GT-WT-01 thermo/humidity sensor protocol

---

Hi,

I have a globaltronics gt-ws-06s weather station with a GT-WT-01 combined temperature/humidity sensor. I have it already many years and I pruchased it from Aldi, Lidl or Blokker (Dutch firm).
GT stands for GlobalTronics.
As there is a wheather6 sensor for the “Sempre (Aldi) GT-WT-02” sensor, I compared the readouts from my GT-WT-01 sensor with that sensor.
“Raw data” is like:

18:55:04.580 [pimatic-homeduino] debug: data: "RF receive 516 2048 4076 8976 0 0 0 0 0102020201010102020101010101010101020202020102020201020102010202020102020103"
18:55:04.632 [pimatic-homeduino] debug: received: [ 516, 2048, 4076, 8976 ] 0102020201010102020101010101010101020202020102020201020102010202020102020103
18:55:54.266 [pimatic-homeduino] debug: data: "RF receive 516 2040 4080 8972 0 0 0 0 0102020201010102020101010101010101020202020102010201020102010202020102010203"
18:55:54.283 [pimatic-homeduino] debug: received: [ 516, 2040, 4080, 8972 ] 0102020201010102020101010101010101020202020102010201020102010202020102010203
18:55:54.725 [pimatic-homeduino] debug: data: "RF receive 516 2044 4076 8976 0 0 0 0 0102020201010102020101010101010101020202020102010201020102010202020102010203"
18:55:54.740 [pimatic-homeduino] debug: received: [ 516, 2044, 4076, 8976 ] 0102020201010102020101010101010101020202020102010201020102010202020102010203
18:56:44.273 [pimatic-homeduino] debug: data: "RF receive 516 2044 4080 8964 0 0 0 0 0102020201010102020101010101010101020202020102020201020102010202020102020103"
18:56:44.296 [pimatic-homeduino] debug: received: [ 516, 2044, 4080, 8964 ] 0102020201010102020101010101010101020202020102020201020102010202020102020103
18:56:44.738 [pimatic-homeduino] debug: data: "RF receive 516 2040 4084 8984 0 0 0 0 0102020201010102020101010101010101020202020102020201020102010202020102020103"
18:56:44.753 [pimatic-homeduino] debug: received: [ 516, 2040, 4084, 8984 ] 0102020201010102020101010101010101020202020102020201020102010202020102020103
18:57:34.267 [pimatic-homeduino] debug: data: "RF receive 516 2044 4080 8980 0 0 0 0 0102020201010102020101010101010101020202020102010201020102010202020102010203"
18:57:34.283 [pimatic-homeduino] debug: received: [ 516, 2044, 4080, 8980 ] 0102020201010102020101010101010101020202020102010201020102010202020102010203
18:57:34.726 [pimatic-homeduino] debug: data: "RF receive 516 2044 4080 8968 0 0 0 0 0102020201010102020101010101010101020202020102010201020102010202020102010203"
18:57:34.741 [pimatic-homeduino] debug: received: [ 516, 2044, 4080, 8968 ] 0102020201010102020101010101010101020202020102010201020102010202020102010203

When decoding this data I could easily detect the themperature but I can’t find the humidity. I assume I’m overlooking something but I have not idea what and therefore ask for your assistance.

0111 0001 1000 0000 1011 1101 1010 1001 1101 003
0111 0001 1000 0000 1011 1101 1010 1001 1101 003
0000 1011 1101 -> 18.9
84%(should be 0101 0100)


0111 0001 1000 0000 1000 1110 1001 1111 1110 103
0111 0001 1000 0000 1000 1110 1001 1111 1110 103
1000 1110 -> 14.2
HH (humidity)

0111 0001 1000 0000 1000 0101 1010 0111 0110 103
0000 1000 0101 -> 13.3
83%(should be 0101 0011)

0111 0001 1000 0001 0001 0110 0110 0011 0000 003
0001 0001 0110 -> 27.8
49% (should be 0011 0001)

0111 0001 1000 0001 0100 0101 0100 1011 0100 003
0001 0100 0101 -> 32.5C
37% (should be 0010 0101)

