Sovol's Eddy hardware info

Developers
1

Discord topic

So, it seems to be similar to the BTT Eddy coil, it is pure LDC1612 + Coil board.
Reference frequency is 12MHz.
Coil frequency according to dumps is ~8 385 484 Hz = 8.3 MHz
Coil size seems to be: 9.3mm x 5.5mm

Because 8.3MHz is way out of spec, it will require some Python side hacks at least.
Or, maybe not:

12_000_000 / (1 << 28) = 0.0447
8_385_484 / 0.0447 = 187580101
hex(187580101) = '0xb2e3ec5' # is < 0x03ffffff

Some reference configs:

[probe_eddy_current my_eddy_probe]
reg_drive_current: 20
PCB photos

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Calibration output with the current master F_IN_DIV = 2:

Frequency too noisy at step 1.810 -> 1.850
Frequency diff: 532.425, MAD_Hz: 244.914 -> MAD_Hz: 13.805
probe_eddy_current: noise 0.005354mm, MAD_Hz=115.202 in 1124 queries
Total frequency range: 39014.937 Hz
z_offset: 0.290 # noise 0.002908mm, MAD_Hz=90.512
z_offset: 0.530 # noise 0.003289mm, MAD_Hz=86.677
z_offset: 1.010 # noise 0.002055mm, MAD_Hz=49.632
The SAVE_CONFIG command will update the printer config file
and restart the printer.

With F_IN_DIV=4:

probe_eddy_current: noise 0.001774mm, MAD_Hz=21.036 in 2524 queries
Total frequency range: 59393.613 Hz
z_offset: 0.290 # noise 0.001932mm, MAD_Hz=59.151
z_offset: 0.530 # noise 0.001084mm, MAD_Hz=29.046
z_offset: 1.010 # noise 0.001801mm, MAD_Hz=38.516
z_offset: 2.010 # noise 0.001123mm, MAD_Hz=14.677
z_offset: 3.010 # noise 0.000231mm, MAD_Hz=1.931
The SAVE_CONFIG command will update the printer config file
and restart the printer.
Old Hack

So, hack for now is to change the value here: klipper/klippy/extras/ldc1612.py at master · Klipper3d/klipper · GitHub

- self.sensor_div = 1 if self.clock_freq != DEFAULT_LDC1612_FREQ else 2
+ self.sensor_div = 1 if self.clock_freq != DEFAULT_LDC1612_FREQ else 4

Hack is no longer required after v0.13.0-650-gca8230d50.

With F_IN_DIV=4 and reg_drive_current=21

probe_eddy_current: noise 0.001730mm, MAD_Hz=28.248 in 2524 queries
Total frequency range: 71648.040 Hz
z_offset: 0.290 # noise 0.002046mm, MAD_Hz=77.419
z_offset: 0.530 # noise 0.001592mm, MAD_Hz=55.797
z_offset: 1.010 # noise 0.003279mm, MAD_Hz=82.519
z_offset: 2.010 # noise 0.000826mm, MAD_Hz=11.995
z_offset: 3.010 # noise 0.003684mm, MAD_Hz=38.474
The SAVE_CONFIG command will update the printer config file
and restart the printer.

-Timofey

1 Like
Eddy: compensate bed_mesh with tap
2

Hey Timofey, thanks again for all the help!

With F_IN_DIV=4 and reg_drive_current=22

probe_eddy_current: noise 0.001387mm, MAD_Hz=28.688 in 2525 queries
Total frequency range: 87791.762 Hz
z_offset: 0.290 # noise 0.001456mm, MAD_Hz=69.981
z_offset: 0.530 # noise 0.000158mm, MAD_Hz=6.995
z_offset: 1.010 # noise 0.000772mm, MAD_Hz=23.503
z_offset: 2.010 # noise 0.001014mm, MAD_Hz=19.484
z_offset: 3.010 # noise 0.001115mm, MAD_Hz=13.904
The SAVE_CONFIG command will update the printer config file
and restart the printer.

Note that for reg_drive_current=21 and reg_drive_current=22 I had the bed at 60C during PROBE_EDDY_CURRENT_CALIBRATE

1 Like
3

edit: see github for latest updates:

4

Here is a better version of how to implement this, if anyone else would like to try:

please let me know if there are any issues, this was from memory, and of course as you know during testing things are done in all sorts of order

5

Hi there

I am looking at your github to see if it gives me any answers to problems that i am having “converting” my BTT Eddy from Eddy NG to native Klipper TAP. I have Klipper v0.13.0-729-gcab2f004. Downloading Scipy seemed sensible, so I did. Then I looked at ldc1612.py - there is no “else 2” at line 94 nor anywhere else in the file. Can I assume that my Klipper has changed the file?

6

Hi,

Hope that helps,
-Timofey

1 Like
7

Thank you.