3.1 Data Protocol for Remote Sensor Telegram
The following table provides details about the remote sensor data protocol parameters.
The Manchester encoding is using a low-to-high transition for a ‘0’ bit
and a high-to-low transition for a ‘1’ bit.
| Protocol Item | #Of Data Bits | Value | Description |
|---|---|---|---|
| Preamble | 55 | 1 | Pre-burst for wake-up and synchronization |
| Start bit | 1 | 0 | Start bit to indicate data payload |
| Data payload | 8 | 0x14 | ID for no valid sensor data |
| 0x19 | ID for low battery voltage (VCC < 2.2V) | ||
| 0x64 | ID for temperature data (-55 to +125°C) | ||
| 16 | Signed integer | Temperature value (0.1°C resolution) | |
| 8 | Checksum | Checksum of ID and data payload as 2’s complement | |
| Total | 88 | — | Data telegram with Ttx = 11 ms at 8 kbit/s |
The remote sensor sends the acknowledgment protocol with the following data:
| Protocol Item | #Of Data Bits | Value | Description |
|---|---|---|---|
| Preamble | 55 | 1 | Pre-burst for wake-up and synchronization |
| Start bit | 1 | 0 | Start bit to indicate data payload |
| Data payload | 8 | 0x60 | ID for RSSI data |
| 16 | Integer | RSSI value (0-255) | |
| 8 | Checksum | Checksum of ID and data payload as 2’s complement | |
| Total | 88 | — | Data telegram with Ttx = 11 ms at 8 kbit/s |