0111 0001 1000 0000 1011 0110 0111 10011 000 003
0000 1011 0110 ->18.2
60% (should be 0011 1100)

0111 0001 1000 0000 1001 0001 1001 0011 0010 103
0000 1001 0001 -> 14.5
73% (should be 0100 1001)

I have only one sensor on channel 1 and I deducted from the string:

0111 0001 1000 0000 1001 0001 1001 0011 0010 103
IIII IIII xxCC TTTT TTTT TTTT
I: 8 bit ID
C: 2bit Channel -> 1 in this case
T: 12 bit Temperature : 0000 1001 0001 -> 14.5 (correct)
And now humidity?     73% (should be 0100 1001)

Anyone a clue?

I have been looking further and foundt these two links:
http://forum.pilight.org/Thread-Connect-digital-weather-sensor?page=5
and
https://github.com/merbanan/rtl_433/blob/3f066b0c7096c46a9b93b5e26fe4feec8c287aa9/src/rtl_433.c
From these two links I think I can derive battery low:

0111 0001 1000
IIII IIII BxCC

B: 0 full battery; 1 low battery -> This is correct with the readout on the weather station
CC: 00 -> Ch. 1; 01 -> Ch. 2; 10 -> Ch. 3

When changing the batteries for new ones, the Battery bit is indeed set to 0.

But I’m still puzzled about the humidty.

It should be as follows:

0111 0001 1000 0000 1001 0001 1001 0011 0010 103
IIII IIII BxCC TTTT TTTT TTTT HHHH HHHx
I: 8 bit ID
B: 0 full battery; 1 low battery
C: 2bit Channel: 00 -> Ch. 1; 01 -> Ch. 2; 10 -> Ch. 3 (channel 1 in this case)
T: 12 bit Temperature : 0000 1001 0001 -> 145 -> 14.5 (correct)
H: 7bit     73% (1001 001 = 73)

In other words: It is almost identical to the GT-WT-02 but it doesn’t work with the default weather6.

Edit: The id changes upon change of batteries.

I created a pull request for a weather12 sensor.
Pull request: https://github.com/pimatic/rfcontroljs/pull/73

Edit: I made quite some changes/fixes but the the pull request is now 100% OK.

nice, this works for the temperature readings of my rain gauge too.

17:22:20.199 [pimatic-homeduino] debug: received: [ 444, 2120, 3824, 8104 ] 0101010102020202020101010101010101020102010201010101010101010101010202010103
17:22:20.230 [pimatic-homeduino] debug: weather12:  { id: 15,
17:22:20.230 [pimatic-homeduino] debug:>  channel: 1,
17:22:20.230 [pimatic-homeduino] debug:>  temperature: 8.4,
17:22:20.230 [pimatic-homeduino] debug:>  humidity: 0,
17:22:20.230 [pimatic-homeduino] debug:>  lowBattery: true }

@Harry-van-der-Wolf Thanks you very much for your contribution. I have added the Sempre & Globaltronics stuff to the list of supported devices.

@so-what I haven’t forgotten about our conversation of rain gauge. It’s on my list and I am planning to look into this agin very soon.

@mwittig dont worry. no lifes depending on it I just took a look at my debug log and saw the wheater 12 protocol in my log, a quick search brought me here.

I have the same GT-WT-01 Sensor but it never shows correct values.
Here’s an example:

12:33:17.194 [pimatic-homeduino] data: "RF receive 552 4124 2080 9100 0 0 0 0 0102020101020202020202010101020202020202010102010102020202010201020201010103"
12:33:17.204 [pimatic-homeduino] received: [ 552, 2080, 4124, 9100 ] 0201010202010101010101020202010101010101020201020201010101020102010102020203
12:33:17.217 [pimatic-homeduino] weather12:  { id: 152,
12:33:17.217 [pimatic-homeduino]>  channel: 2,
12:33:17.217 [pimatic-homeduino]>  temperature: -101.1,
12:33:17.217 [pimatic-homeduino]>  humidity: 66,
12:33:17.217 [pimatic-homeduino]>  lowBattery: false }

You can imagine that it’s not that cold at my home .

