Nardeus2K
Posts: 6
Joined: Wed May 30, 2018 11:31 am

Re: Gertbot

Fri Jun 08, 2018 12:38 pm

Hello,

First of all, thanks a lot about your quick response. I'm sorry I haven't had much time to either test it or come back to you on my tests.
I must confess I'm still not quite familiar with the parameters speed, ramp and flags, especially the last one, in servo_config(board,channel,speed,ramp,flags,trim_min,trim_max).
Speed and ramp must be specified how so?
As for the rest I'm assured the command lines are well designed.

Thanks a lot for your time.

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Gert van Loo
Posts: 2478
Joined: Tue Aug 02, 2011 7:27 am
Contact: Website

Re: Gertbot

Fri Jun 08, 2018 12:54 pm

I am working on an updated manual. There is a delay because I am switching from word to open-office and there are
compatibility issues. I have to do a lot of tedious work and I can stand only so many hours a week with elevated blood pressure!

The new manual states that you should just set the speed and ramp to zero.
Only use them if you find you have some issues with the motion.

Flags does nothing. It is for a feature which is not there yet.

I would appreciate any feedback on the drivers.
If I hear that they work, I can move them from alpha-status to release-status.

Nardeus2K
Posts: 6
Joined: Wed May 30, 2018 11:31 am

Re: Gertbot

Fri Jun 08, 2018 1:31 pm

Hi,
Using the following commands, I observe no movement, nor locking of the servo:
gb.servo_config(BOARD,0,0,0,0,1000,2000)
gb.servo_pos(BOARD,0,500)

tell me if there's any issues with my writing of the lines.

Thanks a lot for your time.

Nardeus2K
Posts: 6
Joined: Wed May 30, 2018 11:31 am

Re: Gertbot

Thu Jun 14, 2018 9:12 am

To make sure I didn't mess up in my wiring I include here my photo of wiring https://ibb.co/hpxaed

Please tell me as soon as you have some time for it if there's anything wrong with my side of things.

Thanks a lot

Nardeus2K
Posts: 6
Joined: Wed May 30, 2018 11:31 am

Re: Gertbot

Mon Jun 18, 2018 2:34 pm

Hello,

You do not need to further concern yourself using the servos, I've been told, it's a pointless ordeal using your board trying to control using your pins, as there are some left when plugging in your board. We just set some of the pins to GPIO and use PWM control fromthe GPIO toolbox on Python.

Thanks again for your time, and if I've ever incomodated you with a dumb question I'm sorry.

cbear92
Posts: 1
Joined: Sun Sep 09, 2018 10:47 pm

Re: Gertbot

Sun Sep 09, 2018 10:55 pm

Hi Gert,

I was hoping to get some advice about the features of the Gertbot? I am looking for some stepper motor control as part of my PhD. Part of that is using a ramped data, which is a list of different frequencies steps that all together represent a particular velocity/accel. profile. Is there a way to feed in this data and have the motor run unninterrupted? Or would this have to be coded to recognise when the current steps have been finished before sending out the next line to be run? If this is the case, would this be limited to the 1 ms read steps timing and what would the deadtime between lines end up being?

I was also wondering if the Gertbot could run lower power stepper motors < 8 V?

Cheers,
Cbear92

olio
Posts: 17
Joined: Tue Feb 02, 2016 8:55 am

Gertbot connect relay to digital input and read state (open, close)

Tue Nov 06, 2018 7:07 am

Hello,
maybe my issue is too simple that I can't find any example for it or I'm blind?.
I would like to connect a closing relay to a digital input channel of the Gertbot and read the state (open or closed). I found already in the manual, that I need to set one of the unused pins of J3 as input, but I can't identify the pins and some lines of python commands would help to set and read the state of the input pin.
I connected already stepper motors with end switches and can control them, which was very nicely documented in the manual and the python example driver. This works perfectly.
Maybe anyone can give me a hint (the J3 pin numbering would already help a lot).
Greetings and thanks in advance!
Oliver
...in the meanwhile I found, that I can simply use some of the free GPIO pins of the Raspberry Pi. That makes it much easier and I might read them directly into my LabVIEW application (the programming frame of my application).
Greetings!
Oliver

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Gert van Loo
Posts: 2478
Joined: Tue Aug 02, 2011 7:27 am
Contact: Website

Re: Gertbot

Tue Nov 06, 2018 4:08 pm

The J3 pinout can be found in the GUI manual page 10. https://www.gertbot.com/gbdownload/man/Gertbot_GUI.pdf

Alternative is to start the GUI and after connecting press the 'board' button.

