概述

　　便携式温湿度记录仪是具有内置温湿度传感器或可连接外部温湿度传感器测量温度和湿度的设备。便携式温湿度记录仪被广泛应用于食品、药品的运输和存储，一般使用电池供电，但市面上产品对于高性能和低功耗却很难做到统一。而本方案的便携式温湿度记录仪使用高性能、低功耗的MCU设计，可以实现对数据进行实时存储、TFT或LCD显示、USB导出和报警等功能。

　　优势

　　· Silicon Labs 32位低功耗EFM32LG系列MCU，集成TFT驱动、LCD和USB控制器，并提供文件系统FAT32参考工程，具有高集成度,减少产品BOM数量和开发难度。睡眠模式EM3功耗仅0.66uA，唤醒时间仅2us，超低功耗设计,非常适合低功耗便携设备的应用。

【EFM32LG】

EFM32LG Reference Manual

• 32-bit ARM Cortex-M3 processor running at up to 48 MHz

• Up to 256 kB Flash and 32 kB RAM memory

• Energy efficient and autonomous peripherals

• Ultra low power Energy Modes with Sub µ operation

• Fast wake-up time of only 2 µs

The EFM32LG microcontroller series revolutionizes the 8- to 32-bit market with a combination of unmatched performance and ultra low power consumption in both active- and sleep modes. EFM32LG devices consume as little as 211 µA/MHz in run mode.

EFM32LG's low energy consumption outperforms any other available 8-, 16-, and 32-bit solution. The EFM32LG includes autonomous and energy efficient peripherals, high overall chip- and analog integration, and the performance of the industry standard 32-bit ARM Cortex-M3 processor.

1 Energy Friendly Microcontrollers

1.1 Typical Applications

The EFM32LG microcontroller is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications. These devices are developed to minimize the energy consumption by lowering both the power and the active time, over all phases of MCU operation. This unique combination of ultra low energy consumption and the performance of the 32-bit ARM Cortex-M3 processor, help designers get more out of the available energy in a variety of applications.

Ultra low energy EFM32LG microcontrollers are perfect for:

• Gas metering

• Energy metering

• Water metering

• Smart metering

• Alarm and security systems

• Health and fitness applications

• Industrial and home automation

0 1 2 3 4

1.2 EFM32LG Development

Because EFM32LG use the Cortex-M3 CPU, embedded designers benefit from the largest development ecosystem in the industry, the ARM ecosystem. The development suite spans the whole design process and includes powerful debug tools, and some of the world’s top brand compilers. Libraries with documentation and user examples shorten time from idea to market.

The range of EFM32LG devices ensure easy migration and feature upgrade possibilities.

2 About This Document

This document contains reference material for the EFM32LG series of microcontrollers. All modules and peripherals in the EFM32LG series devices are described in general terms. Not all modules are present in all devices, and the feature set for each device might vary. Such differences, including pin-out, are covered in the device-specific datasheets.

2.1 Conventions

Register Names

Register names are given as a module name prefix followed by the short register name:

TIMERn_CTRL - Control Register

The "n" denotes the numeric instance for modules that might have more than one instance.

Some registers are grouped which leads to a group name following the module prefix:

GPIO_Px_DOUT - Port Data Out Register,

where x denotes the port instance (A,B,...).

Bit Fields

Registers contain one or more bit fields which can be 1 to 32 bits wide. Multi-bit fields are denoted with (x:y), where x is the start bit and y is the end bit.

Address

The address for each register can be found by adding the base address of the module (found in the Memory Map), and the offset address for the register (found in module Register Map).

