Hi everyone.
I posted a question in regards to reducing the speed of my two 12v motors on the forum last week and I have been pointed in the direction of using motor controllers, and after a response I got from Rich, I found out that it is possible to use two controllers through one EZ-B, so I have ordered two 2.5 amp motor controllers from EZ Robots.
The reason why I need to use two is because the drivetrain for my robot build runs off a 12v battery and has two 12v drive motors that draw about 0.50 amps while running, but can hit about 1.4 amps peak for a split second, so using both channels on the 2.5 amp motor controller with a max peak limit of 3 amps per channel, that takes care of the drive motors.
The drive train also has one 12v steering motor that runs at 0.24 amps with a peak of about 1.3 to 1.4 amps, so apart from needing a third channel I wanted to leave a safety margin, that's why I will require a second motor controller (only using one channel) connected to the EZ-B v4, which I wasn't sure could be done. But as I mentioned above, Rich told me that although it is not done often, it can be done but the second controller would require scripting. So what I would like to ask is...
1.) Has anybody else done this with a similar set up to my example?
2.) Are there any examples of this in action? e.g, controlled via on screen sliders ect.
3.) I'm assuming that I will have to run 2 pairs of power leads from my 12v battery and connect to each L298. Is this correct?
4.) How would to L298's be wired up to a single EZ-B with speed control? I know Rich has a tutorial but I would also like to hear from other members who have done this. synthiam.com/Community/Questions/4096
5.) And finally, and this is the main point I am unclear of, one L298 can be controlled through the EZ-B via on screen sliders, smartphone or Wii remote accelerometer movement, voice control ect ect. But I have read that the EZ software will only have these controls for one L298, so how will I be able to control the second L298 for the steering, say for example if I wanted to use it in a "radio controlled" scenario, with both the drive motor control slider and the steering motor slider on one computer/touch screen?
I am waiting for my first batch of EZ goodies to arrive sometime this month, so I am new to all this and only going by what I have read and seen online so far, so any help and/or advice any of you kind people can offer would be gratefully received. There is not that much mentioned about using 2 controllers with one EZ-B on the forum so hopefully any answers or advice given will go towards helping others too. Rich has already offered me help in regards to scripting a second controller which I surly will take him up on, but it this "how will my finished robot physically be controlled Via an iPhone of tablet PC once its scripted" thing I'm scratching my head over.
Thanks everyone.
Steve 
The two L298's have been ordered and should be winging their way to me soon. I'll post an update when they arrive and when I have them installed. Thanks for the advice everyone.
One thing, how do I close the question and say "Congratulations" to a member for answering the question? There wasn't a link in the question update emails I received, and I wanted to close this by thanking Rich.
Steve
Steve, no need to ID the contributor that helped the most since you did not start the thread as a question needing help.
Ok thanks for that Doc. I'll make a note of that for next time.
Cheers,
Steve.
@Rich.
Now my goodies have arrived I am starting back on my build, and one of the first things I will be doing will be to connect the motor controllers. I have read through your detailed post again, which once again I really appreciate you doing, and will follow the info you supplied, and if I get stuck I will give you a shout.
But, I do have an additional question for yourself or anyone else in regards to wiring up, specifically "power". The two drive motors (going to L298 number one) and the steering motor (going to L298 number 2) are all 12 volt and have their dedicated 12v battery. The EZ-B will be running off a 7.4v LiPo for EZ-B power, servos, sensors ect. So my question. How do I wire this set up correctly? I have a rough idea, but apart from "plug 7.4 LiPo in to EZ-B", I am a little unsure and want to make sure I get it right.
Cheers, Steve.
Steve, I am going to let Rich answer.
I use three h-bridges in my project garden-bot.
He runs great. I HAD it wired for v3 and now wired v4.
Each was a different wiring. Motors ran off 7.4 power supply. V3 controller off different power source, and supplied power for h-bridges. I used two pmw controls for left and right power control to motors. So I could make him go in circles or tight turns.
It is similar to what you are doing.
V4 wiring is different.
But still used the same ARC project did not add or remove any controls.
I will later in the day make it public in the cloud if you wish look at the project.
J
Thanks for the reply jdebay. I've looked through Rich's tutorial and DJ's video and I'm almost there. I just need to get the power wiring sorted as I mentioned in post #13, and a little confused to "common ground". confused
(-- EDIT --)
Forget post #13. I've just realise that my questions had already been answered in this thread. Sorry about that. Crazy week. eyeroll
One thing. Could someone confirm for me, where do I wire up the common ground between the EZ-B4 and L298. Is it...
from L298 "ground" to the barrel jack "ground" that plugs in to the V4,
or L298 "ground" to any "ground" pin on the digital ports? Thanks.
@Rich.
I need to take you up on your offer for a little help if something didn't make sense. (Or to anyone else who can help. Okay. So I'm in the process of wiring up my two L298's but I've hit a snag. I have been following Your advice and tutorial, but the L298's I have are a little different to what your and other pictures I have seen in other threads. As oppose to 6 pins I have seen, I only have 4.
Which is the correct way to connect the L298 to the EZB4 for left/right motors, and to have combined speed for both motors, not independent?
Thanks. confused
Don't worry about the last post. I worked it out. I do have another question however. I have got the 2 H-bridges working together, but the issue I have is with steering. I have used an expletive script so I have got the steering to turn left and right. How do I get the steering to center? I just can't figure it out.
Cheers.