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.
The Current outputs (cur) can be connected to the ADC ports of the EZB to monitor the current. 1V = 1A with a maximum of 5V so they are fine to just connect direct to the EZ-B. Use ADC controls to monitor it or a script with GetADC() to check the port and act on a high current.
Direction pin is either a high or low for direction. So I assume connect to a dgital port and a Set Digital control or a Set() script command, on for forwards and off for reverse (or vice versa, it didn't say which yet).
PWM to a digital port and use PWM sliders or PWM() command to set the speed.
I haven't a clue when it comes to the encoders.
Of course, there may be an easier way of doing it, I'm just going from what I read in the manual.
I have been working on something truly awesome!
I had already abandoned the encoders because I'm simply not experienced enough, so this is great news. You and @Rich have made my day and resparked my building bug. Project post soon! Thanks Again!
But, to put it basically you just need to consider how it will move.
Forwards - SetDigital to either high or low (on or off) depending on which does which for all 4 motors. PWM to 100 for full speed.
Reverse - As above but SetDigital the other way.
Left - Left hand wheels to go in reverse at full speed, right hand wheels forwards at full speed.
Right - Left hand wheels forwards at full speed, right hand wheels in reverse at full speed.
You could turn left and right with a forwards ARC by just slowing the left or right wheels down. If the wheels on the left are slower than the ones on the right (and slower includes running the other way) the robot will turn in the direction of the slower wheels.
All signal wires should be ground when the EZB is disconnected from the PC and when PWM is off and Digital is off.
If you can list out which port you have connected where and which colour wire (or sig, vcc & ground if that's easier)
From what I understand of the manual you want...
D0 Sig to CH1 DIR
D0 Gnd to CH1 GND
D0 VCC not connected
D1 Sig to CH1 PWM
D1 Gnd to CH1 GND
D1 VCC not connected
D2 Sig to CH2 DIR
D2 Gnd to CH2 GND
D2 VCC not connected
D3 SIG to CH2 PWM
D3 Gnd to CH2 GND
D3 VCC not connected
D4 SIG to CH3 DIR
D4 Gnd to CH3 GND
D4 VCC not connected
D5 Sig to CH3 PWM
D5 Gnd to CH3 GND
D5 VCC not connected
D6 Sig to CH4 DIR
D6 Gnd to CH4 GND
D6 VCC not connected
D7 Sig to CH4 PWM
D7 Gnd to CH4 GND
D7 VCC not connected
Optional
ADC0 Sig to CH1 CUR
ADC0 Gnd to CH1 GND
ADC0 VCC not connected
ADC1 Sig to CH2 CUR
ADC1 Gnd to CH2 GND
ADC1 VCC not connected
ADC2 Sig to CH3 CUR
ADC2 Gnd to CH3 Gnd
ADC2 VCC not connected
ADC3 Sig to CH4 CUR
ADC3 Gnd to CH4 GND
ADC3 VCC not connected
D0 is direction of CH1
D1 is PWM/Speed for CH1
D2 is direction of CH2
D3 is PWM/Speed for CH2
D4 is direction of CH3
D5 is PWM/Speed for CH3
D6 is direction of CH4
D7 is PWM/Speed of CH4
ADC0 is current monitor CH1
ADC1 is current monitor CH2
ADC2 is current monitor CH3
ADC3 is current monitor CH4
At least that's how I interpret the manual
PWM(D1,90)
Set(d0,ON)
and one wheel began to spin, i then tried a few more scripts while it was still spinning (ie PWM(D1,0) and Set(D0,OFF) and a few other values in the pwm) and it just kept on spinning. Im sure im just missing something as these little tests were my first attempts at script. I gather this is your area of expertise. my robots almost rolling! so close I can taste it.
The 4 Set Digitals for direction, mapped to D0, D2, D4 & D6
The 4 PWM controls for speed, mapped to D1, D3, D5 & D7
Then click and slide in ARC to see what happens.
i.e. Set the PWM for one wheel to maximum (100) and see what happens, then click on the set digital for the same wheel and see if it reverses. Slide the PWM down towards 0 to see if it slows down. Click stop on the PWM to see if it stops.
I set up the controls based on the above ports. This is how I interpret the manual, it may not be right but looking logically it should.
I also took the liberty of setting up the Custom Movement Panel for forwards and reverse. I will leave you to attempt left and right (however ask if you get stuck). This is provided the above is correct of course.
@jstarne1 things come up man, I appreciate you trying.
I'm to excited, I'm gonna go work on my bot now!
