zenointel-sd-2n-4g: run the pan/tilt head at 833 us per microstep

[widgetii]

Problem

The SD-2N-4G's /etc/gpiostep.conf steps the pan/tilt head at 2000/3000 µs per microstep, about 58 and 41 steps/s. Those values came from the stock config's motor blocks. Their timer 2 (pan) and timer 3 (tilt) are hardware timer numbers, not milliseconds, and the comment presented them as "the stock firmware's motor timers (2 ms pan, 3 ms tilt)".

The stock driver's own speed table runs the same motors at up to 1200 half-steps/s (833 µs). Two firmware changes now make that safe here:

• gpiostep: accelerate a move from rest, and hold the coils between moves firmware#2552: gpiostep.ko ramps every move up from rest.
• majestic-af: bump to cafc594 (motion seam, slow homing) firmware#2553: pins majestic-af with act_gpiostep: home slowly, however fast the head is set to run majestic-af#22, which homes at 2000/3000 µs whatever the running rate is, so the gearbox stops are never rammed at speed.

Change

pan_delay_us and tilt_delay_us become 833, and the comment says what the numbers are. Pan gets 2.4× faster, tilt 3.6×.

Hardware tested on

The device itself: GK7205V510 + MIS2009, Zenointel SD-2N-4G head. It ran the #2552 module and the #22 plugin, with these two values set in the camera's own /etc/gpiostep.conf. I did not flash an image built from this branch.

Evidence

Moves were 40 steps out and back, 3 cycles per run. Position was read back from the picture by phase correlation (about 4–5 px per step).

#2552 module, 833 us, single and 2-step-chunked moves, both axes: 12/12 runs, 0 px residual
#2552 module, 700 us: clean; 600 us: steps lost -> the motors' limit here is ~600-650 us
homing at a running delay of 833 us: 23-24 s (the slow rate's time), 3 homings within ~1.5 steps
pad moves through POST /ptz at 833 us: no lost steps over 4 runs (only the constant gearbox backlash)
measured rate through POST /ptz: ~136 steps/s pan

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PR Summary by Qodo

Increase SD-2N-4G pan and tilt cruising speed to 833 µs

⚙️ Configuration changes ✨ Enhancement 🕐 Less than 10 minutes

AI Description

• Set both pan and tilt cruising delays to 833 µs for faster movement.
• Clarify that movement ramps up from rest and homing retains its slower rate.

Diagram

graph TD
  A["gpiostep.conf"] --> B["majestic-af actuator"] --> C["gpiostep.ko"] --> D["Pan tilt motors"]

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High-Level Assessment

A device-local cruising-rate change is appropriate: it leaves the driver’s ramping behavior and the actuator’s slower homing behavior separate. Changing global driver defaults would affect other devices unnecessarily.

Files changed (1) +6 / -3

Other (1) +6 / -3

gpiostep.confSet both axes to 833 µs cruising delays +6/-3

Set both axes to 833 µs cruising delays

• Reduces pan delay from 2000 to 833 µs and tilt delay from 3000 to 833 µs. Replaces the misleading stock-timer comment with an explanation of cruising speed, driver ramping, and separate slow homing.

devices/gk7205v510_ultimate_zenointel-sd-2n-4g/general/overlay/etc/gpiostep.conf

[qodo-free-for-open-source-projects]

Code Review by Qodo

🐞 Bugs (0) 📘 Rule violations (0) 📎 Requirement gaps (0)

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Qodo reviewed your code and found no material issues that require review

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