Payload Format
Overview
The payload of up and downlink messages consists of an arbitrary number of data structs (DS) of different types and lengths.
| DS 1 | DS 2 | ... | DS n |
|---|---|---|---|
Each data struct is a combination of a header and the actual data payload:
| L | T | payload |
|---|---|---|
The header consists of two fields:
| Field | Description |
|---|---|
| L | Length of data struct, 1 byte, not including the length byte itself |
| T | Data struct type, 1 byte |
Data Encoding
Signed integers use two’s complement for encoding.
Important
Unless otherwise noted, payloads will use little endian data encoding.
Uplinks
The following table gives an overview of the uplinks of miro Insight and miro Outsight.
| Message | Description | OEM-LWEU868 | Size | ID | Byte | Byte | Byte | Byte | Byte | Byte |
|---|---|---|---|---|---|---|---|---|---|---|
| None | None | 0 | 0 | |||||||
| TempRH | Membrane | 1+3*m | 1 | T[1] | T[0] | RH | ||||
| CO2 data | 1+2*m | 2 | ||||||||
| Battery status | 5 | 3 | ||||||||
| TempRH_EC2 | 2 | 4 | ||||||||
| Common settings | y | 6 | 5 | |||||||
| CO2 settings | 7 | 6 | ||||||||
| SettingsDaynight_EC2 | 7 | |||||||||
| SettingsTemp_EC2 | 5 | 8 | ||||||||
| Battery voltage | y | 3 | 9 | |||||||
| Firmware hash | y | 5 | 10 | |||||||
| Door alarm | 9 | 11 | ||||||||
| Door alarm cleared | 7 | 12 | ||||||||
| Door status | 8 | 13 | ||||||||
| Door settings | 9 | 14 | ||||||||
| IAQ data | 1+2*m | 15 | ||||||||
| Pressure data | 1+3*m | 16 | ||||||||
| ReportInterval | 3 | 17 | Intv[1] | Intv[0] | ||||||
| Temperature external | cable DS18B20 | y | 1+4*m | 18 | Ch1_T[1] | Ch1_T[0] | Ch2_T[1] | Ch2_T[0] | ||
| TempRH_Internal | In the box | 1+3*m | 19 | T[1] | T[0] | RH | ||||
| Light data | Membrane | 1+2*m | 20 | val[1] | val[0] | |||||
| - m: number of measurements |
Important
All uplinks are sent on LoRaWAN port 15.
Report Interval
Measurement data can be accumulated by the sensor sent out as multiple values in one message. As there are no timestamp information within the message, only the time of last measurement is known. It is equal to the timestamp of the message. To be able to calculate the timestamps of older messages, the measurement interval has to be known by the decoder. This can either be a static configuration or it can be enabled on the device to report the current interval with every measurement message.
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x03) | uint8 |
| 1 | 1 | Message type (0x11) | uint8 |
| 2 | 2 | measurement interval in sec | uint16 |
Temperature and humidity data
The temperature and humidity data message type is used to upload a number of sensor measurement values. Message length is dependent on the number of accumulated measurements: \(L = 1 + 3 * N\_{meas}\)
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x03) | uint8 |
| 1 | 1 | Message type (0x01) | uint8 |
| 2-4 | 3 | Measurement 1 | see below |
| 5-7 | 3 | Measurement 2 | see below |
| ... | ... | ... | ... |
| \(3*N-1\) to \(3*N+1\) | 3 | Measurement \(N\) | see below |
The number of values per message is depending on the sensor configuration. The oldest measurement value is transmitted first. The last value is taken just before transmission. As the measurement interval configuration is known, the timestamps of all other pairs can be computed upon reception.
Single Measurement
| Byte | Size | Description | Format |
|---|---|---|---|
| 0-1 | 2 | Temperature in 0.01 °C | int16 (two’s complement) |
| 2 | 1 | Humidity in 0.5 % | uint8 |
Important
In case of sensor failure, a single measurement will have the payload 0x8000
Temperature external
The temperature and humidity data message type is used to upload a number of sensor measurement values. Message length is dependent on the number of accumulated measurements: \(L = 1 + 4 * N\_{meas}\)
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x03) | uint8 |
| 1 | 1 | Message type (0x12) | uint8 |
| 2 | 1 | Number of channels | uint8 |
| 3-6 | 4 | Measurement 1, channel 1 and channel 2 | see below |
| 7-10 | 4 | Measurement 2, channel 1 | see below |
| ... | ... | ... | ... |
| \(4*N-1\) to \(4*N+2\) | 4 | Measurement \(N\) | see below |
The number of values per message is depending on the sensor configuration. The oldest measurement value is transmitted first. The last value is taken just before transmission. As the measurement interval configuration is known, the timestamps of all other pairs can be computed upon reception.
Single temperature (external) measurement
| Byte | Size | Description | Format |
|---|---|---|---|
| 0-1 | 2 | Temperature channel 1 in 0.01 °C | int16 (two’s complement) |
| 2-3 | 2 | Temperature channel 2 in 0.01 °C | int16 (two’s complement) |
Important
In case of sensor failure, a single measurement will have the payload 0x8000
Light
The light data message type. The message length is dependent on the number of accumulated measurements: \(L = 1 + 2 * N\_{meas}\)
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length | uint8 |
| 1 | 1 | Message type (0x14) | uint8 |
| 3-6 | 4 | Measurement 1 | see below |
| 7-10 | 4 | Measurement 2 | see below |
| ... | ... | ... | ... |
| \(2*N-1\) to \(2*N+2\) | 4 | Measurement \(N\) | see below |
The number of values per message is depending on the sensor configuration. The oldest measurement value is transmitted first. The last value is taken just before transmission. As the measurement interval configuration is known, the timestamps of all other pairs can be computed upon reception.
