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I need to make a 6 DOF Robotic Arm with Stepper motors and encoders. Which MCU board should I choose for it? The board should have more than 34 GPIOs and should work well with Micro-Ros.
I've been working on a Moveo (mostly 3d printed 5dof robotic arm) build for a while. I've been using the teensy 4.1, microros, and teensyduino with pretty good success. My build has 5 steppers, and a servo. Steppers are driven with some TB6560 drivers, and I'm using as5600 magnetic encoders for joint feedback.
The problem I'm running into is that I haven't been able to use the accel stepper class to be able to move all 5 motors at speeds I'd like to, since I've got to do a bunch of other stuff (ie read encoder values, diagnostics, publish feedback, handle subscriptions, etc) on the teensy. To get around this, I'm going to try using pwm as the pulse for the motor drivers, and modify the pwm frequency. According to the teensy documentation, I've only got 7 timers, so I have to use a different timer for each motor. We'll see how it goes though.
Your project seems very interesting. I would like to know your progress as it will be good for me. "PWM to motor drivers" seems confusing to me because stepper drivers will require on/off frequency. How will you manage that?
These stepper drivers require a direction signal, and a "step" signal, the direction is set using a digital output on one of my teensy pins. The step signal just looks for a rising (or falling) edge of that step pin. So since I've got external encoders, I don't care to count every step to measure motor position. PWM will let hardware generate the pulses required by the motor driver. All I need to do is modulate the PWM frequency (not duty cycle) to change how fast the motors go. If I need to stop the motors, I can't set the frequency to 0, but I can do an analogWrite(STEP_PIN, 0) to make it stop.
I recommend you using STM32 family, they provide tools for selecting the correct MCU for your application. Then this component will ease you the micro-ROS integration: https://github.com/micro-ROS/micro_ro...
Hi Pablogs Can i use 64 pins Nucleo board which is not present in the micro-ros hardware supported list? Will it work?
Asked: 2022-07-28 05:52:00 -0500
Seen: 238 times
Last updated: Aug 02 '22
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