Micro Switch triggering stepper motors

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

I am using a 1000 PSU
1000 what? Volts? Amps? Watts?

I don't see any obvious shorts caused by the wires you soldered to the board. Try removing them and see if the problem goes away.

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jbc
 
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Re: Micro Switch triggering stepper motors

Post by jbc »

1000 Watts.
I'll do that and report what happens later tonight.
Thank you.
jbc

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

1000 Watts.
That is still only half the information we need. How many volts is it?

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Re: Micro Switch triggering stepper motors

Post by jbc »

The PSU:
Guaranteed to deliver 1000W of continuous power at 50°C
80%+ energy efficient under real world load conditions
Combined 80A of power on +12V
105°C solid state capacitors
Active Power Factor Correction (PFC) with PF value of 0.99 to ensure clean and reliable power
Supports the latest ATX12V 2.2 and EPS12V 2.91 Standards. Backwards compatible with ATX12V 2.01
Auto switching circuitry provides universal AC input 90-264V
Over Current/Voltage/Power Protection, Under Voltage Protection and Short Circuit Protection provide maximum component safet
I cut the red wire connecting the prototype area and the ground pin.
I also tried using different set of wires running from the PSU for the power.

The other 9 Adafruit motor shields are running fine and the PSU lights up the boards and drive the motors as if working hard for a promotion.

This board had at one time powered up two steppers but must have been damaged while I tinkered with it attaching the switch.........no?

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

This board had at one time powered up two steppers but must have been damaged while I tinkered with it attaching the switch.........no?
It is not common, but I have seen it happen. If there is a short-circuit or other serious overload, the H-Bridge chip can have a meltdown internally. Usually they fail open-circuit. But I have seen a couple that fail in a short-circuit. Often (but not always) this is accompanied by a flash and/or puff of smoke from the chip.

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Re: switch qustion

Post by jbc »

Bill,
I got my new adafruit motor shield and soldered the micro switch in place and stacked it on top of the other shields like the time before.
Same result=PSU protects the system by turning off. I don't believe the shield is the problem. And judging by your reaction to the pictures I showed you last week my wiring is not the issue.

Could i2c have a conflict with one of the other i2c's addresses?
I played with some of the connections and got the offending shield to power up but then noticed another shield (no switch attached to any shields but i2c 069 shield) was not powered.
I checked connections on that one and then the top shield with the micro switch gave me the PSU turning off issue again (original issue).

The shield with the micro switch attached to the prototype area has an i2c addrress of 069 01011
The shield that turned off while powering the shield with i2c 069 has address 067 01000

jbc

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Re: switch qustion

Post by jbc »

I made a new address on the shield I thought was a problem (last week).
Changing the address did not correct the issue.

I had ten shields stacked on top of an Arduino Uno. I took one off but kept the one with the micro switch attached and then I flipped the power switch on and as the clouds parted the angels began to sing....all of the shields powered up but with a max of 9 shields, 10 was too many.

Why would that be?
Have you guys tried stacking more than 9 shields on an arduino?

jbc

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Re: switch qustion

Post by jbc »

I mistakenly posted the above posts in the wrong discussion.
Can you please move them to-
http://forums.adafruit.com/viewtopic.ph ... 2&start=30

Thank you.
jbc

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

(Posts moved)
Hmmm. I have not tried 10 shields personally. I see no reason on paper that it should not work. But you know what they say about theory vs practice. :wink:

Address conflicts should not cause a power supply issue. You would just have 2 shields responding to the same commands. I could see maybe 10 shields starting to tax the 5v supply on the Arduino, but you are tripping your external motor supply with no motors attached :?

If you disconnect the external power supply, can you stack up 10 boards and still load & run an Arduino program?

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Re: Micro Switch triggering stepper motors

Post by jbc »

I had stepper motors attached to all 10 boards with one board (top most) having the switch attached (also tried without switch) to pin 13.
The sketch loaded on the Uno does not set any motors in motion unless I tell them to move so they were all in 'release' status and turn freely.
I used two sets of wires sending power and GND to (4) power distribution blocks so I would hope the power from the PSU would be plenty...but I have proven to know nothing.
If you disconnect the external power supply, can you stack up 10 boards and still load & run an Arduino program?
I'll try that when I get home and report back.

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Re: Micro Switch triggering stepper motors

Post by jbc »

I ran my sketch without the power on.
Here is what the serial monitor showed:
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3
Estimated pre-scale: 2.81
Final pre-scale: 3

That's all 10 shields. As far as I know the Uno wouldn't report anything.

I am running two separate power wires from the PSU and two separate ground wires.

Thoughts?

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

OK. So 10 shields stacked all communicate fine. The problem seems to be related to your external power connections. (That makes sense, since it is your external supply that is tripping).

From what I can see, the only connection from board-to-board for the external power supply is the ground. If you have the 10th board connected to the external power supply but not stacked on the Aruduino, does it still trip?

This is officially weird. I may have to round up a pile of boards and try to reproduce this.

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Re: Micro Switch triggering stepper motors

Post by adafruit »

At the level of complexity, this project may start to push levels of engineering that go from "maker casual" to "requires an EE" - there may be too much inrush capacitance, or possibly quiescent current. You may want to split your project up into two controllers to drive 20 steppers!

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Re: Micro Switch triggering stepper motors

Post by jbc »

If you have the 10th board connected to the external power supply but not stacked on the Aruduino, does it still trip?
yes
- there may be too much inrush capacitance, or possibly quiescent current.
I would Google those words to understand the problem but I am rushing out the door.

When the system is turned on none of the motors are given power (with 9 or less boards)

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Re: Micro Switch triggering stepper motors

Post by adafruit_support_bill »

I would Google those words to understand the problem but I am rushing out the door.
When you power up the system, the power supply needs to charge the capacitors on all 10 boards. These are sizeable capacitors designed to smooth out voltage fluctuations due to peaks in current demand from the motors. Even though the motors are not running, the combined capacitance represents a substantial load to the power supply at startup.

The quiescent current is what the chips themselves draw when idle. Although small, this could be a contributing factor as well.

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