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Motor HAT does not release power unless you explicitly tell
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Motor HAT does not release power unless you explicitly tell

by theITguyfromNY on Wed Jan 30, 2019 2:16 pm

Note: This is an off-shoot of recent posts from the "Stepper Speed limitations with MotorShield v2" thread, but this is a different issue, so created new thread.

ENVIRN: Raspberry Pi 3+ running under completely normal circumstances. NEMA 17 #324 stepper with #2348 HAT. Adafruit MotorKit and Stepper Kit installed and nothing re-configured (i.e. normal I2C bus speeds, etc).

To RE-RUN TEST: Plug in 12V/1.5A power supply to the HAT, power up Rpi, green power LED lights up on HAT (designating normal power), let it sit for a long time, motor is NOT hot.
Run code "For stepper motors" at very bottom of page (https://learn.adafruit.com/adafruit-mot ... cuitpython) just one time. Motor activates quickly and program ends...motor is not hot. (obviously this is code is only a quick blip of power). But...wait a while (several minutes), and motor is EXTREMELY HOT (can't even really touch it). ?!?!? (After unplugging the HAT power, motor cools down quickly).

The code "For DC motors" right above the stepper code shows releasing power using "kit.motor1.throttle = 0"; for steppers, though, it does NOT show this "release" function...so I did not include one. I'm wondering now if I need to do this same release...like...always??

Is that what is making this hot?

theITguyfromNY
 
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Joined: Thu Jan 24, 2019 12:33 pm

Re: Motor HAT does not release power unless you explicitly t

by adafruit_support_carter on Wed Jan 30, 2019 7:50 pm

It may be as you are suggesting. Sounds like it's not de-energizing when done moving. Try modifying the example like this:
Code: Select all | TOGGLE FULL SIZE
"""Simple test for using adafruit_motorkit with a stepper motor"""
from adafruit_motorkit import MotorKit
     
kit = MotorKit()
     
for i in range(100):
    kit.stepper1.onestep()
kit.stepper1.release()

adafruit_support_carter
 
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Joined: Tue Nov 29, 2016 2:45 pm

Please be positive and constructive with your questions and comments.