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Driving a ULN2003 Darlington array IC
24 Sep 2012 20:09 #24592
by liam2317
Driving a ULN2003 Darlington array IC was created by liam2317
Hello everyone,
I am a pretty big noob when it comes to CNC and LinuxCNC and am having trouble getting my system working.
What I have is a really basic two axis setup that I made myself from some old 5 wire stepper motors out of a printer. I would like to control them with a pair of ULN2003 Darlington array ICs (because they are amazingly cheap and I already have them). I have found a few sites/forum posts that say that this setup is possible with LinuxCNC and hint at how to do it but most of them are quite old and I can't get it working.
From what I understand I need to edit my .hal file and change stepgen from type 0 to type 5 as well as edit some other items in that file which will assign the proper output pin configuration. It also looks like I have to remove some items which only apply to type 0 but I can't figure out what. Is there an example .hal file for a type 5 stepgen anywhere? I have read the stepgen documentation but I am still lost.
The attached file shows how my configuration is wired.
Thanks for any help you can provide and sorry if this is in the wrong section!
-Liam
I am a pretty big noob when it comes to CNC and LinuxCNC and am having trouble getting my system working.
What I have is a really basic two axis setup that I made myself from some old 5 wire stepper motors out of a printer. I would like to control them with a pair of ULN2003 Darlington array ICs (because they are amazingly cheap and I already have them). I have found a few sites/forum posts that say that this setup is possible with LinuxCNC and hint at how to do it but most of them are quite old and I can't get it working.
From what I understand I need to edit my .hal file and change stepgen from type 0 to type 5 as well as edit some other items in that file which will assign the proper output pin configuration. It also looks like I have to remove some items which only apply to type 0 but I can't figure out what. Is there an example .hal file for a type 5 stepgen anywhere? I have read the stepgen documentation but I am still lost.
The attached file shows how my configuration is wired.
Thanks for any help you can provide and sorry if this is in the wrong section!
-Liam
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27 Sep 2012 19:50 - 27 Sep 2012 19:58 #24673
by liam2317
Replied by liam2317 on topic Re:Driving a ULN2003 Darlington array IC
Thanks for the help guys but I still can't quite get it working!
I have done a lot of reading and messing around with my .hal file but still have no output.
BigJohnT wrote:
I tried that but it doesn't generate any pins or anything. How else could I do this?
Anyway, my current .hal file loads fine, and when I go 'Machine > Show Hal Configuration' it looks to me like the pins and stepgen are set up properly. I have also tested my set-up by running it off an Arduino and can confirm that the ULN2003s and stepper motors are working properly. I also got some little breakout boards for the ULN chips that include LEDs so you can see when each pin is getting a signal, three pins on axis 0 are constantly lit and one on axis 1 but they do not change when the machine is jogged. Is there anything else other than my .hal file I need to configure?
At the moment I only have axis 0 and 1 connected to ULN2003s and mapped to parallel port pins but I would like to add the third axis in the future. Is it okay to leave it in the hal file as is or could the third axis be what is causing my problems?
Below is my .hal file and attached are some screenshots from my Show Hal Config page.
Any ideas what I'm doing wrong?? Thanks!!!
I have done a lot of reading and messing around with my .hal file but still have no output.
BigJohnT wrote:
I have not been able to figure out how to do this unless you mean running something like this in hal command: halcmd loadrt stepgen step_type=0,0,5 ctrl_type=p,p,vA far easier way is to return the first 3 back to type 0 and add one more as type 5 and see what pins are created for this and work from there.
I tried that but it doesn't generate any pins or anything. How else could I do this?
Anyway, my current .hal file loads fine, and when I go 'Machine > Show Hal Configuration' it looks to me like the pins and stepgen are set up properly. I have also tested my set-up by running it off an Arduino and can confirm that the ULN2003s and stepper motors are working properly. I also got some little breakout boards for the ULN chips that include LEDs so you can see when each pin is getting a signal, three pins on axis 0 are constantly lit and one on axis 1 but they do not change when the machine is jogged. Is there anything else other than my .hal file I need to configure?
At the moment I only have axis 0 and 1 connected to ULN2003s and mapped to parallel port pins but I would like to add the third axis in the future. Is it okay to leave it in the hal file as is or could the third axis be what is causing my problems?
Below is my .hal file and attached are some screenshots from my Show Hal Config page.
Any ideas what I'm doing wrong?? Thanks!!!
