Some days ago I start to use a BT mouse. Sometimes its work fine and other times have lag.
After try to check what causes this, and ran several monitoring tools and notice if RSSI is 0 its works fine... but when it decreases, the lag got worst, and lower the RSSI value, worst is the lag.
Because I work in office with lots of wireless equipment, probably with Adaptive Frequency Hooping sometimes it get non clean environment, or the frequency hooping is not working as it should, and not changing to a cleaner frequency.
It is possible, in Linux, to the connection with mouse get stuck to a specific channel/frequency when I manually found one clener?
There is any tool which I can get the channel/frequency the connection is using?
Regards,
Filipe
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I am trying to build an Android app that interfaces with the ESP32 using BLE. I am using the RxBluetoothKotlin library from Vincent Masselis for the Android side. For the ESP32 side, I am using the default Kolban libraries that are included in the Arduino IDE. My phone is a OnePlus 5T and my ESP32 is a MH ET Live ESP32DevKIT. My Android app can be found here, and my ESP32 program here.
The whole system works pretty much perfectly for me in terms of pure functionality. That is to say, every button does what it's supposed to do, and I get the exact behaviour I had expected to get. However, the communication itself is very slow. Around 200 bytes/second. My test button in the Android app requests a bunch of text data from the ESP32, and displays this in a dialog. It also lists a number which represents the time between request and reception in milliseconds. Using this, I get around 2 seconds for 440 bytes of data. When I send less data, the time decreases approximately linearly with data size. 40 bytes of data will take around 200ms, and 20 bytes or under typically takes less than 100ms.
This seems rather slow to me. From what I understand, I should be able to at least get a few kilobytes per second. I have tried to check the speed using nRF Connect, but I get the same 2 seconds timespan for my data transfer. This suggests that the problem is not in my app, since I also have it with a completely different app. I also put the code in my main loop inside of callbacks instead (which I probably should have done in the first place), but this didn't change things at all. I have tried taking the microcontroller and my phone to a few different locations, hoping to eliminate interference. I have tried to mess with BLEDevice::setPower and BLEDevice::setMTU, as well as setting RxBluetoothGatt.requestMtu(500) on the Android side. Everything so far seems to have had little to no effect. The only thing that did anything, was adding the line "pServer->updatePeerMTU(0,500);" in my loop during the connection phase. This caused the first 23 bytes of data to be repeated whenever I pressed the test button in my app, and made the data transfer take about 3 seconds. If I'm lucky, I can get maybe a bit under 1.8 seconds for 440 bytes, but this is a very small change when I'm expecting an order of magnitude of difference, and might even be down to pure chance rather than anything I did.
Does anyone have an idea of how to increase my transfer speed?
The data transmission speed is mainly influenced by the Bluetooth LE connection interval (between 7.5 ms and 4 seconds) and is negotiated between the master (central unit) and the peripheral device. The master establishes a connection with a parameter set and the peripheral can propose to change this parameter set. In the end, however, the central unit decides which parameter set is to be used.
But the Bluetooth connection interval cannot be changed by an Android applications directly, which normally act as the central role. Instead it can request a connection priority which is known to have an influence on the connection interval.
I have a bluetooth keyboard that I use on a regular basis. It has a Logitech logo, but is manufactured by ZAGG and has model number Y-R0023.
I have paired the keyboard with my Ubuntu desktop and it works great.
Upon powering up my computer and keyboard, I can sometimes reconnect without having to pair again, but other times I have to remove the existing pairing and reconnect before Ubuntu can receive keystrokes.
Extra information: Ubuntu displays a bluetooth symbol as a status when it connects (regardless if it is able to receive keystrokes or not). This symbol will appear and disappear roughly every 10 seconds until the two devices are able to successfully negotiate a valid connection.
I notice that I have best success when I press 'delete-delete-enter-enter' after powering the ZAGG keyboard up. (Sometimes, just repeatedly pressing a key every second or so seems to work too.)
I am wondering if the "delete-delete-enter" keystroke combination (or some other that I haven't discovered) is recognized by the Logitech BIOS as a special sequence to help retry a paired re-connection. I'd be interested in finding out if this trick works for devices other than those made by ZAGG. Otherwise, it would help just to know if there is a reliable script I can run that calls bluetoothctl to help improve the re-connection. (I want to avoid having to enter a pairing code on subsequent connections).
ZAGG sites and Logitech ones don't say anything about this key combination. So I don't think it's recognized as a special sequence, only advice they give is to re-pair the device when it's not working.
In summary I'm sure they would include this troubleshooting option in manual and/or troubleshooting guide if it was present.
I'm working on some home automation programs and one of the things I want to be able to do is detect when my 4th generation Apple TV has woken from sleep. This will generally only ever happen when someone pressed a button on its Siri remote to wake it up.
I have a PC (connected to the same TV as the Apple TV) that has a Pulse-Eight USB-CEC adapter, so naturally the first thing I tried was using CEC to determine when the Apple TV is awake. Unfortunately it's not reliable, since monitoring the Apple TV's power status to see when it wakes up produces false positives. (I should note that I do not have "Control TVs and Receivers" enabled on the Apple TV, and can't turn it on for the particular project I'm working on because I need the Apple TV to not change the TV's input.)
I'm trying to think of some other way to do this. I'm open to any possibilities, including things like:
Making use of private APIs on the Apple TV
Running an 'always on' program in the background of the Apple TV that sends a signal when the Apple TV wakes up, if that's even possible. (I suspect that it isn't.)
