原标题：基于Semtech LORA SX1276 之智能禽舍气体检测应用方案

　　鸡舍通风降温管理非常重要，鸡?的体温高，呼吸快，代谢旺盛，呼吸时所需要的氧气和排出的二氧化碳是同等体重其它动物的2~3倍。另外，鸡粪在微生物、温度、相对湿度的作用下可产生大量有害气体，如氨气、硫化氢，使舍内空气不断受到污染。如果被污染的空气不能实时排出舍外，有害气体的浓度就会不断增加。

　　若能实时监控温度，有害气体，控制排气量，一来可以降低鸡只的生病机会，再来可以降低人力需求，此方案使用Semtech LORA超长距离的技术，可以将气体、温湿度监测等Sensor置于鸡舍各处，再由监控端判读数据，加以控制风扇遮帘等，并可长期存取相关数据作为饲养依据。

　　场景应用图

　　产品实体图

　　方案方块图

　　数据监控画面_1

　　数据监控画面_2

　　核心技术优势

　　使用气体侦测，温湿度监测等Sensor，再经由 LORA 无线技术传送信息，客户端再以LORA 无线技术控制风扇或遮帘，也可交由计算机自行控制以减低人力负担。

　　方案规格

　　1.Chipset: STM32L073xZ and SX1276

　　2.High performance ARM® Cortex® -M0+32-bit RISC core operating at a 32 MHzfrequency

　　3.Embedded memories (up to 192 Kbytes of Flash memory and 20 Kbytes of RAM)

　　4.LoRa Modem

　　5.+20 dBm constant RF output vs. Vsupply

　　6.Programmable bit rate up to 300 kbps

　　7.High sensitivity: down to -137 dBm

　　8.Excellent blocking immunity

　　9.FSK, GFSK, MSK, GMSK, LoRa and OOK modulation

　　10.Packet engine up to 256 bytes withCRC

　　11.Epoxy molding finished module in LGA type

　　12.Small footprint：13 mm x 11 mm x 1.1 mm

　　技术文档

      【Semtech SX1276】

　　137MHz to 1020MHz Long Range Low Power Transceiver

　　The SX1276/77/78/79 transceivers feature the LoRa® long range modem that provides ultra-long range spread spectrum communication and high interference immunity whilst minimising current consumption.

　　Using Semtech’s patented LoRa modulation technique SX1276/77/78/79 can achieve a sensitivity of over -148dBm using a low cost crystal and bill of materials. The high sensitivity combined with the integrated +20dBm power amplifier yields industry leading link budget making it optimal for any application requiring range or robustness. LoRa also provides significant advantages in both blocking and selectivity over conventional modulation techniques, solving the traditional design compromise between range, interference immunity and energy consumption.

　　Overview

　　Features

　　LoRa Modem

　　168dB maximum link budget

　　+20dBm - 100 mW constant RF output vs. V supply

　　+14dBm high efficiency PA

　　Programmable bit rate up to 300kbps

　　High sensitivity: down to -148dBm

　　Bullet-proof front end: IIP3 = -11dBm

　　Excellent blocking immunity

　　Low RX current of 9.9mA, 200nA register retention

　　Fully integrated synthesizer with a resolution of 61Hz

　　FSK, GFSK, MSK, GMSK, LoRa and OOK modulation

　　Built-in bit synchronizer for clock recovery

　　Preamble detection

　　127dB Dynamic Range RSSI

　　Automatic RF Sense and CAD with ultra-fast AFC

　　Packet engine up to 256 bytes with CRC

　　Built-in temperature sensor and low battery indicator

　　Applications

　　Automated Meter Reading

　　Home and Building Automation

　　Wireless Alarm and Security Systems

　　Industrial Monitoring and Control

　　Long range Irrigation Systems

　　Packaging

　　QFN 28

　　Order Codes

　　SX1276IMLTRT - Pb-free, Halogen free, RoHS/WEEE compliant product

　　【STM32L073RZ 】

　　Ultra-low-power Arm Cortex-M0+ MCU with 192 Kbytes Flash, 32 MHz CPU, USB, LCD

　　The ultra-low-power STM32L073xx 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 (up to 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.

　　The STM32L073xx devices provide high power efficiency for a wide range of performance. It is achieved with a large choice of internal and external clock sources, an internal voltage adaptation and several low-power modes.

