seanb
Hi there ezroboter's!
I'e been a lurker for quite awhile and fairly recently got my developer's kit. I'm having blast so far! I posted some months ago to inquire of the ez-b v4 board would support my Kobuki base which i received as part of a Turtlebot 2. It's a supercharged iRoomba/create (no vacuum parts, but quite a bit more power, lots of connections. Bigger battery, etc.).
Folks assistance in those early days is much appreciated as it allowed me to move forward, but I appear to continue to hit a wall. The Kobuki base is reportedly electrically compatible to the iCreate, however, I can't get the ice-robot Roomba project to connect.
If you look at the user's manual on page 10, you'll see the wiring diagram for the db25 serial port (linked below). The major difference between the iCreate and the Kobuki is that there's no ps/2 connector like the one is the video tutorial. I've got a servo (3 wire) plugged into D0 of my ez-b and disconnected the power wire. I've got ground going to pin 25 and the signal wire going to the pin 1(serial rx) on the kobuki. I have a suspicion that I should have my signal wire going to to the Kobuki's D10 which is its pin 3.
I figured I'd solicit the community's advice before moving forward. I have managed to get two arm's constructed from A12's Dynamixel's and a few other items integrated but this one worries me simply due to the cost of the Kobuki:)
http://gilbo.com.tr/kobuki/files/Kobuki-UserGuide.pdf" target='_blank' rel="nofollow">Kobuki Userguide
Your URL link is bad and will not load. The pins you mention are the same as what is used with the iRobot Create DB25 connector.
@Robot-Doc The link just had some unnecessary characters so this is the working one. Kobuki UserGuide
From what i understand from reading that guide you would need to change the firmware mode to Arduino/Embedded Board Support Mode Then connect these pins to the EZ-B to be able to receive bumper info as well as control the movement. It seems that you need to use the analogue ports to control the wheel speed, so I would try them on the EZ-B v4's analogue ports.
It also says to enable motors press button B0.
What are the capabilities of the Kobuki that you are trying to utilize?
I thought the ADC ports were incoming only. How would you vary outgoing voltage on those? Wouldn't you achieve the same effect by using PWM on a digital port?
Alan
Well from what I understand if you plug the AI0 and AI1 ports into a digital port on the EZ-B you will damage the speed controller, unless you use some type of voltage regulation. The digital ports are unregulated so whatever voltage the battery supplies, is what it outputs and for full speed forward they specify 3.3V.
I don't think it's currently possible to vary outgoing voltage on the analogue ports, as you said it only reads incomming, so then I would use a PWM on a digital port with a voltage regulator down to 3.3V
but it might be a little weird having the 0V as full reverse, since i guess as you set it up it would automatically start off in full reverse
The V+ pin on the digital ports is unregulated, but the signal pin outputs 0-3.3v variable through a PWM control or script command. So you would connect A10 and A11 to the signal pins on 2 digital ports. All the ports would/could share one ground.
Alan
@Alan How would you setup a stop value for the motors without having to disable and re-enable them? Would it simply be 50% on the pwm control
you would need to experiment with the PWM value to find the stop point. Disabling would be the same as 0, so full reverse, certainly not what you want. I haven't read the whole manual, so not sure how you would power it down, and what the start-up order should be. I would assume start up and initialize the positions of the EZ-B first, then power up the robot.
Alan
A quick look at the user guide and the protocol (the first thing to look at really) indicates it uses a serial interface at 115200 baud rate. See page 11 of the user guide.
Details for the serial interface can be found at http://yujinrobot.github.io/kobuki/doxygen/enAppendixProtocolSpecification.html
It looks to me the easiest method of control is through the serial interface, connect the RX of the EZ-B UART port to pin 1 of the DB25 connector and connect the TX of the EZ-B UART port to pin 2 of the DB25 connector. See page 9 of the user guide.