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INDI Library v1.9.7 Released (29 Jul 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

USBFocusV3 jumps to zero, why ?

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Hi,
I have some strange problem. Sometimes when doing auto focus it goes allmost all the way to zero, a new control and now I see it goes from 64000 where it should be to 6000. Not very often but I had this problem at least three times.

I have the USB Focus V3. Astrobarry 204.

Good focus is around 63900, max position set in Ekos to 65000.

Anyone who has any idea why it doing like this ?

Include some screendumps

 

One of the focus point almost at zero but correct fous at 63900 where most focus points are..

 

Limit set to 6500. There are also two error messages:

"WARNING] Error reading response for command FPOSRO: Timeout error. "

"WARNING] Invalid response for command FPOSRO: missing cr+lf "

What does the command FPOSRO do ?

/Lars
TS130 APO & 3" field flattener / Pentax 645 ED 300mm f/4 /Sigma APO 150 mm f/2.8
EQ6 mount / HEQ5 / Star Adventurer
Canon EOS 6D
Lot of patience

Homepage:
www.astrofriend.eu/
Last edit: 6 months 3 weeks ago by Lars.
6 months 3 weeks ago #79432
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FPOSRO command is used to read the step count from the controller and it seems to get confused. If I remember correctly from working on the driver was that the controller handles step count as 16-bit value so the maximum step count is 65535 and then it would wrap to 0. Unfortunately there is no command to sync/set the step count to a lower value like many other controllers have so the only way to lower it is to run the focuser in a bit (to maybe 50000 or so) and then move the focuser out manually to the focus point so that the values when searching for focus are lower.

 
Remote observatory running Ubuntu 21.10 x64 with ScopeDome 2M, Skywatcher EQ8, TS 8" RC, Atik 383L+, ASI178MC, ASI120MM-S, SX Lodestar X2, SX USB wheel with OAG, ZWO EAF, Gemini SnapCap, USB_DewPoint, KomaHub
The following user(s) said Thank You: Lars
Last edit: 6 months 3 weeks ago by Jarno Paananen.
6 months 3 weeks ago #79447

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Hi Jarno,

Thanks for fast respons. I thought about the wraparound problem, but when I set the max position to 65000 I though it was impossible for it to wraparound. I use a camera lens and don't have much travel beyond the infinity, but still I can mechanically move the focuser so it ends at position 50000 or so. No need to go to lower focus positions.

Thanks a lot !

/Lars
TS130 APO & 3" field flattener / Pentax 645 ED 300mm f/4 /Sigma APO 150 mm f/2.8
EQ6 mount / HEQ5 / Star Adventurer
Canon EOS 6D
Lot of patience

Homepage:
www.astrofriend.eu/
6 months 3 weeks ago #79449

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Yes, thought the limits set to the controller would prevent that, but it doesn't seem to quite work... Unfortunately my USB_FocusV3 controller stopped working a bit over year ago so can't test that anymore. It would show up normally, but just didn't respond to any commands anymore.
Remote observatory running Ubuntu 21.10 x64 with ScopeDome 2M, Skywatcher EQ8, TS 8" RC, Atik 383L+, ASI178MC, ASI120MM-S, SX Lodestar X2, SX USB wheel with OAG, ZWO EAF, Gemini SnapCap, USB_DewPoint, KomaHub
6 months 3 weeks ago #79452

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That wasn't good, I'm satisfaid with my USB-Focus, but next time I build one myselfe, some Aurdino based. Tomorrow I adjust the focus range to 50'000 as you sugested.

/Lars
TS130 APO & 3" field flattener / Pentax 645 ED 300mm f/4 /Sigma APO 150 mm f/2.8
EQ6 mount / HEQ5 / Star Adventurer
Canon EOS 6D
Lot of patience

Homepage:
www.astrofriend.eu/
6 months 3 weeks ago #79454

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  • Posts: 107
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Today I offset my focus position counter. But didnt do it mechaniqucally, I moved to position 5000 and then reseted the counter. Now I have best focus at position 58900.

More details:

www.astrofriend.eu/astronomy/projects/pr...rs-raspberrypi4.html

Now I just have to do a test and see if the wraparound problem has disappear.

Thanks a lot jarno for the info !

Lars
TS130 APO & 3" field flattener / Pentax 645 ED 300mm f/4 /Sigma APO 150 mm f/2.8
EQ6 mount / HEQ5 / Star Adventurer
Canon EOS 6D
Lot of patience

Homepage:
www.astrofriend.eu/
6 months 3 weeks ago #79541

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