Here's images with local lab bench lights off and on, judge for yourself.
I'm still not convinced your other 'scope is "brighter", just that it has more/bigger pixels illuminated on the trace.
(Yes, I'm aware that means there's more light coming out of it ... I'm just saying the Rigol's backlight isn't "dim" per se)
Also when booting, the large "RIGOL" shows up initially very bright and contrasty (nice!), then dims, then appears to brighten a little, then the screen appears and begins to dim again. The screen does seem to brighten some after warming up tho.
You may have a defective scope...
On my DHO804 the initial RIGOL logo starts bright, them dims and then brightens again.
With ADB you can change the brightness of the screen:
1> adb connect scope-ip-address:55555 [Connect via network]
2> adb shell settings get system screen_brightness [Returns 102. Range is 0-255)
3> adb shell settings put system screen_brightness 200 [This actually dims my screen, as explained below (*)]
4> adb shell settings put system screen_brightness 255 [This brightens the screen back to Max]
(*)The shell script that starts the scope (.../start_rigol_app.sh) seems to override the android system value (set to 102) to 255 via line 149 in the script:
echo 255 > /sys/devices/platform/backlight/backlight/brightness
I conjecture that the scope is bright at hardware/start-up, then the system dims it to 102, and then it gets reset by the Rigol start-up script to 255.
In my scope, omitting step 3> above, and setting it to 255 directly,
doesn't make the screen any brighter, consistent with my conjecture, in that:
(1) The start-up script seems to be overriding the system set value from 102 to 255.
(2) On my scope, the initial RIGOL splash screen starts bright, dims and returns to (and stays) bright, and the screen is as bright or brighter that any other instrument I have. (I also use a 22 inch hdmi monitor, which I have actually set dimmer than the scope screen.)
The value set in 3> or 4> above persists after a reboot. I have reset mine to 102, and still get the Max 255 brightness, as I have just described.
I just noticed a cool UI feature:
On the front of the 'scope there's two twisty knobs for moving things like cursors around.
In the setup dialogs there's two little indicators to show you that some values can be adjusted using the knobs, eg. Here I can change the Bias voltage using knob 1 and knob 2 changes the channel offset.
What I just noticed is that the indicators move around if you touch the input boxes. eg. If I touch "Scale" then "Skew" they change to this:
While you might be correct technically about sending ADB commands, if you read Mike's post, you will realize he didn't buy scope to play with it.
While you might be correct technically about sending ADB commands, if you read Mike's post, you will realize he didn't buy scope to play with it.
If you read my post you will realize that my scope did not have a brightness problem out of the box.
"Also when booting, the large "RIGOL" shows up initially very bright and contrasty (nice!)" (as Mike puts it) is where my scope brightness ends up, by default, as it did out of the box. The adb commands and the rest of my post were used to explain why that may be the case.
Another happy user (oscope in action - tube amp?)..
Also when booting, the large "RIGOL" shows up initially very bright and contrasty (nice!), then dims, then appears to brighten a little, then the screen appears and begins to dim again. The screen does seem to brighten some after warming up tho.
You may have a defective scope...
On my DHO804 the initial RIGOL logo starts bright, them dims and then brightens again.
With ADB you can change the brightness of the screen:
1> adb connect scope-ip-address:55555 [Connect via network]
2> adb shell settings get system screen_brightness [Returns 102. Range is 0-255)
3> adb shell settings put system screen_brightness 200 [This actually dims my screen, as explained below (*)]
4> adb shell settings put system screen_brightness 255 [This brightens the screen back to Max]
(*)The shell script that starts the scope (.../start_rigol_app.sh) seems to override the android system value (set to 102) to 255 via line 149 in the script:
echo 255 > /sys/devices/platform/backlight/backlight/brightness
I conjecture that the scope is bright at hardware/start-up, then the system dims it to 102, and then it gets reset by the Rigol start-up script to 255.
In my scope, omitting step 3> above, and setting it to 255 directly,
doesn't make the screen any brighter, consistent with my conjecture, in that:
(1) The start-up script seems to be overriding the system set value from 102 to 255.
(2) On my scope, the initial RIGOL splash screen starts bright, dims and returns to (and stays) bright, and the screen is as bright or brighter that any other instrument I have. (I also use a 22 inch hdmi monitor, which I have actually set dimmer than the scope screen.)
The value set in 3> or 4> above persists after a reboot. I have reset mine to 102, and still get the Max 255 brightness, as I have just described.
