INTRODUCTION. What is the LSN50

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1 INTRODUCTION Dragino LoRa Sensor Node Dragino LoRa Sensor Node What is the LSN50 LSN50 is a Long Range LoRa Sensor Node. It is designed for outdoor use and powered by Li/SOCl2 battery for long term use power consumption and secure data transmission.it is designed to facilitate developers to quickly deploy industrial level LoRa and IoT solutions. It help users to turn the idea into a practical application and make the Internet of Things a reality. It is easy to program, create and connect your things everywhere. It is based on SX1276/SX1278 allows the user to send data and reach extremely long ranges at low data-rates.it provides ultralong range spread spectrum communication and high interference immunity whilst minimising current consumption.it targets professional wireless sensor network applications such as irrigation systems, smart metering, smart cities, smartphone detection, building automation, and so on. LSN50 uses STM32l0x chip from ST, STML0x is the ultra-low-power STM32L072xx microcontrollers incorporate the connectivity power of the universal serial bus (USB 2.0 crystal-less) with the high-performance ARM Cortex -M0+ 32-bit RISC core operating at a 32 MHz frequency, a memory protection unit (MPU), high-speed embedded memories (192 Kbytes of Flash program memory, 6 Kbytes of data EEPROM and 20 Kbytes of RAM) plus an extensive range of enhanced I/Os and peripherals. LSN50 is an open source product, it is based on the STM32Cube HAL drivers and lots of libraries can be found in ST site for rapid development. 1/17

2 STM32l0x The maximum link budget is 157 db +20 dbm, 100 mw constant RF output with Vsupply +14 dbm high efficiency PA Programmable bit rates up to 300 k High sensitivity: down to -137 dbm Bulletproof front end: IIP3 = dbm 89 db blocking immunity The low RX current is 10 ma and the register is held at 200 na Fully integrated synthesizer with 61 Hz resolution FSK, GFSK, MSK, GMSK, LoRa and OOK modulations Bit built-in synchronizer for clock recovery Synchronous word recognition Preamble detection 127 db + dynamic range RSSI Built-in temperature sensor and low battery indicator 1.65 V to 3.6 V power supply 2/17

3 Specifications MCU Side: MCU: STM32L072CZT6 Flash:192KB RAM:20KB EEPROM: 6KB Clock Speed: 32Mhz LoRa Side: LoRa Chip: sx1276/sx db maximum link budget. +20 dbm mw constant RF output vs. +14 dbm high efficiency PA. Programmable bit rate up to 300 kbps. High sensitivity: down to -148 dbm. Bullet-proof front end: IIP3 = dbm. 127 db Dynamic Range RSSI. LoRaWAN Specification Absolute Maximum Ratings: I/O pins: 0.5v ~ VCC+0.5V Common DC Characteristics: Supply Voltage: 2.1v ~ 3.6v Operating Tempature: -40 ~ 85 C I/O pins: Refer to STM32L072 datasheet Power Consumption: STOP Mode: 3.3v LoRa Transmit Mode: 20dBm 14dBm Battery: Li/SOCI2 unchargable battery Capacity: 4000mAh Self Discharge: <1% / 25 C Max continuously current: 130mA Max boost current: 2A, 1 second Dimensions: Size:65 x 50 x 50mm Net Weight: 140g Features STM32L072CZT6 MCU SX1276/78 Wireless Chip Pre-load bootloader on USART1/USART2 MDK-ARM Version 5.24a IDE I2C,LPUSART1,USB 2x12bit ADC, 1x12bit DAC 18xDigital I/Os LoRa Modem Preamble detection 3/17

4 Baud rate configurable CN470/EU433/KR920/US915 EU868/AS923/AU915 Open source hardware / software Available Band:433/868/915/920 Mhz IP66 Waterproof Enclosure Ultra Low Power consumption AT Commands to change parameters 4000mAh Battery for long term use Applications Wireless Alarm and Security Systems Home and Building Automation Automated Meter Reading Industrial Monitoring and Control Long range Irrigation Systems,etc. Getting Start Power On/Off the LSN50 The LSN50 is power off before shipping to avoid accident during shipping. We use a jumper to power on/off the LSN50, This will be useful for monitoring power consumption when connecting to different sensors and with different software. User can power on the device by simply adding the jumper to the board, as below. 4/17

5 Use the AT Command steps /17

6 3. Open application Seral port and click Start 6/17

7 You can see the status of the interface(if it does not appear, press the reset button or the AT command: ATZ.) 5. Input commands: Ex)AT+ADR=0(Adaptive rate is off).if your AT command is sent successfully, the software will receive feedback (OK). Tips:If you want to know the more commands,you can send: AT+?.) Program LSN50 Download Flashloader (Here is just sample application.you can also use the same type of programming application.and the method is similar.) and download STM32CubeExpansion_LRWAN.zip (Include source code). Steps Please follow the below of examples: Follow the picture to find the program file. Open this file. 7/17

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10 Result 10/17

11 Current consumption test in "Stop mode" mode Remove the jumper from JP2, connect with a multimeter, and hit 20uA. Pin Definition 11/17

12 Case Study 1: With Oil Sensor Schematic The Oil Sensor is a sliding variable resistance, floating through the float above the circuit to change the size of the resistance. 12/17

13 Connection steps 13/17

14 2/13/2018 Lora Sensor Node-LSN50 - Wiki for Dragino Project 14/17

15 Calculation method Only for our LSN50 such as: (TTN ) The value of the first two above is 00 00, which is 0 H = 0 * 3.0 * 1000 / (3.0 * 4095) (mm) If (TTN ) data = is 16 H = 16 * 3.0 * 1000 / (3.0 * 4095) (mm) Case Study 2: With DS18B20 Temperature Sensor Schematic DS18B20 Temperature range is -55~125. The delay time when the temperature changes is 750ms.Temperature measurement error is 0.5. The programmable resolution is 9~12 bits. Connection steps 15/17

16 Calculation method The DS18B20 is configured as 12 bits at factory shipment. When reading the temperature, a total of 16 bits are read. The first 5 bits are sign bits. When the current 5 bits are 1, the read temperature is negative. When the current 5 bits are 0, Take the temperature is positive. When the temperature is positive read method: the hexadecimal number can be converted into decimal. When the temperature is negative, the reading method is: add 1 after the hexadecimal inversion, and then convert it to 10 hexadecimal. Example: 0550H = +85 degrees, FC90H = -55 degrees. 16/17

17 Order Infomation Order Info- LSN50-XX-YY XX: YY: 433: Best Tuned at 433Mhz 868: Best Tuned at 868Mhz 915: Best Tuned at 915/920 Mhz 12: With M12 waterproof cable hole 16: With M16 waterproof cable hole 20: With M20 waterproof cable hole 17/17