101990984
Dragino LHT52 LoRaWAN Temperature & Humidity Sensor – Quick Reference & Datasheet Extract
(Dragino Technology Co., Ltd., Rev. 2022)

1. Device Identity1.1 Manufacturer P/N: 101990984 (internal SKU for LHT52-XXX complete sensor)1.2 Commercial name: LHT52 LoRaWAN Temperature & Humidity Sensor1.3 Description: battery-powered, Class-A LoRaWAN node with built-in TH sensor, external probe option, datalogging and alarm functions1.4 Firmware baseline: LoRaWAN v1.0.3 compliant, Class A operation1.5 Certifications: CE / FCC / RoHS (region-specific RF certifications depend on frequency variant)
2. LoRaWAN Frequency Ordering Matrix (suffix XXX)| Part number (101990984-XXX) | Region | Band (MHz) | Max EIRP | Duty-cycle | Notes | |-----------------------------|--------|------------|----------|------------|-------| | LHT52-EU433 | EU / Russia | 433.05 – 434.79 | 10 dBm | 1 % | | | LHT52-CN470 | China | 470 – 510 | 19 dBm | 1 % | | | LHT52-EU868 | Europe | 868 – 870 | 16 dBm | 1 % | | | LHT52-IN865 | India | 865 – 867 | 16 dBm | 1 % | | | LHT52-KR920 | Korea | 920 – 923 | 14 dBm | 1 % | | | LHT52-AS923 | ASEAN | 923 – 925 | 16 dBm | 1 % | | | LHT52-AU915 | Australia / LATAM | 915 – 928 | 30 dBm | 0.33 % | | | LHT52-US915 | North America | 902 – 928 | 30 dBm | 0.1 % | |
3. Environmental & Mechanical| Parameter | Value | Unit | Conditions | |-----------|-------|------|------------| | Operating temperature | –20 … +50 | °C | Li-SOCl₂ derating below 0 °C | | Storage temperature | –30 … +70 | °C | batteries removed | | IP rating | IP52 | — | splash / dust protected, indoor use | | Dimensions | 58 × 58 × 20 | mm | without batteries | | Weight | 42 | g | including 2 × AAA holder | | Mounting | wall-attachable | — | 2 × screw slots + 3 M adhesive pad | | Enclosure | ABS + PC, UV-stabilised | — | white, semi-matte |
4. Power Supply• Primary: 2 × AAA 1.5 V alkaline (LR03) or 1.2 V Ni-MH• Typical capacity: 1100 mAh @ 25 °C• Battery life: 3 … 5 years @ 15 min / day TX, 20 dBm, 25 °C (alkaline)• Low-battery threshold: 2.2 V (auto uplink)• Reverse-polarity protected, hot-swap capable
5. RF / Link Budget| Item | Specification | |------|---------------| | Radio chip | Semtech SX126x | | Max output power | +20 dBm (region-limited) | | Sensitivity | –137 dBm @ 250 bps, SF12 | | Antenna | built-in ceramic, 2 dBi peak | | Range (urban) | 2 … 5 km typical | | Range (LOS) | 15 km @ 20 dBm, SF12, 5 m height |
6. Built-in Sensor Performance| Parameter | Range | Accuracy | Resolution | Response | |-----------|-------|----------|------------|----------| | Temperature | –20 … +50 °C | ±0.3 °C (max) | 0.01 °C | t63 < 8 s | | Humidity | 0 … 99.9 %RH* | ±3 %RH (20-80 %) | 0.1 %RH | t63 < 8 s | *no condensation; sensor shuts down > 99.9 %RH to prevent drift.
7. Optional External Probe (order separately P/N AS-01)• Silicon encapsulated NTC, 2 m PVC cable, IP67• Accuracy: ±0.5 °C (–10 … 85 °C), ±2 °C (–55 … 125 °C)• Resolution: 0.0625 °C (16-bit ADC)• Automatically detected when plugged into USB-C port
8. LoRaWAN Protocol Stack• Class A only (RX1 = 1 s, RX2 = 2 s after TX)• Adaptive data rate (ADR) supported• Confirmed / unconfirmed uplink selectable via downlink• Port 2: temp + humidity + battery + alarm flags• Port 3: datalog download (up to 200 stored samples)• Port 5: configuration (interval, alarm thresholds, DR, TX-power)
9. Datalog Feature• Capacity: 200 records (rolling buffer)• Interval: same as uplink period (60 s … 65535 s)• Retrieval: LoRaWAN downlink Port 3, offset + quantity• Retention: data preserved during battery swap (< 30 s)
10. Temperature Alarm• High & low thresholds (–20 … +50 °C, 0.1 °C step)• Hysteresis: 0.5 °C fixed• Alarm transmission period: 15 s … 65535 s (separate from normal interval)• Alarm packets use highest data-rate for fast reception
11. Configuration Methods• LoRaWAN downlink (MAC-payload on port 5)• Local USB-C CLI (AT commands, 115 200 bps, 8-N-1)• Dragino “Sensor-Config” Android NFC app (future firmware)
12. LED Indicator (tri-colour)| Colour | Pattern | Meaning | |--------|---------|---------| | Green | 1 flash | Join success | | Red | 1 flash | Join fail / radio error | | Blue | 1 flash | Uplink sent | | Blue | 2 flashes | Alarm active | | Red | slow blink | Low battery (< 2.2 V) |
13. Default Factory Settings• Uplink interval: 900 s (15 min)• Data-rate: DR3 (SF9, 125 kHz)• TX power: max region-allowed• Temp alarm: disabled• ADR: enabled• Datalog: enabled
14. Firmware Upgrade• Interface: USB-C DFU (Device Firmware Update)• Bootloader: open-source, signed image• Average update time: 45 s @ 921 600 bps• Roll-back protection & CRC32 check
15. Compliance Summary| Region | RF | EMC | Safety | Environment | |--------|----|-----|--------|-------------| | EU | CE RED 2014/53/EU | EN 301 489-1/-3 | EN 62368-1 | RoHS, REACH | | US | FCC Part 15.247 | FCC Part 15B | UL 62368-1 | RoHS |
16. Packing & Logistics• Inner box: 20 pcs (anti-static tray)• Outer carton: 100 pcs (2 inner boxes)• Gross weight: 5.2 kg / 100 pcs• HS-code: 8517.62 (radio transceiver)• Country of origin: China