Here's images with local lab bench lights off and on, judge for yourself.
I'm still not convinced your other 'scope is "brighter", just that it has more/bigger pixels illuminated on the trace.
(Yes, I'm aware that means there's more light coming out of it ... I'm just saying the Rigol's backlight isn't "dim" per se)
Arguing semantics is what lawyers do.
And you just explained yourself what the problem is.
Monitors are specified in nits, one candela per square meter (cd/m2).
Not per pixel.
Small screen and small pixels means less radiated optical power from single pixel. So if you make a small text, that text radiates with small amount of surface.. Makes it less luminous... It can have good contrast up close but it will be less visible from distance.
And it DOES seem to be really shiny and reflective, which does not help.
If screen is not good enough, people should complain to Rigol so they fix it. They did it for MSO5000. If you keep quiet and trying to shut up other people complaining they'll keep suboptimal screen and nobody profits from it.
Maybe it is only some software setting.
I honestly did not understand that from your post... But thank you for explaining.
And your explanation show you understand a great deal about how it works..
But as I said, there are many of us that won't thinker with it (lack of certain type of skills, time etc) but expect it work from the box...
This is one of the things that sure look (after your explanation) that Rigol could "fix" with correct config in software in one of the updates....
Nice video, note display here.
https://youtu.be/3OJnjXrAf5k?t=270
Here it is next to my Micsig. The Micsig is at full brightness.
---
I'm waiting on a couple of screen protectors to try with my Rigol.
it does look like you have some kind of screen protector on it, as your screen also has air bubbles. (we've all been there, they are a high-maintenance b to squeeze out)
FWIW: If you tell your DHO to go to the Android home screen (via ADB) all you get is the same black background with "Rigol" that you see during power on.
There's no icons or menus or anything like that.
It doesn't respond to any inputs, you have to power it off and restart.
FWIW: If you tell your DHO to go to the Android home screen (via ADB) all you get is the same black background with "Rigol" that you see during power on.
There's no icons or menus or anything like that.
It doesn't respond to any inputs, you have to power it off and restart.
I wonder if you can `adb install` some launcher apk to get a decent home screen?
Analogue / Digital / Max Sample rate / Max mem depth/channel
0 / 1 to 16 / 625MSa/s / 25Mpts
1 / 0 / 1.25GSa/s / 50Mpts
1 / 1 to 16 / 625MSa/s / 25Mpts
2 / 0 / 625MSa/s / 25Mpts
2 / 1 to 16 / 312.5MSa/s / 10Mpts
3 or 4 / 0 / 312.5MSa/s / 10Mpts
3 or 4 / 1 to 16 / 156.25MSa/s / 1Mpts
Something also of note is that when you add the LA, the sample rate is halved again, so if you run 3 or four analogue channels and any number of LA channels. the maximum sample rate drops to 156.25MSa/s. Whether the trigger is on an analogue or digital channel didn't affect the maximum sample rate.
Something also of note is that when you add the LA, the sample rate is halved again, so if you run 3 or four analogue channels and any number of LA channels. the maximum sample rate drops to 156.25MSa/s. Whether the trigger is on an analogue or digital channel didn't affect the maximum sample rate.
That's a bummer -- both, the sample rate restriction.....
Something also of note is that when you add the LA, the sample rate is halved again, so if you run 3 or four analogue channels and any number of LA channels. the maximum sample rate drops to 156.25MSa/s. Whether the trigger is on an analogue or digital channel didn't affect the maximum sample rate.
That's a bummer -- both, the sample rate restriction and falling back to the measly 1 Mpt memory. I can't find these limitations mentioned at all in the DHO 900 datasheet.
In a mixed-signal scope, I expect to be able to observe a "mix" of digital and analog inputs without incurring an extra penalty. Disappointing, and probably the finding so far which detracts me most from a DHO900. Is that a compromise made in other mixed-signal scopes too?
..As a side note, we can probably give up on the hope that someone will come up with a hack to upgrade the DHO 800/900 to the 2 GSa/s sample rate of its larger sibling. Looks like the FPGA is already running at capacity and is limiting the total data rate?
Something also of note is that when you add the LA, the sample rate is halved again, so if you run 3 or four analogue channels and any number of LA channels. the maximum sample rate drops to 156.25MSa/s. Whether the trigger is on an analogue or digital channel didn't affect the maximum sample rate.
That's a bummer -- both, the sample rate restriction.....
I agree. Honestly, the scope is great value but after reading first user reports here I pass and go for a different option.