×
INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

DIY focuser w/o Motor HAT or PiFace?

2 years 11 months ago
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19012
Hi Helge, thanks a lot!
So I need to get myself PiFace Digital 2, right? Can it handle two motors in parallel (I plan to have for the guider scope, too)?

Maurizio

Please Log in or Create an account to join the conversation.

2 years 11 months ago
TallFurryMan
Platinum Boarder
Platinum Boarder
Posts: 899
Karma: 13
More
DIY focuser w/o Motor HAT or PiFace? #19013
I also made a 3D-printed focuser using the BYJ reference you mentioned. Works great because the angle step matches nicely the micro knob of my ED80T. However there's a consequent backlash on that stepper reference, which often makes Ekos slow down searching for the HFR minimum. But while the gaussian fit isn't that efficient because of that, the iterative method works pretty well. Being new at CAD design, I'm very proud of that first result :)

-Eric

Envoyé de mon ASUS_Z00AD en utilisant Tapatalk

HEQ5-Pro - Atik 314E - Orion ED80T - DMK21 on Orion 50mm
DIY 3D-printed Moonlite and FWheel RGB/LPR
KStars and indiserver on two Atom 1.6GHz 1GB RAM Linux, VPN remote access

Please Log in or Create an account to join the conversation.

2 years 11 months ago
HelgeMK
Gold Boarder
Gold Boarder
Posts: 307
Karma: 1
More
DIY focuser w/o Motor HAT or PiFace? #19014
Hi Maurizio,

In principle, the script makes provisions for two steppers, but for the PiFace digital2, the second routine ends up on the Input Pins of the PiFace digital (I think the script was not written for that version of the PiFace - @ Radek, hope I am not mistaken).

The first stepper is on the output pins 4-7, ideally the second stepper could be run on output pins 0-3, but I am lacking of programming skills to re-direct the routing from the input- to the output pins.

Best, Helge

Please Log in or Create an account to join the conversation.

2 years 11 months ago
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19015
Dear Helge,
if I understand correctly, I must load the astroberry-piface driver, right? Can you confirm that it supports the PiFace Digital 2? My RPi3 runs on Ubuntu Mate, but as I read here ( http://indilib.org/forum/general/699-astroberry-initial-release.html?start=24 ) it may not work on Ubuntu Mate.

Please Log in or Create an account to join the conversation.

2 years 11 months ago
HelgeMK
Gold Boarder
Gold Boarder
Posts: 307
Karma: 1
More
DIY focuser w/o Motor HAT or PiFace? #19022
Dear Maurizio,

I am using the "astroberry server", see www.indilib.org/forum/general/2183-astroberry-server/16419.html - which is fantastic. I think it is based on Ubuntu Mate.

It already has the PiFace focuser-driver on board. In a previous post, Radek mentioned that he might also onboard the "astroberry focuser" in a future release, so you could alternatively connect the stepper via a driver board to the Raspberry.

If you are interested, this focuser via arduino nano hansastro.github.io/Focuser/

is also a nice way to manage the focuser, with a 12v bipolar stepper, which has a little bit more torque than the 28byj48 stepper (which I started with).

Best, Helge

Please Log in or Create an account to join the conversation.

2 years 11 months ago 2 years 11 months ago by Kaczorek.
Kaczorek
Moderator
Moderator
Posts: 901
Karma: 6
More
DIY focuser w/o Motor HAT or PiFace? #19041

HelgeMK wrote: ...the script was not written for that version of the PiFace - @ Radek, hope I am not mistaken


This is correct. It was originally written for the first revision of PiFace board. I think I will need to release another version for PiFace Digital so the second focuser is available.

Radek

--
Radek Kaczorek
Astroberry Server | NEQ6 | Atik 460EX | Atik EFW2 | ASI 120MM

Please Log in or Create an account to join the conversation.

2 years 10 months ago
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19076
I've been busy trying to get myself a PiFace Digital 2 but no luck, these little things seem to disappear faster than they are supplied. Should definitely get one asap. In the meantime I have received a Nema17 motor and a4988 driver board. I have tried to connect the board to the RPi3 as per instructions in INDI Astroberry website, but no luck. When I load the indi_rpifocus driver in indiserver, no Astroberry Focuser tab will show up in Ekos. I have installed INDI Astroberry from the .deb file at https://sourceforge.net/projects/astroberry/ . Any idea why it's not working?

