Ez-robot And Zumo Robot

Question

Hy all,

I am Andrew from Romania , i have a ez-robot platform and a Zumo Robot from Polulu. The Zumo robot came with a H-bridge - DRV8835.

I dont know how to set it up. I know how to connect the motors, but i dont know how to set it up in ARC . Excuse my english. h-bridge from Polulu

Rich · Answer

There are a lot of details on the Pololu site I don't have time at the moment to describe it clearly but when I get home I will if nobody else chimes in with the answer

hhammoud · Answer

First step is to look at the tutorial Different board but should be same concept and last 45s shows ARC controls configuration that you can follow. H-Bridge

jstarne1 · Answer

Hiya , There are several variations of this little robot kit. You have a challenge here which is a very small size. Its 10cm x 10cm that's 4 inches. I will copy in a couple pics of what I believe you have too. Let me know if you have something different.

jstarne1 · Answer

PDF data sheet..

hhammoud · Answer

My understanding that he needs the steps of how to control it using ARC as he mentioned that he knows how to connect the motors.

jstarne1 · Answer

The phase pins are the same as signal pin in our h bridge tutorial. The enable is the same as enable in the tutorial , you can attach this to a pin with pwm control to adjust speed. To make a robot drive straight the pwm for motor A and motor B may be slightly different. Just adjust accordingly. The VCC pin is the power supply positive to the logic controller and VM is the voltage supply positive. These two can be the same wire. Ground of course is ground to battery on both sides. Lastly is the motor hookups. They are labeled Aout 1 which just means motor A output number 1. 1 is the red pos wire of motor a and Aout2 is black ground wire of motor A. Repeat for Bout1 and Bout2. leave mode empty, that's a special feature pin for stepper motors.

jstarne1 · Answer

leave VIN empty as the data sheet does not label or describe its function.

Rich · Answer

Yes that is my understanding too since he gave the link to the technical info. So, since I have the time to play now, let's give it a go  Nice and easy, it looks like it will work the same as the TB6612FNG Motor Controller Assuming D15, D16, D17 and D18 can be used. Signal from D15 to BIN2 Signal from D16 to BIN1 Signal from D17 to AIN2 Signal from D18 to AIN1 Ground from D15 to GND VCC from D15 to VCC Battery +ve to VIN Battery GND to GND Motor 1 +ve to AOUT1 Motor 1 -ve to AOUT2 Motor 2 +ve to BOUT1 Motor2 -ve to BOUT2 VMM left disconnected Mode left disconnected In ARC add a 4-wire H-Bridge Set the 4 ports to D15, D16, D17 and D18 - you will have to play around with which is which. I assume D18 first down to D15. You can Merge this file I've already set up, just merge the 4 wire h-bridge control panel. Please post back any feedback you have so I know if it worked or not.

Rich · Answer

@Josh, the VCC and VM shouldn't be the same wire. VMM is an output. Mode wants to be low, so grounded or disconnected. VIN is mentioned, 2-11 V motor power supply connection. Operation at low VIN voltages slightly reduces the maximum current output. VMM is a power supply to other components with reverse voltage protection. It's not needed in this case. I have edited my post to suit Actually I've started to doubt myself on this one... Will have another look over it in a second.

jstarne1 · Answer

The way I see it is if you don't have voltage to VMM its not going to do anything.

Rich · Answer

VMM has nothing connected. The datasheet states; Quote:VMM This pin gives access to the motor power supply after the reverse-voltage protection MOSFET (see the board schematic below). It can be used to supply reverse-protected power to other components in the system. It is generally intended as an output, but it can also be used to supply board power. Which is why I said it is an output. The motor gets it's power through VIN The logic gets it's power through VCC  This truth table shows how to supply the board with the GPIO/Digital highs and lows for operation. So basically, if set up as my earlier post, with D15 & D16 both high it will brake on motor b. If D15 is high it will move motor B forwards and if D16 is high it will move in reverse.

sereandrei · Answer

Hy all, Thanks for all the reply , i was amaze when i saw all the activity on this thread! First of all thanks Rich, now i can move the zumo robot with my ez-b. I have connected the ez-b to the zumo as following: D15 -> BIN2 D16 -> BIN1 D17 -> AIN2 D18 -> AIN1 Ground from D15 to GND VCC from D15 to VCC Now in the ARC i have chose a 4 wire HBridge Movement Panel and make the following settings : Left Trigger A -> D17 Left Trigger B -> D16 Right Trigger A -> D18 Right Trigger B -> D15 Now i have forward , left and right , but no reverse , i still need to play with the pin arrangement. Thanks all for the fast reply ! This is the robot

jstarne1 · Answer

Wow that little guy is fast! Are you going to sumo robot wrestle? Sorry Rich heck I guess I missed that in the PDF I read. But I'm glad you was able to figure it out quick.

sereandrei · Answer

Hy jstarne1, The motors on the zumo robot are 1:100 , they have speed but don`t have power. It is just fast . I will try to find out how to revers the little guy! Thanks again all for all the help !

