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[telfish]

Having got the software working fine with the Mega I used a couple of TB6600 drivers to test. The steppers move fine as long as I have the enable- disconnected, this means the steppers are permanently energized even when the scope is parked. Also as I change microstepping from the dip switches the slew and track rate changes proportionately. This does not seem right. At high speed the motors stall after a couple of revolutions and make a high pitched sound until the slew is over.

I have tried all ways to wire the enable line if it is as normal with ena+ to 5v and ena- to the enable pin I get no movement, if reversed the same.

Am I supposed to wire the MS1 to 3 outputs low or high, right now they are just floating.

This is the unit I am using.

https://www.amazon.com/MYSWEETY-TB6600-Stepper-Driver-Controller/dp/B01MYMK1G9/ref=sr_1_3?s=industrial&ie=UTF8&qid=1515511724&sr=1-3&keywords=tb6600+stepper+driver


Terry

[TCWORLD]

Also as I change microstepping from the dip switches the slew and track rate changes proportionately. This does not seem right.

If you change the microstepping mode of the drivers, the speed of the motor will change. The MCU doesn't know that you have changed the step rate, it will simply keep stepping at the same rate.

You'll need to set the microstep mode to what you require, ensuring that the value set in the config setup, and the value selected on the driver match match. As the MCU can't change the microstep mode, you will also have to ensure that "Gear Changing" is "Disabled" in the config setup.

Am I supposed to wire the MS1 to 3 outputs low or high, right now they are just floating.

MS1 to 3 are outputs from the MCU. They aren't floating but rather driven high or low by the MCU. You can leave them unconnected

At high speed the motors stall after a couple of revolutions and make a high pitched sound

If the motors stall, you are trying to spin them faster than they are capable of going.

The steppers move fine as long as I have the enable- disconnected, this means the steppers are permanently energized
...
I have tried all ways to wire the enable line if it is as normal with ena+ to 5v and ena- to the enable pin I get no movement, if reversed the same.

The MCU expects the driver to be disabled when it outputs high (5V), and enabled when it outputs low (0V). This is the opposite behaviour to the TB6600.

You should instead connect the EN+ of your driver to enable pin of the MCU, and EN- to GND.

[telfish]

Thanks Tom, sorry to be a pain.

I think I understand. If I set the micro-steps in the driver and in the control panel to 32 then there is no way for it to change to a faster stepping mode for slewing and I am stuck with a really slow slew. In which case these drivers are not really suited and I will go back to the 8255's

Thanks for the explanation I did adjust things as you suggested and even with the enable as you said the steppers are still energized when parked or before connection.

Is there any way for me to measure a complete revolution of the stepper in time to see if the EQ6 "scope" is tracking at the right rate?

Also did you get the order for the board chips and leads I made over the weekend?

Terry

[TCWORLD]

If you divide the equatorial day (86164.0905 seconds) by the worm gear ratio (180:1 I believe), you will get the time period for the worm screw. The easiest way to check if the rate is correct is to time one revolution of the screw and see if it matches the required period.

Depending on your gear ratios, AstroEQ should be able to achieve ~300x speed even with gear checking disabled.

Not sure about the enable then. Might be worth checking with the seller.

In terms of chips order, I've posted all orders I've received. If you didn't get a confirmation e-mail from "notifications@ecwid.com" and PayPal, it probably didn't go through (seems to be an issue with the web store I use that I can't fix).

[telfish]

Thanks, I will re order.