
mdeming1

Hi all.
First post. I got my ezb two Christmases ago to build a robot idea I had. Life happened and now I'm finally ready to build. I feel a bit daft as I'm able to get a few things right and others I'm not having success with. Here is the plan: a custom frame robot with two jazzy wheel chair motors and a third dead wheel for balance, the robot will follow a set path at a set time and return on the same path (assuming no obstacles) at a set time and plug itself in to charge.
I rigged up a bare bones set up using the ez-b, a sabertooth 5x25 mc, two wheelchair motors with brakes removed and a 12 battery. I know my wires are currently sloppy but it was just a quick test.
I got the ez-b connected wirelessly (using the gui)and powered from the 5v output on the sabertooth. I set the pins as described in other posts. I was able to get one motor turning forward and back using the ez-b virtual joystick (sabertooth) but it wouldn't stop turning. The other motor did not turn. Now, I know that I only had one signal wire connected to the ez-b but I'm not sure that it would support wires on different connectors. I also didn't see anyone else's diagrams powering the ezb via 5v from the mc. I've attached a basic diagram below.
I guess my questions are: what would you recommend I change on my wiring? Can anyone advise as to what I need to add to accomplish the stated goals? I've read a ton of posts and forums and they've been helpful but I also really could use some friendly guidance from someone who's been there.
I hope this made sense and really appreciate any and all assistance.
Matt
Only thing you might want to try (and this doesn't really make sense with the symptoms) is to power your EZ-B independently rather than using the 5v BEC of the Sabertooth. The 5V BEC is only 1 Amp which is a little low for the EZ-B (although with nothing else being controlled should be sufficient) and the EZ-B actually runs a lot better on 7.5 volts than 5 (although again, shouldn't really be an issue with only one connection). If you do this, be sure to tie your grounds together or it definitely won't work.
The S2 is used when using the Sabertooth in R/C mode (you connect one signal to S1 and 1 to S2 and treat them as servos with a regular movement panel) but Serial mode has been much more reliable for users since DJ created the Sabertooth control panel.
Alan
I'm sure this is an easy something I'm missing. Both components have been really well made and easy to use.
Any additional ideas?
Thanks
Matt
Has anyone had luck with other pin settings? I'm sort of at a loss.
thanks
Matt
Code:
If that works correctly then the problem is in the config for the Sabertooth Movement Panel. If it doesn't work then the problem is with the wiring or the setup of the Sabertooth.
The pin settings should be as shown on the Sabertooth help page. This should put the sabertooth in Simplified Serial mode with a baud rate of 38400.
It shouldn't make any difference but you could also try on a different digital pin, D0 for instance.
Alan
more later.
Matt
Meanwhile, this current robot is the whole reason I got the board in the first place. I'm hoping to implement:
Map following
IR control
Action to take a certain times (a clock or date time function)
I'm going to see what I can do to add these functionalities and I'm certain i'll need your assistance again. I really appreciate everything. Not sure why only D0 works but i'll take it.
best
Matt
I can only choose one resolver but since this was a group effort i'll offer thanks for resolution to:
Rich
Richard R
Darathian
Danger!
thetechguru
RobotDoc
Thanks for not giving up on my issue.
********EDIT*********
The D0 port testing I did on all 3 EZ-Bs was confined to the 57,600 and 115,200 baud Roombas. The Roomba commands will not work on any other digital ports on any of my V3s. I have the latest firmware flash on all three boards.
I never looked in to it much as it is something I cannot afford to get interested in but D0 is the only port the Roomba can use and I believe it may be due to the baud rate (I can't afford to get in to the whole Roomba thing as they are ridiculous money over here). However, @Anthony is using multiple Sabertooth's (Saberteeth?) with Lexi and I believe @Dave may also be using multiple Saberteeth on his B9 (I may be wrong on that one) so they should work on any Digital port.
FYI, if you use the latest ARC you are forced to upgrade to the latest firmware too. As far as I know all V3s are pretty much the same (other than a few minor component changes) so all should use serial the same way. I will add checking serial and baud rates etc. on all 20 ports to my to-do list, it'll be a fun little project and be something to break up the mundane list of tasks I an fighting with currently
Glad it's sorted now though. As for the other questions, feel free to ask. Search the forums too, the time based one has been discussed/explained previously (however if you can't find it or need more specific help it's no issue, we are here to help).
I have also used D8 on my TellyMate examples, these were a baud rate of 57600.
While I don't have projects to confirm it, I do know (from memory) that I have used a whole range of digital ports for serial communications and not had any issues. To put it bluntly, I never really cared which port I plugged in to. The only serial issue I experienced was twitching servos (on other ports) when sending serial commands to my first LCD display (on both EZ-Bs I have and on multiple projects), I do not know if this was fixed as I changed the LCD to I2C so I didn't have to deal with the problem
I know D0 is the only port which had the ability to communicate at a specific baud rate...
Reading this post DJ explains baud rates a bit. Basically, the V3 maxes out at 57600 for all 20 ports with the exception of D0 which can do 115200. So if your baud rate was set to higher than 57600 this would explain why it wasn't working on anything but D0. If it was below 57600 then we are still none the wiser.
Sorry for the wires. After solving the issue I had I decided to do my other functionality experiments on a smaller platform first so I got out an rc car and a smaller sabertooth [edit, this is not a sabertooth! it is an L298N chipset 2.5 amp motor controller available from ez robot store] had ordered from ez-b way back when and never opened. Haven't tested it out yet.
Thanks
Matt
Edit here and above: the controller is an L298N chipset 2.5 amp motor controller available from the ez robot store