Maurizio

Please Log in or Create an account to join the conversation.

2 years 10 months ago
HelgeMK
Gold Boarder
Gold Boarder
Posts: 307
Karma: 1
More
DIY focuser w/o Motor HAT or PiFace? #19079
Dear Maurizio,

I am sure you double-checked the stepper pins etc already? Whenever testing a new stepper (and nothing happened), it was the pins. Another cause of errror could be the current control VREF, to limit the current. Does all this match your power supply and stepper?

I also wanted to test the rpi_focuser, but struggling to install - see my other post.

Best, Helge

Please Log in or Create an account to join the conversation.

2 years 10 months ago
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19101
I am going to double check all connections with a multimeter then. One thing that is not clear to me is if I should connect the RESET pin with the SLEEP pin, which is in turn connected to GPIO23 on the RPi3. It does not say anything on the Readme file ( https://github.com/rkaczorek/astroberry-diy/blob/master/README ), but it is usually connected as shown in many other images on Google (see here ).

Regarding Vref, it should be measured between the GDN pin powering the board and the top of the potentiometer, right? The Nema 17 has a nominal current limit of 1.5 A monophase (does it mean "per coil"?). What value should Vref be set to? 3 V?

Do I need to power the motor via Vmot (nominal tension 3.45 V) or is the board powering it via Vdd?

Sorry for all these questions, which you might find stupid or obvious, but this is the first time I deal with stepper motors.

Maurizio

Please Log in or Create an account to join the conversation.

2 years 10 months ago
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19107
I have double checked all connections and they're alright. This is what I get when I load indi_rpifocus in indiserver:
2017-09-05T17:29:58: Driver indi_gphoto_ccd: pid=2008 rfd=3 wfd=6 efd=7
2017-09-05T17:29:58: Driver indi_asi_ccd: pid=2009 rfd=4 wfd=9 efd=10
2017-09-05T17:29:58: Driver indi_lx200autostar: pid=2010 rfd=5 wfd=12 efd=13
2017-09-05T17:29:58: Driver indi_rpifocus: pid=2011 rfd=8 wfd=15 efd=16
2017-09-05T17:29:58: listening to port 7624 on fd 11

What could the problem be? Could it be that my Ekos client (running on my Mac) does not recognize the driver? I am still puzzled by the SLEEP-RESET connection dilemma.

Please Log in or Create an account to join the conversation.

2 years 10 months ago 2 years 10 months ago by m.baldassarre.85.
m.baldassarre.85
Junior Boarder
Junior Boarder
Posts: 23
More
Topic Author
DIY focuser w/o Motor HAT or PiFace? #19109
I finally got to load the indi_rpifocus driver, I had to recompile the drivers from source. I get the Astroberry Focuser tab in my Ekos client. I still DO NOT manage to get the motor going. Could anyone who has managed to get the a4988 board working tell me which pins of the board should be connected to?

What port should be used? Default is /dev/ttyUSB0 but that looks wrong.

Thanks!

Please Log in or Create an account to join the conversation.

2 years 10 months ago 2 years 10 months ago by Kaczorek.
Kaczorek
Moderator
Moderator
Posts: 901
Karma: 6
More
DIY focuser w/o Motor HAT or PiFace? #19113
First of all (as per A4988 datasheet) - RESET turns off all of the FET outputs. All STEP inputs are ignored until the RESET input is set to high. This means that connecting it to SLEEP will set it to high state and will enable outputs.
Now, ENABLE turns on or off all of the FET outputs. When set to a logic high, the outputs are disabled. This means you need to make sure that it is set to low state.
Take a look at this image to connect the A4988 controller to RPi pins.

Make sure that GPIO pins are connected to proper pins at A4988 i.e. GPIO04 - DIR, GPIO17 - STEP, GPIO22 - M0, GPIO27 - M1, GPIO23 - SLEEP (BTW. please note that GPIO number is not the same as pin number e.g. GPIO04 is pin 7 and GPIO17 is pin 11 etc.) - see the pinout below.

--
Radek Kaczorek
Astroberry Server | NEQ6 | Atik 460EX | Atik EFW2 | ASI 120MM

Please Log in or Create an account to join the conversation.

Time to create page: 0.581 seconds