Driving a charge pump with a Mesa 5i25 stepgen

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06 Feb 2022 21:38 #234177 by PCW
The quadrature output mode (mode 2) insures 50% duty cycle

(the step time and step space need to be set to small
values so they do not limit the step rate)

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06 Feb 2022 21:48 #234179 by dbotos
Ah, okay.

Am I missing some sort of virtual connection between the stepgen.04 output and pin 16 of the 5i25 DB25 connector (P3)?

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06 Feb 2022 21:55 #234180 by PCW
No, that should be in hardware

You can verify by looking at your current pinout with:

sudo mesaflash --device 5i25 --readhmid

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07 Feb 2022 00:10 - 07 Feb 2022 00:16 #234202 by dbotos
IO Connections for P3

Pin#  I/O   Pri. func    Sec. func       Chan      Pin func        Pin Dir

 1      0   IOPort       None           
14      1   IOPort       PWM              0        PWM             (Out)
 2      2   IOPort       StepGen          0        Step/Table1     (Out)
15      3   IOPort       None           
 3      4   IOPort       StepGen          0        Dir/Table2      (Out)
16      5   IOPort       StepGen          4        Step/Table1     (Out)
 4      6   IOPort       StepGen          1        Step/Table1     (Out)
17      7   IOPort       None           
 5      8   IOPort       StepGen          1        Dir/Table2      (Out)
 6      9   IOPort       StepGen          2        Step/Table1     (Out)
 7     10   IOPort       StepGen          2        Dir/Table2      (Out)
 8     11   IOPort       StepGen          3        Step/Table1     (Out)
 9     12   IOPort       StepGen          3        Dir/Table2      (Out)
10     13   IOPort       QCount           0        Quad-A          (In)
11     14   IOPort       QCount           0        Quad-B          (In)
12     15   IOPort       QCount           0        Quad-IDX        (In)
13     16   IOPort       None          

Looks like it's there.  What else could be preventing the waveform from getting output or the G540 from being able to recognize it?
Last edit: 07 Feb 2022 00:16 by dbotos.

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07 Feb 2022 02:35 #234214 by PCW
It may be that the chargepump output doesn't have enough
high level drive for the G540. You might try jumpering the 5I25
for 3.3V compatibility on P3, This will provide a bit more high side drive.

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07 Feb 2022 03:36 #234220 by dbotos
W3 jumper is in the UP position (5V tolerance mode enabled).  I had it that way when things were working under 2.5.3.  But I can give it a whirl tomorrow and see if it does anything.

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07 Feb 2022 14:30 #234247 by dbotos
No luck with the W3 jumper in the down position.

What to look at next?  Can I see what's going on with pin 16 output using HAL scope?  How is that done?  I've never used HAL scope before.

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07 Feb 2022 15:54 #234254 by PCW
I would set the frequency very low (say .25 Hz) and measure the
high and low output voltages on pin 16 with a voltmeter

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07 Feb 2022 17:32 #234261 by dbotos
I'll try that this evening and report back.

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07 Feb 2022 22:04 #234296 by dbotos
With the stepgen.04.velocity-cmd line in the HAL file set to 0.25, I'm not getting anything between pin 16 (charge pump) and pin 18 (GND) at my breakout board.

I looked at the x-enable signal in HAL scope and that was flat-lined.

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