Data format 6
Lifecycle: Beta
This data format uses Bluetooth 4 advertisement extension to be compatible with Bluetooth 4 devices. Any Bluetooth 5.0 and upwards capable device should discard this data format and listen to data format E1 packets instead.
The data is decoded from "Manufacturer Specific Data" -field, for more details please check Bluetooth Advertisements section. Manufacturer ID is 0x0499 , which is transmitted as 0x9904 in raw data. The actual data payload is:
0
6
Data format (8bit)
1-2
-32767 ... 32767
Temperature in 0.005 degrees
3-4
0 ... 40 000
Humidity (16bit unsigned) in 0.0025% (0-163.83% range, though realistically 0-100%)
5-6
0 ... 65534
Pressure (16bit unsigned) in 1 Pa units, with offset of -50 000 Pa
7-8
0 ... 10000
PM 2.5, ug/m^3. Resolution 0.1/bit, range 0 ... 1000. 16bit unsigned
9-10
0 ... 40000
CO2 concentration, ppm. Resolution 1/bit, range 0 ... 40000. 16bit unsigned
11 +FLAGS b6
0 ... 500
VOC index, unitless. Resolution 1 / bit, range 0 ... 500. 9 bit unsigned, least significant bit in Flags byte
12, +FLAGS b7
0 ... 500
NOX index, unitless. Resolution 1 / bit, range 0 ... 500. 9 bit unsigned, least significant bit in Flags byte
13
0 ... 254
Luminosity, Lux. Logarithmic, range 0 ... 65535. See below for details
14
255
Reserved
15
0...255
Measurement sequence. A device sending also in E1 data format will have identical least significant byte for the same sample
16
0bVVXX XXXV
Flags. See below for details
17-19
Any valid mac
Lowest 3 bytes of device MAC address
Not available is signified by largest presentable number for unsigned values, smallest presentable number for signed values and all bits set for mac. All fields are MSB first 2-complement, i.e. 0xFC18 is read as -1000 and 0x03E8 is read as 1000. If original data overflows the data format, data is clipped to closest value that can be represented. For example temperature 170.00 C becomes 163.835 C
Data field descriptions
Temperature
Values supported: -163.835 °C to +163.835 °C in 0.005 °C increments.
Example
0x0000
0 °C
0x01C3
+2.255 °C
0xFE3D
-2.255 °C
0x8000
Invalid / not available
Humidity
Values supported: 0.0 % to 100 % in 0.0025 % increments. Higher values than 100 % are possible, but they generally indicate a faulty or miscalibrated sensor.
Example
0
0%
10010
25.025%
40000
100.0%
65535
Invalid / not available
Atmospheric Pressure
Values supported: 50000 Pa to 115534 Pa in 1 Pa increments.
Example
00000
50000 Pa
51325
101325 Pa (average sea-level pressure)
65534
115534 Pa
65535
Invalid / not available
PM 2.5
Values supported: 0 to 6553.4 (ug/m^3), however the sensor on Ruuvi supports only 1000 ug/m^3. Value is uint16_t, MSB first. Resolution is 0.1 per bit
Example
0x0000
0 ug/m^3
0x03E8
100.0 ug/m^3
0xFFFF
Invalid / not available
CO2
Values supported: 0 to 65534 (ppm), however the sensor on Ruuvi supports only 40000 ppm and in natural environment CO2 is always at least around 400 ppm. Resolution is 1 per bit. Values are uint16_t, MSB first.
0x0000
0 ppm
0x03E8
1000 ppm
0xFFFF
Invalid / not available
VOC, NOX
Volatile Organic Compounds and Nitrogen Oxides are unitless indexes which learn the installation environment and track changes over time. For VOC the index average is 100, i.e. values under 100 mean the air quality is improving and values over 100 mean the air quality is getting worse.
Nox index has base value of 1, values higher than 1 meaning there's more nitrogen oxides in the air than usual.
Both values use 9 bits, least significant bit is in Flags byte.
0x000
0
0x0E8
232
0x1FF
Invalid / not available
Luminosity
Luminosity represents the light level in the environment of the sensor. The light level is compensated with human eye sensitivity curve. Value is 8-bit unsigned logarithmic number. Values should be rounded at most to 0.01 precision.
