Search found 45 matches

by jwatte
Thu Aug 10, 2017 4:52 pm
Forum: General Discussion
Topic: How to convert x,y to motor speed1&2?
Replies: 2
Views: 3911

Re: How to convert x,y to motor speed1&2?

Yes, there are drive modes in the RoboClaw that can support this. Also, you can do the appropriate math in your own code. You don't say what code you're using to read the joystick. When you say you get "y=100" for forward, where do you get this? Are you using an Arduino, or a Linux box, or...
by jwatte
Tue Aug 08, 2017 10:22 pm
Forum: General Discussion
Topic: How to software reset a RoboClaw?
Replies: 7
Views: 8182

Re: How to software reset a RoboClaw?

you may be able to tell the R-Pi to disable the USB port to the Roboclaw(shutting off the 5v VBus). That has the side-effect of also turning off the Ethernet connection I'm using to connect to the Pi, the WiFi that's sending telemetry, and the microcontroller that I want to power. (And the touch sc...
by jwatte
Mon Aug 07, 2017 10:54 am
Forum: Velocity and Position Control
Topic: Encoded motor recommendations
Replies: 11
Views: 14284

Re: Encoded motor recommendations

That's interesting! When I run those motors and hook a scope to the encoders, the signal actually looks clean, but I can't run them under load with the scope connected (don't have a dyno or anything like that.) Are you suggesting that the cap on the board would pass enough HF that it would make the ...
by jwatte
Mon Aug 07, 2017 10:48 am
Forum: General Discussion
Topic: How to software reset a RoboClaw?
Replies: 7
Views: 8182

Re: How to software reset a RoboClaw?

The +5v going to RPI is not also going to the Robcolaw correct? What's missing in the diagram is the label "USB" for the connection between RPi and MCU. USB does both data and power. The RPi has an on-board "ideal diode" to make forward/back feeding of the 5V rail okay. Note the...
by jwatte
Sat Aug 05, 2017 2:03 pm
Forum: Velocity and Position Control
Topic: Encoded motor recommendations
Replies: 11
Views: 14284

Re: Encoded motor recommendations

Another option, if you want gearbox, motor, and encoder all integrated into one nice package, for a reasonable price, is the Pololu D37 gearmotors. They're not super powerful, so if you need something that's both torque-ey and fast,you might do better with something you assemble yourself. https://ww...
by jwatte
Sat Aug 05, 2017 1:58 pm
Forum: General Discussion
Topic: How to software reset a RoboClaw?
Replies: 7
Views: 8182

Re: How to software reset a RoboClaw?

Yeah, the problem is that the power bus pulls up to 4V or so when only the MCU is powered. It can sit like this for a bit before it goes to full power on. This causes the 'claw to detect logic undervoltage, and thus it won't come out of error, even when the power bus comes back up to full voltage. T...
by jwatte
Sat Aug 05, 2017 1:28 pm
Forum: General Discussion
Topic: How to software reset a RoboClaw?
Replies: 7
Views: 8182

Re: How to software reset a RoboClaw?

You should not have an external 5v connected to the Roboclaws 5v I don't -- it's likely powering itself from the pull-up on the serial port on the MCU or perhaps there is some path to the motor power from the 5V regulator (presumably backwards through the other 5V regulator that's not powered.) a L...
by jwatte
Tue Aug 01, 2017 5:07 pm
Forum: General Discussion
Topic: Why does this one RoboClaw light red when running?
Replies: 8
Views: 8893

Re: Why does this one RoboClaw light red when running?

Thanks for the answer! I find that there is a little bit of voltage loss as the motors are running, because I'm using "good enough" but not super fat wiring in my distribution harness. However, I have a separate microcontroller measuring the battery voltage where it comes in to the system,...
by jwatte
Tue Aug 01, 2017 5:01 pm
Forum: General Discussion
Topic: Fuse/Breaker Recommendations
Replies: 11
Views: 12840

Re: Fuse/Breaker Recommendations

Additionally, motors don't like being stalled. They don't like being run at close to stall power for too long. They will overheat. Good motors have a specification for duty cycle and "normal" amount of current (which is typically 25% of stall current, or lower!) Bad motors don't have this ...
by jwatte
Tue Aug 01, 2017 4:48 pm
Forum: General Discussion
Topic: How to software reset a RoboClaw?
Replies: 7
Views: 8182

How to software reset a RoboClaw?

I have RoboClaws in an embedded system that can self-program. While it's self-programming, the motor power is off, but enough current leaks from the 5V rail into the RoboClaw that they power on, and detect logic battery under-voltage. Once the system has self-programmed, it comes back, and turns mai...