
robohobo
hello all,
im in the process of building my first ez robot and ive realized how much i truly have to learn at once. anyway when i ordered my rover 5 chassis (4 motor w/ encoders model) i opted to go with the dagu 4ch motor driver since it supported the encoders. i now realize that as a beginner wanting to jump in head first this wasnt the best idea. im fairly certain ive figured out how to correctly connect the driver to ez-b and both to my 6v sla power source, but if anyone has a diagram of how to do this properly i would feel more comfortable. my major problem is scripting a custom control panel to drive this thing. i have no clue what im doing and a push in the right direction would be greatly appreciated.
maybe DJ will add this motor controller in a future update? as i understand it ez-robot works very closely with dagu and carrys the rover 5 in store so it seems likely. ill cross my fingers.
If you can diagram it as a schematic just to ensure everything is as thought that would be great. www.CircuitLab.com is simple to use and free if you don't have any other software or aren't familier with any other. Or ExpressPCB is a free schematic application.
I'm eager to get this set up and working for you. It'll ultimately decide if I go for this controller or the L298 (since this one is out of stock where I was going to get it hence not having it yet).
PWM(D14,1)
sleep(75)
PWM(D14,0)
set(d14,off)
D14 is the PWM output on my EZ-B that drives the Motor Speed on the DAGU controller.
I have a FWD Script, LEFT Script, Right Script, BACK Script, and a STOP Script.
The website prices are lower, but I think the shipping is higher. I guess it probably balances out.
@RoboHobo great news
To stop, it looks like you will need to use @RobertL184's script.
So, did it work? Well, yes. Ish.
Problem 1, the plugs on the Dagu chassis' motors are backwards. They are one-way only plugs, so connect only one way to the board. But when plugged in thusly, the red wire is on the gnd pin, not the red one. Without un-crimping/re-crimping the plugs, they will always be backwards. Thankfully, as I udnerstand, that doesn't matter really. It just means everything backwards.
Anywho, problem 2...
With all 4 motors hooked up, the pairs need their directions reversed relative to each other, otherwise the script fails.
If we say for arguments sake, the motors are labelled thusly;
^Front^
1-----3
| |
| |
| |
2-----4
(Warning, weird pseudo-code coming up!)
In this case, motor 1 has to be set Dir(0) with motor 2 Dir(1), otherwise they both turn opposite directions, resulting in a whole lot of unhappy motor-fairies. Could this be a result of the weird plugs, I don't know. The same goes for 3 and 4. As a result, the custom Movement Panel doesn't work (It sets all to off or on). Obviously, this fix is quick and simple.
Problem 3... For some reason, when using the Stop button on the custom movement panel, none of the motors stop turning. In addition, if you slide quickly from ON to OFF on a PWM slider, the motor doesn't stop. Only when going gradually from top to bottom does it shut off. It's almost like it needs to hit 1% then 0% to turn it off. I don't know if this is a Dagu issue or an EZB issue.
Anywho, I'm exhausted from work, so I'm going to fiddle again tomorrow.
Hope some of this makes sense!
- Bill.
I so should've read the rest of the forum post before putting up my post. I see from Robert's script that he already addressed the stopping issue.
Makes me wonder, why is this the case? Is it dagu or ezb based, and would kicking it help?
Unhooked everything, plugged in Logic power, then motor power and a second coming of Puff, some more magic smoke. :/
Bummer.
- Bill.
one question though, when i was putting things back together more permanatly i forgot to plug the +5v and gnd from the ez-b to power the logic. It was unplugged the entire time i was scripting the rest of the custom Movement Panel and through all the "testing" i did once i had it right. what exactly is this powering?
Great news Robohobo. I have no idea what it powers though. It may be +5V to supply the microcontroller as I have recently learnt some other controllers have... but I'm guessing.
Thankfully, the dagu boards aren't expensive, so another one is already on it's way. With a nothing-before-10am ban on it lol
Any idea on the common ground thing btw?