Operate a Pneumatic air cylinder for Z-Axis movement

philmurp
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by philmurp » Thu Nov 14, 2013 5:23 pm

cvoinescu wrote:That's correct, and should work. D9 is the X limit switch. Have you enabled the limits in GRBL? I believe it's $16.
That could be the issue. However when I try and change it in my G-Code sender I get the following error:

Is there another way to access GRBL to configure settings, or could this be because I am using GRBL .8a and not .8c?

Thanks
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cvoinescu
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by cvoinescu » Fri Nov 15, 2013 9:20 am

0.8a does not have support for homing and limit switches. 0.8c does.
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philmurp
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by philmurp » Fri Nov 15, 2013 4:08 pm

That is what I expected. It seems that .8c has a lot more functionality than .8a. Is there any way to just hard wire the limits to the power supply similar to the emergency stop button(perhaps in parallel with the emergency stop button?)

Additionally do you know of any software G-Codes that limit what coordinates can be sent to the motors?

Thanks,
Philmurp

cvoinescu
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by cvoinescu » Fri Nov 15, 2013 4:52 pm

GRBL 0.8 does not have soft limits, and I don't think 0.9 does either. There are no G-code commands for that, they are usually machine-specific parameters (so if GRBL had them, they'd be $ commands to set the respective configuration variables).

It's unlikely that you can wire the limit switches the same way as the emergency stop button, because they can't carry the motor driver supply current. You could wire them in series with the ENABLE pin, so that if any is pressed, the motor drivers get disabled (but make sure the ENABLE is pulled up, not down -- on the buildlog.net stepper shield, it's pulled up, which would not be useful). Or you can wire them in parallel with the RESET button of the Arduino. Still, I would upgrade to 0.8c, because that has nice support for homing -- why insist on 0.8a?
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

philmurp
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by philmurp » Fri Nov 15, 2013 5:15 pm

[quote=" Still, I would upgrade to 0.8c, because that has nice support for homing -- why insist on 0.8a?[/quote]

I would definitely like to upgrade to .8c but I purchased a shield/seeeduino bundle with grbl already installed from synthetos.com. I am not sure how I can go about upgrading my grbl since it was a preloaded bundle. As well when I look online, it seems I may need an external AVR programmer in order to update. If it was easier I definitely would update, but for now I guess I will have to pay close attention and be ready with the emergency stop button :/ .

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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by cvoinescu » Fri Nov 15, 2013 11:08 pm

The Seeeduino should be upgradeable via USB, if it has the Ardunio bootloader.

If it doesn't, then yes, you need a programmer -- or another Arduino and a few wires to connect them together. There is an Arduino program that acts as a programmer for another Ardunio (I forget the name). You can use that to burn the firmware onto the Seeeduino, and then upload GRBL 0.8c to it the usual way, via USB.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

philmurp
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by philmurp » Sun Nov 17, 2013 11:44 pm

cvoinescu wrote:The Seeeduino should be upgradeable via USB, if it has the Ardunio bootloader.

If it doesn't, then yes, you need a programmer -- or another Arduino and a few wires to connect them together. There is an Arduino program that acts as a programmer for another Ardunio (I forget the name). You can use that to burn the firmware onto the Seeeduino, and then upload GRBL 0.8c to it the usual way, via USB.
Since I bought my seeeduino as a bundle, it doesnt have the Arduino bootloader on it.

I have done some research and found a tutorial online on how to use an Arduino UNO as an ISP Programmer in order to send Hex files to an Arduino.
The link is: https://www.sparkfun.com/tutorials/247
This other tutorial seems to be a great way to do it: http://www.synthetos.com/wiki/index.php ... ng-Method3
However it is based upon having an AVR programmer. If I am using an arduino UNO as the ISP can I proceed as if I am using an AVR programmer once I have the arduino setup as a programmer?

This seems like it will work, however I was wondering if you could take a look and see if this is the correct way to flash the hex file to my board. I am nervous about upgrading because my current system does work with the .8a, but it definitely has limited functionality when I compare it to .8c (coolant control, limit switches, homing cycle)

Thanks,
Phil

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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by cvoinescu » Mon Nov 18, 2013 12:12 pm

The Sparkfun tutorial is the one I was talking about. According to reports I've seen, it works. Once you've got the bootloader installed on the Seeeduino, you can use XLoader or even the Arduino IDE to upload the firmware via USB, no programmer or second Arduino needed. Just follow the instructions on the GRBL Github wiki.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

philmurp
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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by philmurp » Wed Nov 20, 2013 3:43 pm

cvoinescu wrote:The Sparkfun tutorial is the one I was talking about. According to reports I've seen, it works. Once you've got the bootloader installed on the Seeeduino, you can use XLoader or even the Arduino IDE to upload the firmware via USB, no programmer or second Arduino needed. Just follow the instructions on the GRBL Github wiki.
Just to confirm, the sparkfun tutorial not only loads a bootloader onto my board but then flashes the hex file? So if I follow that tutorial start to finish I should have a full update to .8c done?

Or would it be easier to just use Arduino to burn the bootloader, and then Xloader to flash the .hex file as shown in this arduino tutorial:

http://arduino.cc/en/Tutorial/ArduinoISP

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Re: Operate a Pneumatic air cylinder for Z-Axis movement

Post by cvoinescu » Wed Nov 20, 2013 9:26 pm

I'm pretty sure the Sparkfun tutorial turns the Ardunio into a full programmer, so you could burn both the bootloader and the firmware (GRBL). However, if you're not careful, burning the firmware will erase the bootloader -- so it's easier to burn just the bootloader with the other Arduino, then burn the GRBL .hex the usual way, via USB.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

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