I use sudo hcitool rssi AA:BB:CC:DD:EE:FF to test 2 phones, but the results are 0. I also try to use python program (https://github.com/ewenchou/bluetooth-proximity), the result is also 0. I don't know where went wrong. Besides, I use bluetoothctl-scan on and can get their mac address and rssi although the value is not accuracy.
Please, give me some advice.
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But after I use sudo btmon | grep RSSI and sudo hcitool lescan, it shows mac address and RSSI of all the device. So what should I do to make it display only the RSSI of the device I want continuously?
I don't know if btmon can do it, if can't, which way should I use? I just want to continuously obtain the Bluetooth rssi value of a device. Please, give me some advice.
When I run:
iwconfig wlan0 | grep -i quality
on my Raspberry Pi, with a wifi card installed, it reports back to me with:
Link Quality=99/100 Signal level=48/100 Noise level=0/100
How can I get iwconfig or some other network tool to report the signal level back to me in dBm instead of an arbitrary fraction?
It's a matter of the Network Interface Card or of the relatives Drivers.
To workaround you can use this simple formula I to do the conversion.
dbm=(fraction_of_total/2)-100
Of course is an approximation and results may vary from chipset to chipset but is how I solved.
You can alternatively find the correct Drivers if you know the wifi card is capable RSSI sampling. But that's usually not easy.
I am working with HM10 BLE chip with Arduino. I am able to establish serial communication between the two. In the manufacturer manual from jnhuamao.cn, it says that for AT+DISC? , "...Before V535 max results is 6, Since V535 not limit"
AT+DISC? is the AT command for scanning nearby BLE devices. The firmware for my chips are V539 and V540.
However, I am only able only received maximum 6 devices as scan result in the serial monitor. And they are different everytime. (I have 8 chips powered up nearby). Has anyone ran into the same problem? What could be the problem? What might be the solutions?
THANKS A LOT
the number of discoverable devices for hm-10 is 6 devices in one go.
its in their datasheet.
Even im facing a similar issue.
Im looking for something that will give me upto 20 devices in the scann results.
I'm trying to get data from a mercury analyzer (Seefelder-Messtechnik Hg Analyzer 3000) that gives output to a 9-pin R232 serial port to my OSX 10.10 laptop.
I've followed the steps described here to install the PL-2303 driver:
http://pbxbook.com/other/mac-tty.html
The device manual (http://www.seefelder-messtechnik.com/V71-3-02-21e.pdf) lists the communication protocol as "9600 Baud, 8 data bit, 1 stop bit, no log,
no parities".
I attempt to read from the device by using the 'screen' command:
screen /dev/tty.usbserial 9600
The result is a string of seemingly non-sensical characters that print to the screen in a regular interval:
�8b4����b��8b48bs��8G�8b�8���8������8����< 8�8��b��KW��\b����8b����b� �b�b����KW�K �8b��\G�� �<���8�8b�"���[��؉���bG�3�ˁ�G��\K��[W�pb�8��8ʱ�\pa���ʁ�c t��8�h¡�38b�8�q�����\�8���bS�8b8�8�q���X��8��<��£8���2�8�����ؖ�ؖ�ؖ�8bS��\�܉�ؖ����[S�8��s���fq�8�����������8fq����������S�܊��b���b�؉����\���S��K���ݎ����S��b��b��S����S�\������KS��S�؊��\S�1S�\b�S�؉�\�ذ����KS�\����S����bS�؉�����1S�؊��[����ز������؉\���ز��\����i���$\�$���\��8���$��\�\����܂�زXk�B��7��\k�\X�<��8Xkz��Yj��L�������H�\���]j�،k:��Yj�؈��
I've also tried using 'minicom' rather than screen, and get a different ("?]???ܰ??Yk??2"), but also non-sensical result. I saw that there was another SO query similar to mine that remains unsolved: weird characters displayed during serial communication OSX
Any tips? It looks to me that I'm not interpreting the output correctly, but I don't know what to try next.
The solution was to read from the machine at a higher baud rate (~57600), despite what the manual and online reference said. Reading at 57600 baud made the result plain-text and usable. Thanks for your ideas!
I've followed the steps described here to install the PL-2303 driver
I've also had occasional electrical ground problems with Prolific USB-RS232 adapters. Problem would manifest as garbled data that looked similar to a baud rate issue or what you posted.
You can check if it's a ground issue by measuring for continuity between the ground pin (pin #5) on the DE-9 (aka DB-9) side of the Prolific adapter and the ground pin of the USB side (pin #4, "far left", of the A connector). You'll probably measure infinite resistance with a multimeter. Try the same with a FTDI USB-RS232 adapter, and instead I get a dead short between the ground pins as expected.
Be sure to plug the instrument's and PC's power supplies into the same power strip.
As a last resort try grounding the instrument's chassis/case with the PC using copper wire
I develop an Android application running on Motorola RAZR XT910 with OS version 4.0.4.
This application uses the Motorola_ICS_R2_sdkaddon_100 BluetoothGattService.jar and BluetoothGatt.jar libraries and communicates with Bluetooth
Low Energy Sensor Tags (TI CC2540,TI CC2541,Blue Radios Sensor Tags).
On Discovery procedure I always read the rssi value equal to 0 . I use the following code
to read the rssi value on receiving the Intent BluetoothDevice.ACTION_FOUND:
short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,(short) 0);
Also for non Bluetooth low energy devices,the rssi value i read is ok (not equal to 0).
Can anyone help me??
thanks
I found a similar issue on the TI discussion site for using the Vender Specific query for RSSI. It seems that it works for Classic BT but returns an error code of 2 for BLE.
http://e2e.ti.com/support/low_power_rf/f/660/t/289391.aspx
It might be a fundamental limit that you can't get the value. In your case, the getShortExtra might not return the error code (2) and just return a 0 as RSSI.