Monitoring the bluetooth communication between the Siri Remote and the Apple TV, if that's possible
Somehow filtering HDMI-CEC commands so that I can turn on 'Control TVs and Receivers', allow the Apple TV's CEC commands for turning on and off the TV, and exclude commands for changing the TV's input.
Any other method, no matter how hacky or ridiculous, as long as it works!
Does anyone have any suggestions? I'm running out of things to try!
I tried to post below on apple discussion / support communities but was told i don't have the right to post this content. Maybe someone in this group can succeed in doing it:
Apple TV 4 CEC integration is great when it works, but it doesn't work all the time and not with all the various equipment out there, you can do a search across forums and you will see lots of unhappy users. I would like to use a raspberry PI to detect when my AppleTV goes to sleep and wakes up and programmatically turn my tv on or off using its RS232C or custom CEC commands.
I used a bonjour services explorer and compared every single result between sleep and on states and there are no differences whatsoever. I would have expected Apple to welcome such automation projects and make this information readily available with a variable such as status: sleep or status: on.
Is there a way I could tell the two states apart via the network connection?
If not, could one build a TvOS app which runs on the background and makes this information available to clients somehow?
I finally found a method that seems to work consistently. This method is incredibly hacky and not at all the sort of way I'd prefer to do this, but it's the only one I've found so far that works consistently.
I have taken an old USB webcam and affixed it to the front of my Apple TV so that its lens is directly in front of the Apply TV's front facing light. Whenever the Apple TV is asleep, I simply check for the light turning on by taking images from the camera and analyzing their average luminosity. Since the lens is right next to the light, when it turns on it'll create a huge blown out white circle in the image that's incredibly easy to detect.
As long as the Apple TV is asleep, the light turning on seems to indicate 100% of the time that it has woken up. I have yet to find a single incident of either a false positive or false negative.
Since pressing buttons on the Siri remote causes this light to blink, this also means that I can detect buttons being pressed by looking for changes in the light while the Apple TV is awake. It's not 100% accurate, since some button presses are faster than the frame rate of my crappy old USB webcam, but it works well enough.
I would vastly prefer to find a better method of doing this, like making a request over the LAN to the Apple TV where the response clearly indicates it being awake or asleep, but so far it doesn't look like that's possible.
Here I am, six and a half years later, and I've finally found a better way to get the power state of my Apple TV.
I can simply use pyatv, which has a function named power_state that returns the Apple TV's current power state.
I just picked up the Lenovo Thinkpad Yoga 15 (20DQ001KUS) for $799. Here is a link: http://shop.lenovo.com/us/en/laptops/thinkpad/yoga-series/yoga-15/#tab-tech_specs
I'd really like to get the tablet features working in Linux Mint 17.2. I have been doing some googling and found some old scripts below:
https://github.com/admiralakber/thinkpad-yoga-scripts
https://launchpad.net/magick-rotation
With their help, I was able to put together a python script that polls my accelerometer values (found in /sys/bus/iio/devices/iio:device*) to figure out when the screen should be rotated. The difficult part seems to be detecting when the device should be in laptop or tablet mode. If I bend the lid past 180 degrees, or if I tilt the device on its side so that it is perpendicular to the ground, there is a light on my keyboard that shuts off and the keyboard itself is completely disabled. This appears to be a bios feature and indicates that there is definitely a sensor. This would be ideal, and it would solve all of my current problems.
Unfortunately, I have been unable to find any sensor readout in linux that would tell me when the computer should be in tablet mode. I need this to determine when autorotate should be turned on, when the touchpad/trackpad/keyboard should be disabled, and when I should launch or kill the onscreen keyboard app.
In the meantime, I'm using the lid's incline sensor (also found in /sys/bus/iio/devices/iio:device*). This works mostly, as It can detect tent mode and tablet mode. Unfortunately, the sensor is aligned to gravity, so it cannot tell the difference between laptop mode and stand mode (because the lid/screen is in the same orientation with respect to gravity).
The older scripts suggest that there is a special keycode in older models that is triggered when the mode changes from laptop to tablet and vice-versa. Unfortunately, I am not seeing any such keycode/scancode being thrown when I monitor xev/evtest.
In short, I'd like to be able to programmatically determine when the laptop screen/lid is opened more than 180 degrees. Can anyone help me with this?
My current script is linked below, if anyone else wants to see how I'm doing it (or if anyone else wants to make suggestions), I've only spent a day on it, so it's nowhere near finished. I'll probably publish it for GNU release at some later point in time for anyone else needing the same functionality.
https://gist.github.com/anonymous/5d2c2d2967eac8774b69
P.S. As an aside, I'm still trying to get full functionality from the ALPS touchpad. Using some psmouse DKMS installers, I have been able to get multi-touch capabilities like two-finger scroll and two/three finger tap working. However, the 3 physical buttons don't do anything (even in xev/evtest). Passing proto=imps to the psmouse module causes them to work , but breaks multi-touch functionality. If anyone would like to offer advice for that, I'd be grateful as well.
I am currently working on a project involving a Lego Mindstorms kit. The brick is the NXT and I was curious about the bluetooth ping rates.
I ran a test of 100 pings on it and got some interesting results. The latencies seemed to fall into bands. I increased to 10,000 pings and it highlighted this trend even more clearly. Does anyone know what could cause this to happen?
In case it is relevant, the distance between the sender and receiver was about 3 metres.
Few reasons :
Buffering and internal timers to flush buffers can cause it.
Also depends on the ping intervals (i.e. time between subsequent pings), as the link might go to power save mode during inactivity and it will take a fine time to come back up.
Size of the ping packets
What bluetooth profile is used here ?