Robot Project , utilizing different resources

Thread Starter

Zarkopafilis

Joined Nov 17, 2013
3
Hello everybody , I am a C++/Assembly developer . Me and another guy near my house decided to start a project. We will make a robot and program it to do various stuff. We have already messed around wiht arduino but what it can do it very limited. Due to the fact that we cant find/build a custom PCB to control something big , we will stick with arduino and patents (e.g. cutting usb cables and connecting it with leds etc.)
I have a great variety of cables and tools. The fact that concerns me is voltage and amps. I cant remember what I was taught in high-school so I decided to ask the community here! After we end up having the code ready and be able to control everything , we will need to mess around with current to do misc stuff.
We will be testing the patents with batteries at first and then connect it to the main robot that will make everything work -hopefully!-
So , my question(s) are : What should we use?(arduino or ...?)
Please provide me with enough information.
If we end up using something like arduino , which would be the best option to retreive power from? USB , Ethernet(I dont even know if we can reverse what PoE does...) or ...?
What I think we will be using:
-Leds
-Motors
-Other stuff that make it look cool?xD
-Wifi antenna (Its something that we want to do when the project is finished, control it from a pc at first and then with a portable device , I know the whole idea is big but if we get this together , It would be really cool!)
Thanks it advance
~Zarkopafilis , Victor Ks (The team!)
 

wayneh

Joined Sep 9, 2010
17,498
We will be testing the patents with batteries at first...
Huh? A patent is a legal document filed with the patent office. Not sure how you test it with a battery. :confused:

If there is a question in your post I think it is: How do I control power components (lights, motors) with data-level (low current) signals? Is that right?

You need to learn about the MOSFET H-bridge. It's a standard tool to control motor direction and speed and is the go-to technology in robot motor control.

Other items that just need switching on and off (or dimming), like LEDs, can be controlled with a MOSFET switch. Dimming is accomplished with PWM control of a MOSFET switch.
 

Thread Starter

Zarkopafilis

Joined Nov 17, 2013
3
Nevermind about the patent and the testing. So , is there something better than an arduino or not? And what about power from the computer's ports?

I am not english or so , but I already have certificate of profeciency in english but I am facing difficulties with all these science-oriented words and stuff...

I already know about the MOSFET bridge and stuff. I am concerned more about doing something at least , and then proceeding to something big. We need to start building the project with perspective for more and more! Thanks in advance anyway. And something about dimming , I have heard something abouts Ωs but I think I should use amps ... is that right? The only things I got taught at school is Resistace , Volts and Amps... Thanks again!
 

tshuck

Joined Oct 18, 2012
3,534
Nevermind about the patent and the testing. So , is there something better than an arduino or not? And what about power from the computer's ports?
Yes, there are better things, but better in what way? If you want an easy to use controller, use the Arduino. If you want a more professional grade controller, grab an ARM processor.

If you are making a robot, do you want to be tethered by a power cable? Batteries are the first choice for a mobile robot. To answer the question, no, the USB port can source a maximum of 0.5 Amps, and that's only after you've negotiated that from the USB host, otherwise, you've only got 100 mA to work with - not too useful for a robot...
 

wayneh

Joined Sep 9, 2010
17,498
I already know about the MOSFET bridge and stuff. I am concerned more about doing something at least , and then proceeding to something big.
That is the advantage of using MOSFET circuits. You can scale them up to very large amperages by using a MOSFET with the proper ratings, with little concern for the other control circuitry. (Almost NO concern, but you may need a proper MOSFET driver as the scale increases.)
 

Thread Starter

Zarkopafilis

Joined Nov 17, 2013
3
Yes, there are better things, but better in what way? If you want an easy to use controller, use the Arduino. If you want a more professional grade controller, grab an ARM processor.

If you are making a robot, do you want to be tethered by a power cable? Batteries are the first choice for a mobile robot. To answer the question, no, the USB port can source a maximum of 0.5 Amps, and that's only after you've negotiated that from the USB host, otherwise, you've only got 100 mA to work with - not too useful for a robot...
Better than they arduino in any way!(Even if it is harder , I want to do it!)

Well , I don't want it tethered. USB and stuff will be used for some other stuff. I have heard that with the apple drivers you can give up to 0.7-1 A... I dont know if it is the truth tough!
I was considering the idea of building a custom PCB , and it seems legit... Batteries , rechargable batteries! But how many/what type of them? I have 2 AAs (eneloop) and they are pretty old but mostly unused. How am I supposed to scale amps with the MOSFET? Also , I am not an overclocker and I want to know the whole power control of it. I mean , can I even overclock a motor?
 

Danm1

Joined Jul 19, 2010
69
You should start with something simple, just to make it a project you at least finish the first phase. If you already have Arduino then use it, if you are a student and you get to the point where you have exhausted the capabilites of Arduino with all the features you have added to your robot, then you have accomplished something to be proud of and have learned a lot and then can justify spending money on better hardware.
 

tshuck

Joined Oct 18, 2012
3,534
Again, like all things in engineering, there are tradeoffs. You need to specify in what way is it better. One person might say the Arduino is better because it is easier to use, while another might like the MSP430 due to its low power consumption.

The current outputs are USB spec, I doubt that what you heard is true.

2 AA batteries are not going to be enough for any robot beyond the capability of a bristlebot (none).
 
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