Spindle PWM settings

[karoria]

Hi friends, I am using a delta MS300 VFD with 0-10V analog input. I use a pwm to analog converter board for this whhich is readily available in market. I am not getting proper rpm when vfd input voltage is near to zero. So, I have decided to use 3 to 10 V analog to map with 0 to 24000rpm of my 2.2kw spindle. The setting for vfd is already done, but I can't figure out how to set spindle pwm to range from 30% to 100% duty cycle. I want to map 30% duty cycle as 0 rpm and 100% as 24000rpm. I tried $35 =30 and $36 =100 but no luck. Please guide me.

[bdring]

Try setting your values like this...

$30=24000.000
$31=0.000
$32=0
$33=5000.000
$34=0.000
$35=30.000
$36=100.000

Then do a reboot by either clicking the reset button on the ESP32 or sending [ESP444]RESTART.

It works for me on my test system.

[karoria]

Thanks a lot. Will try today only.

[karoria]

It seems there is a bug. I tried with two type of settings and the results were different. I used DSO to measure duty cycle. Following are settings:

Common settings: $30=24000.000 $31=0.000 $32=0 $33=5000.000 $34=0.000

Case 1: $35=30.000 $36=100.000 Measurements of spindle rpm sent via gcode Vs PWM Duty Cycle 10-12% 1000-14.5% 12000-46.5% 23000-78.4% 24000-99.5%

Case 2: $35=60.000 $36=100.000 Measurements of spindle rpm sent via gcode Vs PWM Duty Cycle 10-23.5% 1000-25% 12000-43% 23000-61% 24000-99.5%

My observation from the above readings: say total blank span out of 100%= 30 in first case and 60 in second case. name it 3x. So the duty cycle before spindle min rpm shall be x and after max rpm shall be 2x. Strange thing is at 23999 rpm the duty cycle remains 80% for first case and at 24000 it becomes 99.5% (theoretically 100%).

I hope this data might be useful and I am able to explain it well. Waiting for prompt response.

[bdring]

I am not sure why you are having trouble. This is my test with results read from a logic analyzer.

0 = 0% 1 = 30% 1000 = 33% 12000 = 65% 23000 = 97.50% 24000 = 100%

S12000 Example

The math is quite simple. It uses a classic map function as described here.

Before the map function it applies any speed overrides and makes sure you are in the min/max range.

[karoria]

I use pin 17 for spindle pwm. I don't use RMT steps. Does it have any connection to this problem? I suspect there is something in firmware to be enabled or disabled before compiling, which I use differently then you.

[karoria]

OK. I found the Fix. It is those last 11 #define lines of config.h file which are active (not commented out) by default although you are not using piecewise linear spindle. I recommend to comment out those lines by default. Thanks for time :)

[karoria]

Reopening. Sorry, I messed up two different folders of code. That was not actual fix. Now I observe that "disabling limit pin pullup" causes the pwm output behave like those readings above. I use inverse logic limit switches and for that I use external pulldown resistors. I can't figure out how a limit switch pullup can cause malfunction in spindle pwm output. This happens in latest firmware as well as some 6 months old firmware.

[bdring]

Can you paste your complete machine definition file here?

[karoria]

Sure. I am out of station for 2 days. Will paste it when back to work.

[karoria]

Sorry for long delay in submitting my machine definition file. Actually I was struggling to reproduce the same as I use inverse type settings in my machine PCB for limit switches. Most of the time I check the ESP32 Dev board unattached, I face problems of false triggering hard limits, door alarm etc. Now I am attaching config.h, cpu_map.h and defaults.h files which are as per old firmware. I am also struggling to get new firmware up and running as when I give M3 command, machine alarms for hard limit. First thing first, I would highly appreciate getting a solution of the problem defined in this thread. I know this might take a good time of your efforts and thank you very much in advance for all that. Waiting for any clues... karoria_config.zip

[bdring]

Could you please also paste your startup messages. I would like to know what version you are running.

[karoria]

[ESP444]RESTART [MSG:Restart ongoing] ok ets Jun 8 2016 00:22:57 rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT) configsip: 0, SPIWP:0xee clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00 mode:DIO, clock div:1 load:0x3fff0018,len:4 load:0x3fff001c,len:1216 ho 0 tail 12 room 4 load:0x40078000,len:9720 ho 0 tail 12 room 4 load:0x40080400,len:6352 entry 0x400806b8 [MSG:Axis count 3] [MSG:Timed Steps] [Controller:ENGILABS_V4] Grbl 1.1f ['$' for help] [MSG:Check Limits] [MSG:'$H'|'$X' to unlock]

Where I replaced CPU_MAP_ESP32_V3.5 to ENGILABS_V4 in my file. I don't use any wifi/bluetooth/telnet/sd features and all are disabled in config.h

[bdring]

That is a very old version of Grbl_ESP32. Many issues have been fixed since then.

Please use the current version of the master or devt branches. We can provide support on those versions.

[karoria]

Ok. I have some issues in latest master too. I will re-try that and update you.