect the board. So, Do I need to add a 470 or 570uf ? Please advice.
[/quote]

There should be caps of a few 100µF, your arduino is probably fine, if the motors are connected to the 12V side.

The battery you posted probably works, but note that the capacity is actually only about 2200-2300mAh (and the usable capacity is even lower, since it seems to cut-off at 3.6V) and the charger... well I would not let it charge unsupervised. Really.


lg, couka
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 02:38 pm
Quote
There should be caps of a few 100µF
Can you let me know where this should be exactly placed, to the motor points itself or arduino pins ?


As for the battery, You mean 2200-2300mah is good enough to run all the parts and no need for 6800mah ?

If no, do you have any other suggestions for the battery ( maybe a link to the product itself would be nice to have a look )


Thanks Couka!!
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 04:04 pm
I said "wait and see" because there is no way to know in advance if the Buck converter will filter the spikes until you actually try it. For the samereason, no one can know how many uF to use until you try it. 100 uF may not be enough. As far as WHERE to put the caps ?
Thar's simple, on the input and output of Buck converter.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 09:24 pm
Thanks Raschemmel, I will try starting with 100-200uf and see how it goes.

By the way, Im still confused at what power source would be better in terms of size and weight. I'm trying to keep it small as much as possible with sacrificing little weight ( since im using high-torque motor )

So, 3.7v 2600mAH x 4 (cells) = 14.8v / 10.4AH  Is this a good choice to power the 2 x 12V motors + all other components ? cause I'm worried.. about 14.8v if it would damage the motors.

and instead of 4, If I use 2 cells.. it is 7.4v which is lower than the required current. but use a boost convertor for 12v ?

Any ideas and suggestions for this ?
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 09:41 pm
FYI, since you seem to be new to Lipos,
Quote
Most LiPo/Lion cells are 3.7V nominal (4.2V max and 3.2V min), so a 4S pack should go up to 4*4.2V = 16.8V at full charge and go down to no less than 4*3.2V = 12.8V at full discharge.Oct 14, 2012
Quote
Is this a good choice to power the 2 x 12V motors + all other components ? cause I'm worried.. about 14.8v if it would damage the motors.
NO.
Use 3S (12.54 V at full charge, can be as low as 3*3.2V = 10.7V).
Not a good idea to overvolt the motors. If you were using some kind of closed loop feedback you could regulate the voltage using the PWM duty cycle. I haven't seen any vendors link for you motor shield so I can't comment on that. In fact , I haven't seen anything from you on how you actually plan to control the motors. No mosfet part numbers , no code, nothing. It is way to early to talk about controlling the voltage of a system that hasn't even been designed yet. As far as I can tell, you have the cart before the horse. Where I work, they design the system, have engineering design reviews,
finalize the design, then order parts. I don't know where you learned electronics but they must do things backwards there. Sorry if that doesn't sound too complimentary but I call it as I see it.
Post a schematic of your system and then we'll talk. Here on the forum , we do things the professional way. You may be a hobbyist, but we are electronics professionals, not hobbyists. We start with a feasability study or a preliminary design and refine it from there. The schematic is introduced early on, if only in a block diagram and then a real schematic. The code should start with an algorithm, and then progress to actual code. We don't just throw stuff together and turn on the power. That's what hobbyists  do, which explains why they wind up here asking for help.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 09:52 pm
FYI, since you seem to be new to Lipos,
True, I'm new to this and thanks for clarifying the volt. I'm still concerned about the space, Can I use 2 x 4.2v (aka 3.7v) cells and use a boost converter for 12v ?

Is that advisable to do ?
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 09:59 pm
Quote
Can I use 2 x 4.2v (aka 3.7v) cells and use a boost converter for 12v ?

Is that advisable to do ? 
Based on your specs of 120 mA/per motor, something like this (http://www.getfpv.com/12v-step-up-voltage-regulator.html?utm_source=google_shopping&m=simple&gclid=Cj0KEQjwjoC6BRDXuvnw4Ym2y8MBEiQACA-jWQPFM44LC8_V9eKKEwHvkDiAy1DzSNte0PuQdCourK4aAuJ48P8HAQ) could work.

You need to remember that you will have to do system level testing to fine tune the filter cap values.
You should not be shopping for motors without shopping for motor driving mosfets or a motor shield at the same time. One should be chosen to match the other.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 10:33 pm
I tried putting it to cart and they charge more for the shipping than the product itself. $10.78 ( excluding 3.99 ) outside US.

So, I tried to find the same on eBay, but I came up with something similar like this

http://www.ebay.com/itm/5pcs-2A-DC-DC-2V-24V-Step-up-boost-Power-supply-Converter-Module-/201577598458?hash=item2eeef60dfa:g:scoAAOSwf-VWXV4p (http://www.ebay.com/itm/5pcs-2A-DC-DC-2V-24V-Step-up-boost-Power-supply-Converter-Module-/201577598458?hash=item2eeef60dfa:g:scoAAOSwf-VWXV4p)

or

http://www.ebay.com/itm/2pcs-DC-DC-Adjustable-Step-up-Power-Converter-Module-XL6009-M17-/301723389663? (http://www.ebay.com/itm/2pcs-DC-DC-Adjustable-Step-up-Power-Converter-Module-XL6009-M17-/301723389663?)

Does that work too ?
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 11:28 pm
Looks like it would work .
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 11:34 pm
Looks like it would work if the input voltage is < 8 V.
I guess the second link wont fit ? Since my volt will be 4.2 x 2 = 8.4V

What about the 1st link, it doesn't say anything like that

Maximum output current: 2A
Input Voltage: 2V-24V
Maximum output Voltage: greater than 28V

So think that might work ?
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 11:39 pm
That's incorrect.

Input voltage is 5V < 8 V  so it is fine.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: rshnk90 on May 21, 2016, 11:50 pm
That's incorrect.

Input voltage is 5V < 8 V  so it is fine.
But that is  4.2volt each cell. If I use 2 cell it's 8.4 right ? correct me again please.
Title: Re: Need Advice on MotorShield - Shoot your suggestions!!!!
Post by: raschemmel on May 21, 2016, 11:53 pm
The boost converter input voltage range is 5V dc to 32 Vdc.
The battery voltage falls in that range. There is nothing else to discuss.