second hand cnc from 2007,could use help with pwm on odd control board
29 Nov 2022 13:08 - 29 Nov 2022 13:10 #257968
by andypugh
Do you know if these inputs are parallel-port compatible?
I will assume that the control board takes an enable and three binary bits.
There are several ways to control the bits. My natural instinct is to do it in HAL with converting the spindle speed commands to an integer with suitable scaling, and then pulling out the individual bits.
But in this case it might be better to use a G-code remap of the "S" command.
Read through the following first to decide if you prefer this to a HAL solution
There is far more docs here than you need so take this as "for reference only"
linuxcnc.org/docs/stable/html/remap/remap.html
However, you will need to carry out the steps in Section 4, including adding a [PYTHON] section to your
LinuxCNC G-code supports digital outputs which drive the HAL pins motion.digital-out-00 to -03 (and can be increased to -63)
You would need to connect these in HAL to parallel port output pins (do you have enough left?)
Then, every time LinuxCNC sees a "S" command in the G-code it will call the remapped subroutine below.
One reason to do it this way is that it allows you to customise the speed ranges and bit patterns easily.
In the INI, in the [RS274NGC] section add
Now create a file called "spindle.ngc" somewhere. I would suggest in the config folder (ie, the same folder as the INI). But that might need you to add "./" to the SUBROUTINE_PATH (also in the INI)
Initially, for testing, use this for your spindle.ngc
On balance, the HAL-only approach might actually be easier
Replied by andypugh on topic second hand cnc from 2007,could use help with pwm on odd control board
printer port. im not positive that it has to be done via pwm it has 4 speed inputs that can do start plus 7 speeds on the lower board.
Do you know if these inputs are parallel-port compatible?
I will assume that the control board takes an enable and three binary bits.
There are several ways to control the bits. My natural instinct is to do it in HAL with converting the spindle speed commands to an integer with suitable scaling, and then pulling out the individual bits.
But in this case it might be better to use a G-code remap of the "S" command.
Read through the following first to decide if you prefer this to a HAL solution
There is far more docs here than you need so take this as "for reference only"
linuxcnc.org/docs/stable/html/remap/remap.html
However, you will need to carry out the steps in Section 4, including adding a [PYTHON] section to your
LinuxCNC G-code supports digital outputs which drive the HAL pins motion.digital-out-00 to -03 (and can be increased to -63)
You would need to connect these in HAL to parallel port output pins (do you have enough left?)
Then, every time LinuxCNC sees a "S" command in the G-code it will call the remapped subroutine below.
One reason to do it this way is that it allows you to customise the speed ranges and bit patterns easily.
In the INI, in the [RS274NGC] section add
REMAP = S prolog=setspeed_prolog ngc=spindleNow create a file called "spindle.ngc" somewhere. I would suggest in the config folder (ie, the same folder as the INI). But that might need you to add "./" to the SUBROUTINE_PATH (also in the INI)
Initially, for testing, use this for your spindle.ngc
O<spindle> SUB
(debug, Entered spindle.ngc)
O100 IF [#<speed> GT 10000]
M64 P0
M64 P1
M64 P2
O100 ELSEIF [#<speed> GT 8000]
M64 P0
M64 P1
M65 P2
O100 ELSEIF [#<speed> GT 6000]
M64 P0
M65 P1
M64 P2
O100 ELSEIF [#<speed> GT 4000]
M64 P0
M65 P1
M65 P2
(more of the same)
O100 ELSE
M65 P0
M65 P1
M65 P2
O100 ENDIF
O<spindle> ENDSUB
M2On balance, the HAL-only approach might actually be easier
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