Example of using the inputs with Python can be found in the python_2.8a.tgz archive in the test program: test_drivers.py routine:
test_inputs (line 627).
https://www.gertbot.com/gbdownload/rev2 ... n_2.8a.tgz

olio
Posts: 17
Joined: Tue Feb 02, 2016 8:55 am

Re: Gertbot

Wed Nov 07, 2018 8:12 am

Good morning Gert,
thank you for the reply! In fact I didn't take a look into the GUI manual, because I never got this GUI running on my Pi...but I will use this manual as an additional source of information to the user manual of the board.

Yes, I found also the read inputs example in the test_drivers.py. But I didn't dare to connect anything, because I didn't know, which pins are usable for input and how to connect them.

The remaining free GPIO pins of the raspberry pi are accessible, the internal pull-up or -down resistors can be easily connected without any further external hardware with the channel setting and I can use them directly with LabVIEW.

Anyway I like your board very much and hope they will pass the first field tests, soon. I have currently three of them connected to one Pi for controlling some dosing systems of a "smart" water sampler.

Greetings and have a nice day!
Oliver

hapowelldavies
Posts: 2
Joined: Sun Dec 02, 2018 4:33 pm

Re: Gertbot

Sun Dec 02, 2018 6:10 pm

Hello Gert,

I am using two bipolar stepper motors connected to the Gertbot and a RPi 3 unit to control peristaltic pumps and I was wondering if it was possible to incorporate half-stepping and/or micro-stepping into the Gertbot code in order to get smoother transitions between steps especially using microstepping? I have been able to do this using an Adafruit HAT connected to the Pi so I was curious if the same is possible using the Gertbot and if so hwo I would go about gettign this to work?

Thank you in advance for your reply!

User avatar
Gert van Loo
Posts: 2478
Joined: Tue Aug 02, 2011 7:27 am
Contact: Website

Re: Gertbot

Tue Dec 04, 2018 1:00 pm

No, you can't do half or micro stepping. For that I would have to make major changes to the current software. As the sales of the product has reached its end-phase there is no return in that for me.

hapowelldavies
Posts: 2
Joined: Sun Dec 02, 2018 4:33 pm

Re: Gertbot

Tue Dec 04, 2018 1:44 pm

Ok that's understandable thank you for your reply. I was also wondering if it is possible to implement a timer in the code such that it starts when the stepper motor begins to rotate and ends when the rotation(s) finishes and calculates the time interval between this? If so how would I go about implementing this?

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Gert van Loo
Posts: 2478
Joined: Tue Aug 02, 2011 7:27 am
Contact: Website

Re: Gertbot

Wed Dec 05, 2018 9:21 am

Your question is somewhat confusing. You talk about a timer start & stop but then mention that it "calculates the time interval between this? " which is not what a timer function does.
You might have a look at section 7.25.2 of the manual Revision 2.8.
There is an signal called 'attention' which can be set to indicate that the stepper motors are not running. It goes to pin 22 of the Pi GPIO connector (See section 4.9.2). The signal is updated every millisecond so it is no instantaneous. It is an open collector line shared between cascaded gertbots, so it will indicate that all motors on all cards have stopped when it is high.
I'll be honest, I had forgotten about that function. I have not looked or tested it since the first version of the software so a new revision may have broken the functionality.

Manne
Posts: 1
Joined: Tue Dec 11, 2018 2:16 pm

Re: Gertbot

Tue Dec 11, 2018 9:19 pm

After a Long time I have reactivated my Gertbot succesfully with a Raspberry Pi 2 Model B and the actual Raspberry Strech Software :D .
Also the Gertbot Firmware upgrade from 2.3 to 2.8 was working well.

Thank you Gert I appreciate that you still support the Gertbot Software, Forum and Internet site.!

Do you have a hint how I can also get the Gui visible using the SSH ?

Kind regards

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Gert van Loo
Posts: 2478
Joined: Tue Aug 02, 2011 7:27 am
Contact: Website

Re: Gertbot

Wed Dec 12, 2018 8:16 am

The simplest solution would be to use VNC which, luckily for you, comes ready-packed with the Raspberry-Pi.

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