Rich · Answer

Reverse should be high on both AIN2 and BIN2, however if you have forward, left & right working it makes me wonder if there's something strange that needs to happen too. When turning left & right does one wheel reverse and one go forward or does one only go forward? Reverse may need PWM on AIN1 and BIN1 or something... P.S. That's one quick little dude

sereandrei · Answer

So when i pres the FW - both of the motors are spinning in the same direction , for left - only the left motors spins , for the right - only the right motors spins. They are not turning in different directions when turning left or right. I saw the options on the H-bridge for the PWM signal but don`t know how to set it up in the EZ-B? Thanks all!

Rich · Answer

Looks like you need a custom movement panel, I'm on my phone right now bit when I get to a pc ill throw some instructions your way.

Rich · Answer

Right then, on a computer so it'll make it easier The best thing is to start a new project file for this, you can always merge it with your main project once you have sorted out the code needed. Assuming you kept the set up of D15 -> BIN2 D16 -> BIN1 D17 -> AIN2 D18 -> AIN1 In a blank project add the Custom Movement Panel (Control - Scripting) For Forward use the code
Set(D15, Off) Set(D16, On) Set(D17, Off) Set(D18, On)

For Reverse
Set(D15, On) PWM(D16,90) Set(D17, On) PWM(D18,90)

For Stop
Set(D15, Off) Set(D16, Off) Set(D17, Off) Set(D18, Off)

Try that first, if it works for reverse then I'll do left & right so they spin one side one way and the other side the other. If you are happy with how it is then you can use Left
Set(D15, Off) Set(D16, On) Set(D17, Off) Set(D18, Off)

and Right
Set(D15, Off) Set(D16, Off) Set(D17, Off) Set(D18, On)

Left & right might need adjusting depending on connections. Let me know what happens.

Rich · Answer

Just looking over the truthtable again, For forward of one motor you should have In1 High In2 Low For reverse it should be In1 Low In2 High Which is how the H-Bridge movement Panel works as far as I'm aware... If the above doesn't work for reverse, try
Set(D15, On) Set(D16, Off) Set(D17, On) Set(D18, Off)

Otherwise, you could add 2 Digital (Set Digital) controls, one for AIN1 and one for AIN2, see what happens with both off, one on one off, the other on the other off, and both on.

sereandrei · Answer

Thanks Rich , i will try running the script when i arrive home. Thanks for all the support now i finally understand how the ez-b works.

sereandrei · Answer

Hy again, On the custom movement panel i am not able to set multiple parameters like you said. For example for FW: i can only set one pin D17, on. How can i set multiple comands on one comand? Thanks !

Rich · Answer

There's an icon, looks like a pencil, on the right of the command line field, click on it and it opens the script editor.

sereandrei · Answer

i don`t have a pencil , here is a print screen with what i have :

Rich · Answer

What version of ARC have you got? I thought it was always there but there may have been a version where it wasn't. Download the latest version (today's version) and it should have the pencil... although I know it is in the previous version too.  If not, then add a script, throw in the commands as mentioned and in the command box for the movement panel use ControlCommand("Script", ScriptStart) where "script" is replaced for the script name.

sereandrei · Answer

Finally it`s working.

I have the following settings:

On a custom Movement Panel :

For stop : Set(D18, Off) Set(D16, Off) Set(D17, Off) Set(D15, Off) PWM(D16,0) PWM(D18,0) PWM(D15,0) PWM(D17,0)

For Fw: Set(D18, On) Set(D16, Off) Set(D17, On) Set(D15, Off)

For right : Set(D15, On) PWM(D16,-50) Set(D17, On) PWM(D18,50)

For left: PWM(D15, -50) Set(D16, on) PWM(D17, 50) Set(D18 , on)

For reverse: Set(D15, On) PWM(D16,90) Set(D17, On) PWM(D18,90)

Thanks again Rich ! you are the man !

Now is time to add some sensors !

Thanks all!

sereandrei

Ez-Robot And Zumo Robot

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