This is probably from my ignorance in electronics but...
Is there any need for concern when connecting an external battery pack for motor power supply with a higher/lower voltage than the EZ-B battery pack ie... 4.5-13V grounded against 5V?
And if i did miss something, where would you ground the external motor battery pack to on the Hbridge?
We all got questions and this is the best place to ask em'. You are definitely correct in assuming that the motor driver can drive voltages higher than 5V, this board can use 4.5-13v up to a max of 15V. As DJ had mentioned above, just place your external battery positive voltage to the VM pin, and it may not have been mentioned, but connect one of the GND lines to the negative side of the battery and this will give your circuitry all a common ground reference as I believe all the GND lines on the motor driver board are connected together.
Hi all, got a couple questions about this Hbridge as I have a couple and want to use the PWM for variable speed, if I do does this mean I would use up another 2 digital (servo) ports on the EZB for a total of 6 ports to get this to work? If this is correct, do I just need to use the signal from these 2 extra ports for PWM?
Also, I'm not sure if my eyes are fooling me, but I've watched DJ's video above a few times and I'm sure that the white wire in this image should go to the outside of the board and black (ground) should be in the center of the board. Is this just an oops in the video or am I missing something?
So I found some info that said that this Hbridge can be controlled with a PWM signal to the two Ain and Bin enable pins and just leave the PWM pins wired to the 5vdc as DJ recommended here. So I wired it up to the spec above and have no problems using the ARC Hbridge control.
So I started designing a C# program to control this Hbridge with PWM on the Ain and Bin pins. What I came up with works but there is a small glitch, and I have no idea if it is programming (timing), the hbridge or the EZB board.
Basically I'm using 4 servo controls to move the Hbridge. This works well, but the only way to stop it is to release the servo. You can stop the PWM signal by setting it to zero but this applies a brake function. So you can still go one direction with Ain 1 at servo position 50, but if Ain 2 is at position 0 (stopped) then it will be applying brake which will move, but it uses up power and won't allow maximum speed to be achieved. The solution was to use DJ's release servo command. However when I use this on all 4 pins, one seems get "set" which causes the robot to spin. It seems to be random on which one will get set.
So I've tried just releasing the ones that need releasing rather then all 4 before I initiate a pin. Example, I release Ain1 if I'm going to set Ain2 to a value. This seems to have cut down on the glitches, but I want it perfect
I've also tried using a timer to release them with different periods but I still see this glitch happening. I would like to blame the problem on the Hbridge, but I don't think this is it. I have no problem except when I try to release the servo, I have been successful at sending a different PWM signal to the Hbridge while it is on the move. Example, moving forward, so Ain1 and Bin1 receiving PWM, Ain2 and Bin2 released, I resend a new servo command to increase speed from 30 to 50, never get the glitch! But if I stop or change direction, meaning new arrangement of pins are enabled and disabled then I will get a problem almost a quarter of the time (estimated).
I would be more then willing to post my code here if someone wants to look at it, but right now it's a mess from trying to fix this thing. I will try to get the most stable configuration I can and post that later a bit cleaned up.
I'm using EZ-B SDK Windows v2011.12.05.00 if anyone thinks that a newer version will help I will give that a try, but it may be something electronic, maybe a resistor or capacitor would help, but I don't know much about that.
There are no silly questions, I think that came from a movie
+5 is just a way to designate the Positive hookup for the DC voltage. This means this connection would be hooked up to + 5 volts direct current. Other common voltages on circuits are +3 and +12 (there are lot more variations, but you will see this the most)
Thanks DJ,
That was an old post above, I let the smoke out of the sparkfun a while back and went on to use 2 VEX Motor Controller 29 units. They have worked great so far and are less expensive. One day when I play with a HBridge again I will try out the new PWM controls.
This is probably from my ignorance in electronics but...
Is there any need for concern when connecting an external battery pack for motor power supply with a higher/lower voltage than the EZ-B battery pack ie... 4.5-13V grounded against 5V?