It seems that switching the channel on the sensor, changes the values, too.

BTW: The real temperature is 22.4 degrees Celsius. And humidity is 82%.

@michbeck100 said:

You can imagine that it’s not that cold

Which receiver do you use?

@mwittig The original receiver is a GT-WS-04w (sold by Aldi Nord). On the pimatic side i’m using a RXB6 connected to an arduino nano.

I have a GT-WS-06 as receiver and also an RXB6 on an arduino nano.
However, I don’t think the receiver is of any relevance. The sequence sent by the GT-WT-01 sensor is.
The GT-WS-02 (weather 6) is an almost identical sensor with a slightly different pulse protocol.
Did you try that one?
If that works: fine, but strange.
If that doesn’t work then please share some debug lines with us. The first 2 lines (per sent signal) are important, so the “data” etcetera" and the “received” etcetera.

@Harry-van-der-Wolf weather6 doesn’t work at all. The strange thing is, that with weather12 there are still debug messages from homeduino, although i configured a device:

{
  "id": "aussenthermometer",
  "name": "Außenthermometer",
  "class": "HomeduinoRFTemperature",
  "protocols": [
    {
      "name": "weather12",
      "options": {
        "id": 152,
        "channel": 2
      }
    }
  ]
}

I thought that these debug messages disappear once a device is configured correctly.

The debug lines are my first post on this thread.

Yes, I have seen those lines in your first post but that’s only from one measurement, most of the times you need multiple measurements to deduce where the differences are.

@michbeck100 As @Harry-van-der-Wolf suggested can you please provide more logoutput? Thanks

Here is some more output. Hope that’s enough?
The actual temperature is -3.7 degrees celsius. The humidity is too low to measure. If needed i can update the debug output with values from inside the house.

