I’ve now learned some details on BLE, and have written a program that listens for BLE advertisements from either type of thermometer and logs the temperature and humidity in a text file. The code for my project is available on GitHub. https://github.com/wcbonner/GoveeBTTempLogger
The same program can also be called to get the last value from the log and produce output compatible with MRTG. MRTG is not the best method for graphing these temperatures, because all graphs start with zero on the Y axis, and neither the temperature or humidity is likely to be near zero.
My program seems to receive advertisements from each thermometer about every ten seconds. I’ve had a friend running the code in his location with a different set of thermometers and it doesn’t get advertisements nearly as frequently. I don’t know if that’s just because environment is different, or if there’s something else going on.
Last week I came across a deal on a small thermometer with display and Bluetooth access for under $10 so I had to give it a try. The fact that the data is available via bluetooth instead of via a web service was a major selling point for me. I am hoping to be able to to log the data via a Raspberry Pi4.
I installed the Govee Home app on my iPhone and it was able to find the device, communicate with it, and pull both current and accumulated data.
When I attempted to find it from my Pi4 it was much more difficult. I live in an apartment with units all around. I’m not just dealing with my own devices that may be visible, but my neighbors as well.
I managed to find the device using linux command line tools, but was not able to successfully connect. A friend suggested BLE Scanner 4.0 for my iPhone for discovering the details, and it was at least able to confirm what I should be looking for using the linux command line tools. I still had timeout issues with the iPhone app, but at least was able to confirm that I could connect to the device and retrieve GUID information.
This is my first time attempting to gather data from a Bluetooth device. I’m still in the research and test phase. I’m listing a bunch of the URLS I’ve found that have been helpful.
From the command line on my Pi4 I already had the tools installed to try several Bluetooth commands. I believe they were installed as part of the bluez package. The first two commands below get details on the Raspberry Pi Bluetooth hardware, then the hcitool lescan command produced a lot of devices, and I found the line referencing the GVH5075 so I could use the address in further commands.
Another command that I attempted before I used the hcitool command was the bluetoothctl command. It scrolls a lot of data, but now that I have an idea what I’m looking at, I may be able to see announcement data from the thermometer periodically in the stream by filtering just to see the data coming from the MAC address.
Last week Microsoft released a new command line tool in the Microsoft Store. It requires running Windows Version 2004.
Last year when I was importing pictures from a camera memory card, the import program crashed. It only managed to import a few of the pictures, but it deleted all of the pictures from the memory card.
Because of my long history understanding how file systems work, I knew that the pictures were likely still on the card, just not in the directory system I couldn’t find a tool at the time to recover the files. I’d put a label on the card and set it aside. As soon as I heard about this program I installed it and tried it out on the memory card.
The funny thing is that it recovered several thousand images, going back several years. I ran it in signature mode, looking for jpeg files. In doing that, It’s just looking at all the data blocks on the drive, looking for jpeg files.
This time I used Adobe Lightroom CC to import the images and group them by the embedded EXIF data. Looking at the details, the photos that got deleted by mistake were likely from 10/28/2018. All of the photos attributed to 06/29/2020 are missing exifdata, and are just recorded as the date they were recovered.
This is a good reminder that you probably don’t want to throw away old digital media, even when you think you’ve gotten rid of all incriminating data.
Sometimes I go to a place I’ve been before and my computer remembers the WiFi password while my brain does not. The following Windows PowerShell commands will display most of the remembered passwords.
netsh wlan show profiles
netsh wlan show profiles name=’ProfileToDisplay’ key=clear
The first command displays all of the networks your computer has remembered. It can be rather long if you’ve had your computer for several years and done a reasonable amount of traveling and using WiFi in strange locations.
The second command takes the profile name that you retrieved with the first command and displays details of the selected profile. The password is displayed as the Key Content section of the Security settings.
I have IPv6 set up and running on my home network, but there was some testing I wanted to run remotely. My local Starbucks WiFi isn’t running IPv6 according to my quick test with https://test-ipv6.com/
The same test from my iPhone on TMobile shows it’s running IPv6 by default.
I had read somewhere that Apple supported IPv6 on the personal hotspot through a loophole in the netmask routing algorithms used by most providers..
When I tested the local network connection on my computer while connected to the Apple Personal Hotspot, it appeared to be running IPv6.
Unfortunately when I connected to my phone from my computer via the personal hotspot, I wasn’t able to get positive IPv6 results. Obviously the hotspot was working since I was able to get to the test site via IPv4 without issues.
My nearly four year old Microsoft Surface Pro 4 recently developed a screen flicker issue. I’m sure it was some driver update that was installed, but I’m not exactly sure when. The observed activity is that a horizontal section at the bottom of the screen about the same size of the mouse cursor flickers with data that is duplicated from the top of the screen. The rest of the screen appears to be bouncing up and down by one scan line, making the text nearly unreadable.
I searched online, and found references to flicker problems with some cases being purely hardware related and requiring replacement by Microsoft. I also found references to the problem only occurring after the screen data had not changed for a few seconds. This static screen problem matched my problem exactly.
I found a workaround by enabling the seconds display in the clock in the task bar. This is done by creating a registry entry. If the following is in a “.reg” file it will set the value to show the seconds on the clock.
Windows Registry Editor Version 5.00
I read that the seconds are not enabled by default because it saves a bit of processing power, which can be important on battery powered devices. For me the difference is minimal and worth not spending more time researching a probable driver issue that may be taken care of automatically in some future windows update.
I hope that this helps someone else. The screen flicker/jitter was annoying and I wasn’t able to find the root cause.
I recently came across WinFi Lite, and while it claims to be in beta and for professionals only, it’s currently my favorite WiFi analysis program. The fact that it was in the Microsoft store gives me the idea that it will uninstall cleanly if I decide to get rid of it later.
The default view shows details about both 2.4 and 5 GHz networks nearby. The first picture was what it looked like when I ran it in my local Starbucks on my Microsoft Surface 4 Pro. The next picture was what it looked like when I ran it in my apartment. In my apartment I was connected to my network via wired ethernet, so the Surface WiFi adapter wasn’t being used for my active connection. At Starbucks, I was connected to the WiFi.
While I was at Starbucks, the number of networks it could see was 188. That number is visible in the top right of the image. Just to the left of that number are a set of buttons that allow you to look at 2.4GHz, 5GHz, or All available networks.
My apartment showed only 161 networks by comparison, but that number was bouncing around as it rescanned in both locations. I was surprised that the Starbucks had so many visible networks. There are a lot of details available in this tool, and it’s current price makes it an interesting tool to work with. I used to like inSSIDer, but the developers choice to dumb down the free version led me to drift away from it.