　　The STM32L073xx devices offer several analog features, one 12-bit ADC with hardware oversampling, two DACs, two ultra-low-power comparators, several timers, one low-power timer (LPTIM), four general-purpose 16-bit timers and two basic timer, one RTC and one SysTick which can be used as timebases. They also feature two watchdogs, one watchdog with independent clock and window capability and one window watchdog based on bus clock.

　　Moreover, the STM32L073xx devices embed standard and advanced communication interfaces: up to three I2Cs, two SPIs, one I2S, four USARTs, a low-power UART (LPUART), and a crystal-less USB. The devices offer up to 24 capacitive sensing channels to simply add touch sensing functionality to any application.

　　The STM32L073xx also include a real-time clock and a set of backup registers that remain powered in Standby mode.

　　Finally, their integrated LCD controller has a built-in LCD voltage generator that allows to drive up to 8 multiplexed LCDs with contrast independent of the supply voltage.

　　The ultra-low-power STM32L073xx devices operate from a 1.8 to 3.6 V power supply (down to 1.65 V at power down) with BOR and from a 1.65 to 3.6 V power supply without BOR option. They are available in the -40 to +125 °C temperature range. A comprehensive set of power-saving modes allows the design of low-power applications.

　　主要特性

　　Ultra-low-power platform

　　1.65 V to 3.6 V power supply

　　-40 to 125 °C temperature range

　　0.29 μA Standby mode (3 wakeup pins)

　　0.43 μA Stop mode (16 wakeup lines)

　　0.86 μA Stop mode + RTC + 20 KB RAM retention

　　Down to 93 μA/MHz in Run mode

　　5 μs wakeup time (from Flash memory)

　　41 μA 12-bit ADC conversion at 10 ksps

　　Core: ARM® 32-bit Cortex®-M0+ with MPU

　　From 32 kHz up to 32 MHz max.

　　0.95 DMIPS/MHz

　　Memories

　　Up to 192 KB Flash memory with ECC (2 banks with read-while-write capability)

　　20KB RAM

　　6 KB of data EEPROM with ECC

　　20-byte backup register

　　Sector protection against R/W operation

　　Up to 84 fast I/Os (78 I/Os 5V tolerant)

　　Reset and supply management

　　Ultra-safe, low-power BOR (brownout reset) with 5 selectable thresholds

　　Ultra-low-power POR/PDR

　　Programmable voltage detector (PVD)

　　Clock sources

　　1 to 25 MHz crystal oscillator

　　32 kHz oscillator for RTC with calibration

　　High speed internal 16 MHz factory-trimmed RC (+/- 1%)

　　Internal low-power 37 kHz RC

　　Internal multispeed low-power 65 kHz to 4.2 MHz RC

　　Internal self calibration of 48 MHz RC for USB

　　PLL for CPU clock

　　Pre-programmed bootloader

　　USB, USART supported

　　Development support

　　Serial wire debug supported

　　LCD driver for up to 4x52 or 8x48 segments

　　Support contrast adjustment

　　Support blinking mode

　　Step-up converted on board

　　Rich Analog peripherals

　　12-bit ADC 1.14 Msps up to 16 channels (down to 1.65 V)

　　2 x 12-bit channel DACs with output buffers (down to 1.8 V)

　　2x ultra-low-power comparators (window mode and wake up capability, down to 1.65 V)

　　Up to 24 capacitive sensing channels supporting touchkey, linear and rotary touch sensors

　　7-channel DMA controller, supporting ADC, SPI, I2C, USART, DAC, Timers

　　11x peripheral communication interfaces

　　1x USB 2.0 crystal-less, battery charging detection and LPM

　　4x USART (2 with ISO 7816, IrDA), 1x UART (low power)

　　Up to 6x SPI 16 Mbits/s

　　3x I2C (2 with SMBus/PMBus)

　　11x timers: 2x 16-bit with up to 4 channels, 2x 16-bit with up to 2 channels, 1x 16-bit ultra-low-power timer, 1x SysTick, 1x RTC, 2x 16-bit basic for DAC, and 2x watchdogs (independent/window)

　　CRC calculation unit, 96-bit unique ID

　　True RNG and firewall protection

　　All packages are ECOPACK®2

　　电路原理图