No stable connection between Canon 5DM4 and qDslrDashboard Galaxy Tab S6 Lite

qDslrDashbord error reports
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Posts: 3
Joined: 08 Jul 2021, 17:02

No stable connection between Canon 5DM4 and qDslrDashboard Galaxy Tab S6 Lite

Post by pdbgmuel »

My first post in this forum, hopefully not redundant.

My configuration:

qDslrDashboard V3.6.4 arm64
Tablet Samsung SM-P610 (Galaxy Tab S6 Lite)
Canon 5D Mark IV, Firmware V1.3.3
LRTimer 2.5, FW 27

I try to use the AutoHolyGrail functionality of qDslrDashboard using an external timer from G. Wegener. I connect the D5M4 to the tablet using to “access point mode” of the camera. I connect the tablet on Android level to the WiFi opened by the camera, open qDslrDashboard, connect to the camera, start AutoHolyGrail, start the external timer. The shooting starts as described. Live View is switch off, camera set to auto pwr off disabled, no captured picture displayed on camera LCD, tablet not in any energy saving mode.
qDslrDashboard tells after a while (sometimes only few shots, sometimes up to a 200+ shots) connection to camera lost. The WiFi symbol on the 5DM4 screen is blinking.
I have to terminate qDslrDashboard then. I can re-open qDslrDashboard on the tablet, reconnect to the camera and re-start AutoHolyGrail function from scratch. The WiFi connection is back again, there is no need on Android level to re-establish the WiFi connection! This is strange as the application detects a connection loss obviously caused by the target (5DM4), when the application is terminated the WiFi connections gets re-established automatically. Wired!

To eliminate potential WiFi weakness of the 5DM4 I set up a dedicated WLAN using a Huawei mobile router. The 5DM4 is a client on that network, same as the tablet. Same result as above, easy to hook up the tablet to the camera and get operation started. I tried Cell Phone and Tether mode on the camera. Result and behavior is exactly the same as above.

I have never seen these issues connecting camera and tablet directly using USB OTG cable. This mode of operation seems to work fine. Unfortunately, I consider WiFi connectivity way more flexible and preferable, especially when doing Holy Grail sessions outdoor.

Is anyone else having same or similar issues?
Is there a fundamental issue with 5DM4 WiFi implementation? Didn’t find a real hint to that.
Is here a chance that qDslrDashboard puts the camera into a mode that the WiFi connectivity suffers at the end?
Do I really have to switch to a high end/high cost solution like Tether Tools “Air Direct Wireless Tethering System”?

Any feedback is highly appreciated.



Posts: 3
Joined: 08 Jul 2021, 17:02

Re: No stable connection between Canon 5DM4 and qDslrDashboard Galaxy Tab S6 Lite

Post by pdbgmuel »

I coninued to have a deeper look into the issue. Here are my findings as of now.

Setting Tablet
Model Galaxy Tab S6 Lite
Android 12, UI 4.1, Patch April 2022

all energy savings off

all known networks set to "automatic reconnect disabled" EXCEPT
for the WLAN setup by Canon 5DM4 set to "automatic reconnect enabled"

all background apps stopped and killed

qDDBd version V3.6.8 for arm64

qDDBd configured as desired and described by GWegener, i.e.
- keep screen on: ON
- show capture history after capture: OFF
- image review after capture: OFF

while in qDDB holy grail mode of operation
- brightness turned down as much as possible

Setting environment
Canon 5DM4 hooked up by TetherTools Case Relay uninterruptable power source together with the Galaxy Tab to
- dual source Anker power bank
- dual source, dual 3.0A USB charger, 220V AC, wall outlet

5DM4 triggered by external Intervalometer, LRTimer V2.5, free running, unlimited shots, 25 sec interval

maximum spacing between Camera and tablet 60 feet

Camera setting

Camera Firmware 1.33
256 GB SD fast Card, 128 GB XD Card, RAW andJPG on same card
simple network set up by the camera
cell phone mode for the client
5DM4 indicates qDSLRDashboard as the app being coupled on app evel

picture format RAW + S3 JPG (default: RAW only, M1.1#1)
GPS OFF (default: M4.4#2 Modus 2, Log enabled)
Back View Time: Off (default 4 sec, M1.1#3)
Automatic Switch off: disabled (default:15 sec, M4.2#1)
Set Lens to MF by switch (default AF)
switch image stabilizer off by switch @lens (default on)


auto holy grail in sunset and sunrise mode work with NTC 2.0 for 1.5 h average before the first connection loss happens (shortest 45 min, 2h30 longest)
connection loss occurs only if WiFi symbol in camera display is starting to blink / flicker
WIFI connection between tablet and camera is reestablished (see above, is permitted only for this connection) but qDDB stays disconnected from the camera. qDDBd needs to be closed and restarted, holy grail mode of operation has to be reesatblished manually

to restart takes a minute typically. But you have to be aware that the connection loss happened. The audio notification does not work here any more (still no idea why)

viable work aroud and WASD?

Much better than before but I am not satisfied yet. I would expect stable and reliable operation for 4 h min.
I am still wondering if there is a crappy WIFI implementation on the Canon side or is qDDBd still facing app level timeouts under Android 12 that break the connection. I am wondering if I am alone and may see a specific issue on my 5DM4

Any feedback is highly appreciated



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Re: No stable connection between Canon 5DM4 and qDslrDashboard Galaxy Tab S6 Lite

Post by hubaiz »

Unfortunately I only have Canon 70D and Android 10 but will try to test this combination to see if I can eventually reproduce the problem.

Posts: 3
Joined: 08 Jul 2021, 17:02

Re: No stable connection between Canon 5DM4 and qDslrDashboard Galaxy Tab S6 Lite

Post by pdbgmuel »

Thanks a lot for your support.

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