# Generated by stepconf at Mon Sep 24 10:57:34 2012
# If you make changes to this file, they will be
# overwritten when you run stepconf again
loadrt trivkins
loadrt [EMCMOT]EMCMOT base_period_nsec=[EMCMOT]BASE_PERIOD servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[TRAJ]AXES
loadrt probe_parport
loadrt hal_parport cfg="0x378 out "
setp parport.0.reset-time 5000
loadrt stepgen step_type=5,5,5 ###ctrl_type=v,v,v
## uncommenting ctrl_type makes no difference
addf parport.0.read base-thread
addf stepgen.make-pulses base-thread
addf parport.0.write base-thread
addf parport.0.reset base-thread
addf stepgen.capture-position servo-thread
addf motion-command-handler servo-thread
addf motion-controller servo-thread
addf stepgen.update-freq servo-thread
net spindle-cmd <= motion.spindle-speed-out
net xpa => parport.0.pin-02-out
setp parport.0.pin-02-out-reset 1
net xpb => parport.0.pin-03-out
setp parport.0.pin-03-out-reset 1
net xpc => parport.0.pin-04-out
setp parport.0.pin-04-out-reset 1
net xpd => parport.0.pin-05-out
setp parport.0.pin-05-out-reset 1
net ypa => parport.0.pin-06-out
setp parport.0.pin-06-out-reset 1
net ypb => parport.0.pin-07-out
setp parport.0.pin-07-out-reset 1
net ypc => parport.0.pin-08-out
setp parport.0.pin-08-out-reset 1
net ypd => parport.0.pin-09-out
setp parport.0.pin-09-out-reset 1
setp stepgen.0.position-scale [AXIS_0]SCALE
setp stepgen.0.steplen 200
#setp stepgen.0.stepspace 0
#setp stepgen.0.dirhold 35000
#setp stepgen.0.dirsetup 35000
setp stepgen.0.maxaccel [AXIS_0]STEPGEN_MAXACCEL
#net xpos-cmd axis.0.motor-pos-cmd => stepgen.0.position-cmd
#net xpos-fb stepgen.0.position-fb => axis.0.motor-pos-fb
net xpa <= stepgen.0.phase-A
net xpb <= stepgen.0.phase-B
net xpc <= stepgen.0.phase-C
net xpd <= stepgen.0.phase-D
setp stepgen.0.maxaccel 0.0
#net xstep <= stepgen.0.step
#net xdir <= stepgen.0.dir
net xenable axis.0.amp-enable-out => stepgen.0.enable
setp stepgen.1.position-scale [AXIS_1]SCALE
setp stepgen.1.steplen 200
#setp stepgen.1.stepspace 0
#setp stepgen.1.dirhold 35000
#setp stepgen.1.dirsetup 35000
setp stepgen.1.maxaccel [AXIS_1]STEPGEN_MAXACCEL
#net ypos-cmd axis.1.motor-pos-cmd => stepgen.1.position-cmd
#net ypos-fb stepgen.1.position-fb => axis.1.motor-pos-fb
net ypa <= stepgen.1.phase-A
net ypb <= stepgen.1.phase-B
net ypc <= stepgen.1.phase-C
net ypd <= stepgen.1.phase-D
setp stepgen.1.maxaccel 0.0
#net ystep <= stepgen.1.step
#net ydir <= stepgen.1.dir
net yenable axis.1.amp-enable-out => stepgen.1.enable
setp stepgen.2.position-scale [AXIS_2]SCALE
setp stepgen.2.steplen 200
#setp stepgen.2.stepspace 0
#setp stepgen.2.dirhold 35000
#setp stepgen.2.dirsetup 35000
setp stepgen.2.maxaccel [AXIS_2]STEPGEN_MAXACCEL
#net zpos-cmd axis.2.motor-pos-cmd => stepgen.2.position-cmd
#net zpos-fb stepgen.2.position-fb => axis.2.motor-pos-fb
net zpa <= stepgen.2.phase-A
net zpb <= stepgen.2.phase-B
net zpc <= stepgen.2.phase-C
net zpd <= stepgen.2.phase-D
setp stepgen.2.maxaccel 0.0
#net zstep <= stepgen.2.step
#net zdir <= stepgen.2.dir
net zenable axis.2.amp-enable-out => stepgen.2.enable
net estop-out <= iocontrol.0.user-enable-out
net estop-out => iocontrol.0.emc-enable-in
loadusr -W hal_manualtoolchange
net tool-change iocontrol.0.tool-change => hal_manualtoolchange.change
net tool-changed iocontrol.0.tool-changed <= hal_manualtoolchange.changed
net tool-number iocontrol.0.tool-prep-number => hal_manualtoolchange.number
net tool-prepare-loopback iocontrol.0.tool-prepare => iocontrol.0.tool-preparedPlease Log in or Create an account to join the conversation.
28 Sep 2012 04:13 #24679
by liam2317
Replied by liam2317 on topic Re:Driving a ULN2003 Darlington array IC
As far as I can tell doing that does absolutely nothing. Where should I be looking? What do I do after that? Running that hal file doesn't give an error but it doesn't make another axis show up or anything. Looking at it's Show Hal Config page doesn't give me any new info either.
Now I'm really confused....
Now I'm really confused....
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