Once direction control is known the custom Movement Panel can be altered for all wheels to move in the same direction. Depending on mounting positions of the motors will have an effect on which need to be moving forwards and which reverse, I just assumed all were the same way around.
When I get chance I'll have another look at the manual.
And an extract;
To me that says PWM to the PWM pins for speed control and off, and high/low (digital on/off) for direction control.
Ignore current for now (however I'm 99.9% sure a signal from an ADC connects to read the Current value from 0 to 5). And ignore the encoders.
I can't see that it's anything but what I've assumed and set up in the project file unless Set Digital doesn't work how I expect it to.
One other test could be to PWM 0 and PWM 100 to the direction pin to see if direction changes. However I was under the impression Digital on is the same as PWM100 and Digital off is the same as PWM0.
I've added a script to the project file called "Try Me". It uses PWM on all pins. It should, if it needs PWM rather than Set Digital, spin forwards for 5 seconds, stop for 5 seconds, spin in reverse for 5 seconds then a little bonus. Let me know how it works out. I refuse to be beaten
Have you tried the updated project file yet and run the "Try Me" script? You'll have to download it again from the cloud (or via ARC open from cloud) for the updated script (and bonus extras since I was bored at work). I've written it so it uses PWM for everything to see if that works.
I'll be sure to check the forums in the morning when I get up (or afternoon, it's been a while since I had the chance for a lie in), time difference means it's 1:20am here! I wont let this one beat me
I can't remember if I changed the movement panel, but the script will run through forward, reverse etc. once we figure out what needs to be done then we can tackle the Movement Panel :).
I then tried powering up the EZ-B first (which provides the +5v to the motor controller), and then connecting the power for the motors. still the same issues
I even tried powering up and connecting ez-b before connecting motor power. no change.
theres even a flux capacitor and it still doesnt work
its like we have plutonium, a nulear reactor, a flux capacitor, and a delorian, and we cant figure out how to steer it.
I found this, it's arduino but it had the code and wiring and I thought it might help somehow
I just found the board for pretty cheap, I'm tempted to grab one because I can't see what's wrong. Checking the Armadillo code for it shows pretty much the same as what I first thought (PWM for speed, Set on or off for direction).
Are you 100% sure the signal connections from the EZB to the board are right?
Makes no difference if I order it today, tomorrow, Sunday or Monday due to Easter but if we have hit a wall I'll get one on order (I need something for a rover project anyway, this is as good as anything else I guess)
i was wondering if its possible that it wont funtion properly without the cur pin connected. i had them connected but i took them off since @rich indicated them as optional and i ran out of jumpers just short of having jumpers for the grounds on the CUR channels.
what else could it possibly be? a faulty controller? not enough power? (everything connected to single 6v. 4.5ah SLA battery)
any thoughts are appreciated.
The CUR connections go to ADC ports so it shouldn't make a difference.
I've looked over the manual too many times now, it should be simple.
PWM is easy (did the speed control at the end of the script I wrote give speed control? It should have slowly ramped up to top speed)
Ground is easy
DIR says it's either on or off for forwards or reverse. A set digital gives that on or off.
All I can think of trying now is to confirm the set digital does what I assume it does...
You could try pulling the jumper from DIR while it's spinning forwards to see if that changes direction. No signal is a digital low, which according to the manual sends it the other direction.
You could also, at your own risk - I do not suggest this, I shouldn't even post it but I will because we are hitting a wall... You could remove the jumper from the DIR pin and connect DIR to ground to see if that spins it the other way.
Then wired two on the DIR pins together (i.e. CH 1 and 2 DIR inputs.) These are left side motors for me. I ran a ground for each of these as well.
Same thing with the other two DIR pins. (.i.e. CH 3 and 4 DIR inputs.) These are right side motors for me. I ran a ground for each of these as well.
Now you have your left and right levers controls of the tank.
A custom Movement Panel used to work nicely with this setup. There appears to be a bug in the latest code that prohibits the speed control of the custom Movement Panel from working correctly for me.
I initially controlled it with a Vertical servo (gas pedal) and two digital output controls (left and right tank levers). Push both levers forward (i.e. digital outputs on) and step on the gas (i.e. set the PWM to anything but 0). Away she goes.
To turn one lever forward (i.e. Digital output on) and the other lever backward (i.e. other Digital port off). To stop set PWM to 0 digital outputs won't matter. Easy to test operation. Enjoy.
I ignored the current outputs so far and I do not believe EZ B supports the encoders yet. I am hoping that will happen in a future release.
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?