Single light measurement
| Byte | Size | Description | Format |
|---|---|---|---|
| 0-1 | 2 | Light in LUX | uint16 |
Important
In case of saturation and/or failure, the sensor delivers 0xFFFF
Common settings
This uplink will transmit the common device settings related uplink interval and retransmissions. It happens right after the sensor has joined a network and when the settings have been changed through a downlink. It will always be transmitted as a confirmed message. Retransmissions happen immediately after the NACK has been received.
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x06) | uint8 |
| 1 | 1 | Message type (0x05) | uint8 |
| 2-3 | 2 | Measurement interval in seconds | uint16 |
| 4 | 1 | Send cycle | uint8 |
| 5 | 1 | Flags and number of retransmissions, combination of: Bit 7 = Confirmed uplinks (0 = off, 1 = on) Bit 6 = LED (0 = off, 1 = on) Bit 5 = ADR (0 = off, 1 = on) Bit 4: Cont. VOC measurement Bit 3: Report Interval Bit 2-0: RFU |
bitfield |
| 6 | 1 | Number of retransmissions: Bit 7-4: RFU Bit 3-0: Number of retransmission |
bitfield |
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x05) | uint8 |
| 1 | 1 | Message type (0x05) | uint8 |
| 2-3 | 2 | Measurement interval in seconds | uint16 |
| 4 | 1 | Send cycle | uint8 |
| 5 | 1 | Flags and number of retransmissions, combination of: Bit 7 = Confirmed uplinks (0 = off, 1 = on) Bit 6 = LED (0 = off, 1 = on) Bit 5 = ADR (0 = off, 1 = on) Bit 4: Cont. VOC measurement Bit 3-0: Number of retransmission |
bitfield |
Battery voltage
The battery voltage message reports the voltage measured by the microcontroller. It is reported in 10 mV.
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x03) | uint8 |
| 1 | 1 | Message type (0x09) | uint8 |
| 2-3 | 2 | Battery voltage in 0.01 V | uint16 |
Firmware Hash
The firmware hash message is sent once after successfully joining the network. The hash value can be used to identify the current firmware version of the device.
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x05) | uint8 |
| 1 | 1 | Message type (0x0A) | uint8 |
| 2-5 | 4 | Firmware hash | uint32 |
Downlinks
Downlink messages are used to change the configuration of the device. They use the same general payload format as uplinks.
Important
All downlinks must be sent on the LoRaWAN port 3!
Common configuration
The common configuration message type is used to set the basic configuration such as measurement interval and send cycle.
Common configuration
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x06) | uint8 |
| 1 | 1 | Message type (0x87) | uint8 |
| 2-3 | 2 | Measurement interval in seconds | uint16 |
| 4 | 1 | Send cycle | uint8 |
| 5 | 1 | Flags and number of retransmissions: Bit 7 = Confirmed uplinks (0 = off, 1 = on) Bit 6 = LED (0 = off, 1 = on) Bit 5 = ADR (0 = off, 1 = on) Bit 4: Continuous VOC Bit 3: Report Interval Bit 2-0: RFU (send as 0) |
bitfield |
| 6 | 1 | Bit 7-4: RFU (send as 0), Bit 4-0: Number of retransmissions |
Example: 0x0687B400032002
- 0x05: length
- 0x87: type
- 0xB400: measurement interval 180 seconds (little endian: 0x00B4)
- 0x03: SendCycle 4x180 = 12min (-1 encoded)
- 0x20: flags (0b00100000): Not confirmed, LED off, EDR on, VOC off repeated interval off
- 0x02: number of retransmissions: 2
For FW version 1.2.0 and older a 1 byte shorter message was used and the number or retransmissions was the last 4 bits (LSB) of the flags.
Example for FW version 1.2.0 and older: 0x0587B4000322
- 0x05: length
- 0x87: type
- 0xB400: measurement interval 180 seconds (little endian: 0x00B4)
- 0x03: SendCycle 4x180 = 12min (-1 encoded)
- 0x20: flags (0b00100000): Not confirmed, LED off, EDR on, VOC off repeated interval off, number of retransmissions 2
Reset
This downlink will reset the device with delay. Device will reset after reset delay seconds if magic number matches
| Byte | Size | Description | Format |
|---|---|---|---|
| 0 | 1 | Message length (0x06) | uint8 |
| 1 | 1 | Message type (0x84) | uint8 |
| 2-5 | 4 | Magic number 0xF98BD419 | uint32 |
| 6 | 1 | Reset delay in seconds | uint8 |
Example: 0x0684F98BD4190A
- 0x06: length
- 0x84: type
- 0xF98BD419: magic number
- 0x0A: delay 10 sec
For FW version 1.2.0 and older a 1 byte shorter message was used and the delay was not available
Example: 0x0584F98BD419
- 0x05: length
- 0x84: type
- 0xF98BD419: magic number