Please note that the highest valid code is 254, and 255 is reserved for the "not available".
Decoding and encoding:
MAX_VALUE := 65535
MAX_CODE := 254
DELTA := ln(MAX_VALUE + 1) / MAX_CODE
CODE := round(ln(value + 1) / DELTA)
VALUE := exp(CODE * delta) -1Example
0x00
0 lux
0x01
0.04 lux
0x10
1.01 lux
0x80
244.06 lux
0xFE
65535.00 lux
0xFF
Invalid / not available
Measurement sequence number
Measurement sequence number gets incremented by one for every measurement. It can be used to gauge signal quality and packet loss as well as to deduplicated data entries. You should note that the measurement sequence refers to data rather than transmission, so you might receive many transmissions with the same measurement sequence number.
Please note that the highest valid value is 255, there is no "invalid / not available" value as this counter tracks the E1 format counter.
Example
0x00
0 counts
0x10
10 counts
0xFF
255 counts
Flags
Flags byte contains additional information and is interpreted bit-by-bit. "X" Means "don't care, 1 or 0". "V" Means the value of bit. Bits 1...5 are reserved. Bit 0 is least significant, bit 7 is most significant.
0bXXXX XXXV
1 -> Calibration in progress, sensor data not fully accurate yet. 0 -> Calibration complete
0bXVXX XXXX
VOC bit 9, 1-> set, 0 -> not set
0bVXXX XXXX
NOX bit 9, 1-> set, 0 -> not set
MAC address
MAC address is static, statistically unique random identifier of the device. The address is 48 bits, but this data format carries only 24 least significant bits.
Please note that the Bluetooth advertisement itself carries the full MAC address of the sensor, and most host devices can and should parse the MAC address directly from the Bluetooth metadata. However, iOS devices do not reveal the full MAC address to the application, but instead convert the MAC address to an UUID which is not guaranteed to stay static. Hence iOS devices should use these 24 bits as a static identifier of the device.
Test vectors
These test vectors are based on ruuvi.endpoints.c project. The tests are bidirectional, decode-encode results in original raw data. Encode-decode must result in same values with given precision, but floating point rounding differences may occur.
Case: valid data
Raw binary data: 0x06170C5668C79E007000C90501D9XXCD004C884F XX : Reserved
Data format
06
Temperature
29.500 C
Pressure
101102 Pa
Humidity
55.300 RH-%
PM 2.5
11.2 ug/m^3
CO2
201 ppm
VOC
10
NOX
2
Luminosity
13 026.67 Lux
Measurement Sequence
205
Flags
Calibration in progress: False
VOC b9: False
NOX b9: False
MAC
4C 88 4F
Case: maximum values
Raw binary data: 0x067FFF9C40FFFE27109C40FAFAFEXXFF074C8F4F XX : Reserved
Data format
06
Temperature
163.835 C
Pressure
115534 Pa
Humidity
100.000 RH-%
PM 2.5
1000.0 ug/m^3
CO2
40000 ppm
VOC
500
NOX
500
Luminosity
65355.00 Lux
Measurement Sequence
255
Flags
Calibration in progress: True
VOC b9: False
NOX b9: False
MAC
4C 88 4F
Case: minimum values
Raw binary data: 0x0680010000000000000000000000XX00004C884F XX : Reserved
Data format
06
Temperature
-163.835 C
Pressure
50000 Pa
Humidity
000.000 RH-%
PM 2.5
0000.0 ug/m^3
CO2
00000 ppm
VOC
000
NOX
000
Luminosity
00000.00 Lux
Measurement Sequence
000
Flags
Calibration in progress: false
VOC b9: false
NOX b9: false
MAC
4C 88 4F
Case: Invalid values
Raw binary data: 0x068000FFFFFFFFFFFFFFFFFFFFFFFFXXFFFFFFFFFF XX : Reserved
Data format
06
Temperature
NaN C
Pressure
NaN Pa
Humidity
NaN RH-%
PM 2.5
NaN ug/m^3
CO2
NaN ppm
VOC
NaN
NOX
NaN
Luminosity
NaN Lux
Measurement Sequence
255
Flags
Calibration in progress: true
VOC b9: true
NOX b9: true
MAC
FF FF FF
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