23:58:01.937 [pimatic-homeduino] debug: weather12: { id: 147,
23:58:01.937 [pimatic-homeduino] debug:> channel: 4,
23:58:01.937 [pimatic-homeduino] debug:> temperature: -179.5,
23:58:01.937 [pimatic-homeduino] debug:> humidity: 88,
23:58:01.937 [pimatic-homeduino] debug:> lowBattery: false }
23:58:51.914 [pimatic-homeduino] debug: data: "RF receive 548 4128 2084 9080 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
23:58:51.926 [pimatic-homeduino] debug: received: [ 548, 2084, 4128, 9080 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
23:58:51.938 [pimatic-homeduino] debug: weather12: { id: 147,
23:58:51.938 [pimatic-homeduino] debug:> channel: 4,
23:58:51.938 [pimatic-homeduino] debug:> temperature: -179.5,
23:58:51.938 [pimatic-homeduino] debug:> humidity: 88,
23:58:51.938 [pimatic-homeduino] debug:> lowBattery: false }
23:59:41.915 [pimatic-homeduino] debug: data: "RF receive 544 4132 2084 9084 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
23:59:41.926 [pimatic-homeduino] debug: received: [ 544, 2084, 4132, 9084 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
23:59:41.939 [pimatic-homeduino] debug: weather12: { id: 147,
23:59:41.939 [pimatic-homeduino] debug:> channel: 4,
23:59:41.939 [pimatic-homeduino] debug:> temperature: -179.5,
23:59:41.939 [pimatic-homeduino] debug:> humidity: 88,
23:59:41.939 [pimatic-homeduino] debug:> lowBattery: false }
00:00:31.916 [pimatic-homeduino] debug: data: "RF receive 544 4128 2084 9104 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:00:31.929 [pimatic-homeduino] debug: received: [ 544, 2084, 4128, 9104 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:00:31.942 [pimatic-homeduino] debug: weather12: { id: 147,
00:00:31.942 [pimatic-homeduino] debug:> channel: 4,
00:00:31.942 [pimatic-homeduino] debug:> temperature: -179.5,
00:00:31.942 [pimatic-homeduino] debug:> humidity: 88,
00:00:31.942 [pimatic-homeduino] debug:> lowBattery: false }
00:01:21.916 [pimatic-homeduino] debug: data: "RF receive 544 4128 2088 9092 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:01:21.927 [pimatic-homeduino] debug: received: [ 544, 2088, 4128, 9092 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:01:21.940 [pimatic-homeduino] debug: weather12: { id: 147,
00:01:21.940 [pimatic-homeduino] debug:> channel: 4,
00:01:21.940 [pimatic-homeduino] debug:> temperature: -179.5,
00:01:21.940 [pimatic-homeduino] debug:> humidity: 88,
00:01:21.940 [pimatic-homeduino] debug:> lowBattery: false }
00:02:11.917 [pimatic-homeduino] debug: data: "RF receive 548 4128 2080 9100 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:02:11.928 [pimatic-homeduino] debug: received: [ 548, 2080, 4128, 9100 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:02:11.940 [pimatic-homeduino] debug: weather12: { id: 147,
00:02:11.940 [pimatic-homeduino] debug:> channel: 4,
00:02:11.940 [pimatic-homeduino] debug:> temperature: -179.5,
00:02:11.940 [pimatic-homeduino] debug:> humidity: 88,
00:02:11.940 [pimatic-homeduino] debug:> lowBattery: false }
00:03:01.919 [pimatic-homeduino] debug: data: "RF receive 544 4132 2088 9088 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:03:01.930 [pimatic-homeduino] debug: received: [ 544, 2088, 4132, 9088 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:03:01.942 [pimatic-homeduino] debug: weather12: { id: 147,
00:03:01.942 [pimatic-homeduino] debug:> channel: 4,
00:03:01.942 [pimatic-homeduino] debug:> temperature: -179.5,
00:03:01.942 [pimatic-homeduino] debug:> humidity: 88,
00:03:01.942 [pimatic-homeduino] debug:> lowBattery: false }
00:03:51.919 [pimatic-homeduino] debug: data: "RF receive 548 4124 2084 9104 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:03:51.930 [pimatic-homeduino] debug: received: [ 548, 2084, 4124, 9104 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:03:51.942 [pimatic-homeduino] debug: weather12: { id: 147,
00:03:51.942 [pimatic-homeduino] debug:> channel: 4,
00:03:51.942 [pimatic-homeduino] debug:> temperature: -179.5,
00:03:51.942 [pimatic-homeduino] debug:> humidity: 88,
00:03:51.942 [pimatic-homeduino] debug:> lowBattery: false }
00:04:41.919 [pimatic-homeduino] debug: data: "RF receive 544 4128 2088 9096 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:04:41.930 [pimatic-homeduino] debug: received: [ 544, 2088, 4128, 9096 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:04:41.943 [pimatic-homeduino] debug: weather12: { id: 147,
00:04:41.943 [pimatic-homeduino] debug:> channel: 4,
00:04:41.943 [pimatic-homeduino] debug:> temperature: -179.5,
00:04:41.943 [pimatic-homeduino] debug:> humidity: 88,
00:04:41.943 [pimatic-homeduino] debug:> lowBattery: false }
00:05:31.921 [pimatic-homeduino] debug: data: "RF receive 544 4132 2088 9092 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:05:31.933 [pimatic-homeduino] debug: received: [ 544, 2088, 4132, 9092 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:05:31.948 [pimatic-homeduino] debug: weather12: { id: 147,
00:05:31.948 [pimatic-homeduino] debug:> channel: 4,
00:05:31.948 [pimatic-homeduino] debug:> temperature: -179.5,
00:05:31.948 [pimatic-homeduino] debug:> humidity: 88,
00:05:31.948 [pimatic-homeduino] debug:> lowBattery: false }
00:06:21.922 [pimatic-homeduino] debug: data: "RF receive 544 4132 2088 9096 0 0 0 0 0102020102020101020201010102020201010101010102010102010102020202010201020103"
00:06:21.935 [pimatic-homeduino] debug: received: [ 544, 2088, 4132, 9096 ] 0201010201010202010102020201010102020202020201020201020201010101020102010203
00:06:21.947 [pimatic-homeduino] debug: weather12: { id: 147,
00:06:21.947 [pimatic-homeduino] debug:> channel: 4,
00:06:21.947 [pimatic-homeduino] debug:> temperature: -179.5,
00:06:21.947 [pimatic-homeduino] debug:> humidity: 88,
00:06:21.947 [pimatic-homeduino] debug:> lowBattery: false }

