Could you add support to the HEM-7140T1?

[Fadel-K]

I would love it if you could add support to HEM-7140T1.

I have attached the btsnoop file from my phone while it ran the omron connect app.

btsnoop_hci.log

[userx14]

Hi @Fadel-K ,

sorry it took me quiet some time to get to this. The communication in your log looks simmilar the one from the other omron devices I worked with. Here is my initial decoding attempt:

BT-Communication, response indented
08 0000 0000 10 0018                                            #start communication
    08 8000 0000 10 0098
08 0100 0260 2c 0047                                            #settings read
    34 8100 0260 2c 00400080008000802100008000000080000101000a000000000000000c00ffff00000000000000000000fe00 00e2
08 0100 028c 18 009f                                            #settings read
    20 8100 028c 18 c8a800000000000019030e0e0b10c3000000000000000000 0095
08 0100 02e8 38 00db                                            #likely data
    40 8100 02e8 38 584e4419ac0d1e1600001400040058494119ac0d651700001500450054494119ac0df21700001600cf0076756219ac0d4c18000017009a00 00f3
08 0100 0320 38 0012                                            #likely data
    40 8100 0320 38 5b4c4619ac0da9180000180098005f504419ac0df81c00001900f2005c474119ac0dda1d00001a00c7005e4b4719ac0d991e00001b009400 00e4
08 0100 0358 38 006a                                            #likely data
    40 8100 0358 38 5a4f4519ad0d421000001c002f005c484419ad0d821100001d006b005d503b19ad0d6d1200001e00580064513c19ad0d0f1500001f000700 0022
08 0100 0390 1c 0086                                            #likely data
    24 8100 0390 1c 58504519ae0d681c0000200065005a513e19cb0d4a1b000021006000 0016
18 01c0 02a4 10 00400080008000802100008000000080 008e           #does not change values
    18 81c0 02a4 10 00400080008000802100008000000080 000e
18 01c0 02d0 10 c8a800000000000019030e0e0b11c400 00bf           #only changes 10c300->11c400, maybe time sync update?
    18 81c0 02d0 10 c8a800000000000019030e0e0b11c400 003f       
08 0f00 0000 00 0007                                            #end communication
    088f000000000087

If you have the time please test the branch I made for testing: https://github.com/userx14/omblepy/compare/hem-7140t-testing and check if it works. It is possible that I have misidentified some bytes in the records, so if the measurement time or other values are off, please let me know.

Best regards,
Benjamin

[Fadel-K]

Thank you for your reply @userx14 ! I am unable to pair the monitor using preexisting models or the new testing file on my RPi running Ubuntu 22.04.5 LTS. I tried the troubleshooting steps as well. It gave the following error on the terminal:

File "/home/fadel/Downloads/omblepy-main/./omblepy.py", line 395, in <module>
    asyncio.run(main())
  File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/home/fadel/Downloads/omblepy-main/./omblepy.py", line 364, in main
    await bleClient.pair(protection_level = 2)
  File "/home/fadel/.local/lib/python3.10/site-packages/bleak/__init__.py", line 629, in pair
    return await self._backend.pair(*args, **kwargs)
  File "/home/fadel/.local/lib/python3.10/site-packages/bleak/backends/bluezdbus/client.py", line 473, in pair
    assert_reply(reply)
  File "/home/fadel/.local/lib/python3.10/site-packages/bleak/backends/bluezdbus/utils.py", line 22, in assert_reply
    raise BleakDBusError(reply.error_name, reply.body)
bleak.exc.BleakDBusError: [org.bluez.Error.AuthenticationCanceled] Authentication Canceled

Can you guide me on further steps? Thanks for your help!

[userx14]

The error you are seeing happens during the pairing of the bluetooth devices and comes from the bluez backend.
It can be caused by two things:

• For the initial pairing for the devices I've tested with, one has to confirm a pairing dialog on the os. However some linux distribution do not correctly display it. There is some info in the linux part of the troubleshooting section about using bluetoothctl in a second terminal to get it working. Do you get a pairing request dialog on your pi?
• With some linux versions (my suspicion is that it is connected to the bluez version) I just was not able to get the pairing process working. I think it was also ubuntu 22 and I did unfortunately not find a fix for this, other than to use a different operating system / version. Some people reported that it worked with their pi 4b using raspberry pi os.

One alternative could also be the esp32 version, where the OS specific bluetooth stack is bypassed by using a esp32 board to do the bluetooth pairing and communication. The omron device specific decoding still happens on the PC side. So you can just copy the hem7140t.py file from the development branch into the deviceSpecific folder for the esp32 branch and it should work.

If you have a win10 device I would recommend to do the first tests with it.
The pairing dialog has a very short timeout and needs to be accepted quickly, but in general it works more reliably.

[Fadel-K]

Thank you for your response. I tried the troubleshooting section about using bluetoothhctl in a 2nd terminal, I didn't get any pairing request on it.

I am reluctant to change to raspbian os. Do you know which versions of Ubuntu/bluez are known to work? I don't have a win 10 device sadly, but I will try to get acccess to one and update if I am successful.

[userx14]

I did not test so much with Ubuntu, the only thing I remember is that 20.04 was not able to pair with the device. On an older debian image, I had success with bluez 5.55.