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AccelStepper used with stepper shield 1438
Moderators: adafruit_support_bill, adafruit

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Re: AccelStepper used with stepper shield 1438

by efrank03gps on Wed Jul 19, 2017 1:25 pm

Thanks, this worked perfectly and now I understand that the way you call a command determines what system of commands it executes. For example, runSpeed() is a command in both AccelStepper and MotorShield, but they work differently. Unfortunately, this approach using 1438 won't be adequate for my purposes because even using oneStep for stepping both motors, the max speed is only about 200 steps per second, which is not fast enough. I am instead using a MetroMini to drive the steppers directly via a UN 2803 chip. The robot's computer communicates with the MetroMini via I2C. Works well. Your answers to my questions have been most helpful. Thanks again!

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Re: AccelStepper used with stepper shield 1438

by adafruit_support_bill on Wed Jul 19, 2017 1:30 pm

The maximum stepping rate is typically limited by the i2c clock rate. By default, most processors use 100KHz. You can usually increase that to 400KHz. There is a function in the Arduino wire library to set the clock speed.

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Re: AccelStepper used with stepper shield 1438

by efrank03gps on Thu Jul 20, 2017 5:41 pm

Yes, that speeded things up more than 2-fold. Thanks for the tip.

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Posts: 22
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Please be positive and constructive with your questions and comments.