Now I have the same problem! I find the GT-WT-01 sensor cheap on Ebay and thought that they are supported, but i also have strange values

I found out, that there is also a problem with the channel. It has only 3 channels. But when you switch the temperature changes and the channel code is not changing. (Just saw that michbeck100 already mention that, sorry!)

Actual temperature is 22.6° C and 66% humidity. This is the log from channel 1 to 3

debug [pimatic-homeduino]: weather12:  { id: 153,
  channel: 1,
  temperature: 103.8,
  humidity: 18,
  lowBattery: false }
debug [pimatic-homeduino]: received: [ 592, 2036, 4080, 9056 ] 0201010202010102010101010102010101010101020202010101020101020101010102010203
debug [pimatic-homeduino]: data: "RF receive 592 4080 2036 9056 0 0 0 0 0102020101020201020202020201020202020202010101020202010202010202020201020103"
debug [pimatic-homeduino]: weather12:  { id: 153,
  channel: 1,
  temperature: 129.4,
  humidity: 18,
  lowBattery: false }
debug [pimatic-homeduino]: received: [ 592, 2036, 4080, 9060 ] 0201010202010102010101010102010201010101020202010101020101020101010102010203
debug [pimatic-homeduino]: data: "RF receive 592 4080 2036 9060 0 0 0 0 0102020101020201020202020201020102020202010101020202010202010202020201020103"
debug [pimatic-homeduino]: weather12:  { id: 153,
  channel: 1,
  temperature: 155,
  humidity: 18,
  lowBattery: false }
debug [pimatic-homeduino]: received: [ 592, 2040, 4080, 9056 ] 0201010202010102010101010102020101010101020202010101020101020101010102010203
debug [pimatic-homeduino]: data: "RF receive 592 4080 2040 9056 0 0 0 0 0102020101020201020202020201010202020202010101020202010202010202020201020103"

Thanks in advance for your help! If I could help in anyway, please let me know

Guys, may be @Icesory can have look at this. It seems like the raw data is completely wrong. I fiddled a helper tool to peek potential numeric values in the bit stream, but I cannot find any fixtures. If you want to give it a try, here is the fiddle: https://jsfiddle.net/WittigMarcus/7aqsf09j/

Note, the temperature typically is a number divided by 10. For example, the value 1038 actually is 103,8 if interpreted as temperature.

@mwittig If I understand your script in the right way:
This is the right:
michbeck100: -3.7°C: offset: 16 bits: 12 bin 111111011011 signed: -37

my value:
22.6°C: offset: 16 bits: 12 bin 000011100010 signed: 226
66% humidity: offset: 28 bits: 8 bin 01000010 unsigned: 66
offset: 28 bits: 8 bin 01000010 signed: 66

So for my sensor it works now, but at the moment i don’t know how to pull it to coffee or github:

if (helper.binaryToNumber(binary, 12, 12) === 1) {
    lowBattery = true;
  } else {
    lowBattery = false;
  }
  return result = {
    id: helper.binaryToNumber(binary, 0, 11),
    channel: helper.binaryToNumber(binary, 14, 15) + 1,
    temperature: helper.binaryToSignedNumberMSBLSB(binary, 16, 27) / 10,
    humidity: helper.binaryToNumber(binary, 28, 35),
    lowBattery: lowBattery
  };

I hope that will help to fix the problem Thanks for your help!

@techbarney Where did you change these values? in weather12.coffee of rfcontroljs?
I’m asking because there are some more offsets that seems to be changed, not just the one for temperature and humidity.

@techbarney Oh, great. I didn’t spot it when trialing it

I think we should craft a new protocol for it. @michbeck100 this is done as part of rfcontroljs. I’ll draft a protocol for testing tommorrow.