Society of Robots - Robot Forum

General Misc => Misc => Topic started by: ranbelt67 on November 29, 2012, 10:49:58 PM

Title: I have a really quick question
Post by: ranbelt67 on November 29, 2012, 10:49:58 PM
I've decided to tackle the $50 robot project but I will be using the tamiya track and wheelset along with the Tamiya twin-motor gearbox and would like to know if there are any parts I should and should not buy or if there is anything different I need to do.
Title: Re: I have a really quick question
Post by: newInRobotics on November 30, 2012, 03:25:40 AM
If You want to use motors instead of servos, then You need to get/build an H-bridge (1 per motor), also, some code changes will also be required.
Title: Re: I have a really quick question
Post by: ranbelt67 on November 30, 2012, 10:45:18 AM
Ok would you happen to have the model # for the H-bridge and if you could include the code changes as well that would be great. Thanks for the help!
Title: Re: I have a really quick question
Post by: ranbelt67 on November 30, 2012, 11:50:52 PM
If You want to use motors instead of servos, then You need to get/build an H-bridge (1 per motor), also, some code changes will also be required.

Ok would you happen to have the model # for the H-bridge and if you could include the code changes as well that would be great. Thanks for the help!
Title: Re: I have a really quick question
Post by: newInRobotics on December 01, 2012, 05:01:44 PM
I haven't got either of these, but Googling one and the other will bring plenty results  :)

The thing is, if You choose not to follow tutorial to letter, that means that You have to have enough knowledge on how to achieve goal with changes in mind. For this change Google AVR Timer Tutorial (http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=50106), as it's the way motor is driven. Also, if You search this forum for H-bridge, You'd most likely find How to drive pMOS and nMOS H-bridge? (http://www.societyofrobots.com/robotforum/index.php?topic=14760.msg107517#msg107517) thread.

Good luck :)
Title: Re: I have a really quick question
Post by: ranbelt67 on December 01, 2012, 10:26:09 PM
I haven't got either of these, but Googling one and the other will bring plenty results  :)

The thing is, if You choose not to follow tutorial to letter, that means that You have to have enough knowledge on how to achieve goal with changes in mind. For this change Google AVR Timer Tutorial (http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=50106), as it's the way motor is driven. Also, if You search this forum for H-bridge, You'd most likely find How to drive pMOS and nMOS H-bridge? (http://www.societyofrobots.com/robotforum/index.php?topic=14760.msg107517#msg107517) thread.

Good luck :)

What would the H-bridge plug into? Sorry, just starting out in the robot stuff. Trying to read as much info as possible lol  :)
Title: Re: I have a really quick question
Post by: waltr on December 01, 2012, 11:33:19 PM
Read the articles and tutorials in the "Robot Tutorials (click on this in the top, right corner of this screen.

An H-bridge goes between the controller (typically a micro-controller or processor) and a DC brushed motor.
Title: Re: I have a really quick question
Post by: ranbelt67 on December 02, 2012, 05:42:28 PM
Hey in the tutorial it doesn't say anything about what kind of wire to use. Does anyone know what gauge to use?
Title: Re: I have a really quick question
Post by: jwatte on December 02, 2012, 10:23:55 PM
That depends on how high current you want to draw, and how long a cable run you want to run.

I find that 24 gauge twisted/stranded wire can easily supply a 5A motor over short distances. 16 gauge twisted/stranded wire is still very flexible, and is good for things like power busses and main battery connections.

There's a pretty standard function for "safe" currents for "permanent" installations at "industrial" spec, which you can find (for example) here: http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity (http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity)
Note that my recommendations push harder than this table recommends, but for battery powered hobby robots with short cable runs (< 1 ft each, say) that's not likely to be any kind of problem.
Title: Re: I have a really quick question
Post by: ranbelt67 on December 02, 2012, 11:51:06 PM
Thanks for the help guys BUT I have one more question (last one I promise!) I'm going to be using a solderless breadboard, is there anything different i need to do in making the circuit? Or are there some kind of instructions I can follow? Thank you all again for the help!!! :) 
Title: Re: I have a really quick question
Post by: jwatte on December 04, 2012, 12:24:22 PM
Just make sure the connections are tight, and if you use components with long leads, that the leads don't touch each other to make unintended connections.