And if i did miss something, where would you ground the external motor battery pack to on the Hbridge?
Hi Luis1983, welcome to you if you're new here!
We all got questions and this is the best place to ask em'. You are definitely correct in assuming that the motor driver can drive voltages higher than 5V, this board can use 4.5-13v up to a max of 15V. As DJ had mentioned above, just place your external battery positive voltage to the VM pin, and it may not have been mentioned, but connect one of the GND lines to the negative side of the battery and this will give your circuitry all a common ground reference as I believe all the GND lines on the motor driver board are connected together.
Hi all, got a couple questions about this Hbridge as I have a couple and want to use the PWM for variable speed, if I do does this mean I would use up another 2 digital (servo) ports on the EZB for a total of 6 ports to get this to work? If this is correct, do I just need to use the signal from these 2 extra ports for PWM?
Also, I'm not sure if my eyes are fooling me, but I've watched DJ's video above a few times and I'm sure that the white wire in this image should go to the outside of the board and black (ground) should be in the center of the board. Is this just an oops in the video or am I missing something?
So I found some info that said that this Hbridge can be controlled with a PWM signal to the two Ain and Bin enable pins and just leave the PWM pins wired to the 5vdc as DJ recommended here. So I wired it up to the spec above and have no problems using the ARC Hbridge control. So I started designing a C# program to control this Hbridge with PWM on the Ain and Bin pins. What I came up with works but there is a small glitch, and I have no idea if it is programming (timing), the hbridge or the EZB board. Basically I'm using 4 servo controls to move the Hbridge. This works well, but the only way to stop it is to release the servo. You can stop the PWM signal by setting it to zero but this applies a brake function. So you can still go one direction with Ain 1 at servo position 50, but if Ain 2 is at position 0 (stopped) then it will be applying brake which will move, but it uses up power and won't allow maximum speed to be achieved. The solution was to use DJ's release servo command. However when I use this on all 4 pins, one seems get "set" which causes the robot to spin. It seems to be random on which one will get set. So I've tried just releasing the ones that need releasing rather then all 4 before I initiate a pin. Example, I release Ain1 if I'm going to set Ain2 to a value. This seems to have cut down on the glitches, but I want it perfect
I've also tried using a timer to release them with different periods but I still see this glitch happening. I would like to blame the problem on the Hbridge, but I don't think this is it. I have no problem except when I try to release the servo, I have been successful at sending a different PWM signal to the Hbridge while it is on the move. Example, moving forward, so Ain1 and Bin1 receiving PWM, Ain2 and Bin2 released, I resend a new servo command to increase speed from 30 to 50, never get the glitch! But if I stop or change direction, meaning new arrangement of pins are enabled and disabled then I will get a problem almost a quarter of the time (estimated).
I would be more then willing to post my code here if someone wants to look at it, but right now it's a mess from trying to fix this thing. I will try to get the most stable configuration I can and post that later a bit cleaned up.
I'm using EZ-B SDK Windows v2011.12.05.00 if anyone thinks that a newer version will help I will give that a try, but it may be something electronic, maybe a resistor or capacitor would help, but I don't know much about that.
Thanks for any advice Chris
Feel free to make fun of me if this is a silly question.
Can someone tell me what +5 means?
I'm so new and don't know one iota about wiring, but I can follow the video pretty well.
There are no silly questions, I think that came from a movie
+5 is just a way to designate the Positive hookup for the DC voltage. This means this connection would be hooked up to + 5 volts direct current. Other common voltages on circuits are +3 and +12 (there are lot more variations, but you will see this the most)
Hope that helps.
@Sirlal Use the PWM and not servo controls
Thanks DJ, That was an old post above, I let the smoke out of the sparkfun a while back and went on to use 2 VEX Motor Controller 29 units. They have worked great so far and are less expensive. One day when I play with a HBridge again I will try out the new PWM controls.