Access Type

The register access types used in the register descriptions are explained in Table 2.1 (p. 3)

Features

3.3.1 MCU Features

• ARM Cortex-M3 CPU platform

• High Performance 32-bit processor @ up to 48 MHz

• Memory Protection Unit

• Wake-up Interrupt Controller

• Flexible Energy Management System

• 20 nA @ 3 V Shutoff Mode

• 0.4 µA @ 3 V Shutoff Mode with RTC

• 0.65 µA @ 3 V Stop Mode, including Power-on Reset, Brown-out Detector, RAM and CPU

retention

• 0.95 µA @ 3 V Deep Sleep Mode, including RTC with 32768 Hz oscillator, Power-on

Reset, Brown-out Detector, RAM and CPU retention

• 63 µA/MHz @ 3 V Sleep Mode

• 211 µA/MHz @ 3 V Run Mode, with code executed from flash

• 256/128/64 KB Flash

• 32 KB RAM

• Up to 90 General Purpose I/O pins

• Configurable push-pull, open-drain, pull-up/down, input filter, drive strength

• Configurable peripheral I/O locations

• 16 asynchronous external interrupts

• Output state retention and wake-up from Shutoff Mode

• 12 Channel DMA Controller

• Alternate/primary descriptors with scatter-gather/ping-pong operation

• 12 Channel Peripheral Reflex System

• Autonomous inter-peripheral signaling enables smart operation in low energy modes

• External Bus Interface (EBI)

• Up to 4×256 MB of external memory mapped space

• TFT Controller supporting Direct Drive

• Universal Serial Bus (USB)

• Fully USB 2.0 compliant

• On-chip PHY and embedded 5V to 3.3V regulator

• Integrated LCD Controller for up to 8×36 Segments

• Voltage boost, adjustable contrast adjustment and autonomous animation feature

• Hardware AES with 128/256-bit Keys in 54/75 cycles

• Communication interfaces

• 3× Universal Synchronous/Asynchronous Receiver/Transmitter

• UART/SPI/SmartCard (ISO 7816)/IrDA (USART0)/I2S (USART1+USART2)

• Triple buffered full/half-duplex operation

• 4-16 data bits

• 2× Universal Asynchronous Receiver/Transmitter

• Triple buffered full/half-duplex operation

• 8-9 data bits

• 2× Low Energy UART

• Autonomous operation with DMA in Deep Sleep Mode

• 2× I

2C Interface with SMBus support

• Address recognition in Stop Mode

• Timers/Counters

...the world's most energy friendly microcontrollers

2017-04-24 - Leopard Gecko Family - d0183_Rev1.2 7 www.silabs.com

• 4× 16-bit Timer/Counter

• 3 Compare/Capture/PWM channels

• Dead-Time Insertion on TIMER0

• 16-bit Low Energy Timer

• 1× 24-bit and 1× 32-bit Real-Time Counter

• 3× 8/16-bit Pulse Counter

• Asynchronous pulse counting/quadrature decoding

• Watchdog Timer with dedicated RC oscillator @ 50 nA

• Backup Power Domain

• RTC and retention registers in a separate power domain, available in all energy modes

• Operation from backup battery when main power drains out

• Ultra low power precision analog peripherals

• 12-bit 1 Msamples/s Analog to Digital Converter

• 8 input channels and on-chip temperature sensor

• Single ended or differential operation

• Conversion tailgating for predictable latency

• 12-bit 500 ksamples/s Digital to Analog Converter

• 2 single ended channels/1 differential channel

• Up to 3 Operational Amplifiers

• Supports rail-to-rail inputs and outputs

• Programmable gain

• 2× Analog Comparator

• Programmable speed/current

• Capacitive sensing with up to 8 inputs

• Supply Voltage Comparator

• Ultra low power sensor interface

• Autonomous sensor monitoring in Deep Sleep Mode

• Wide range of sensors supported, including LC sensors and capacitive buttons

3.3.2 System Features

• Ultra efficient Power-on Reset and Brown-Out Detector

• Debug Interface

• 2-pin Serial Wire Debug interface

• 1-pin Serial Wire Viewer

• Embedded Trace Module v3.5 (ETM)

• Temperature range -40 - 85°C

• Single power supply 1.98 - 3.8 V

• Packages

• QFN64

　　· Silicon Labs温湿度传感器Si702X，运行电流150uA，待机电流仅60nA,超低功耗。每片都出厂时校准，实现高精度的一致性。

【Si7020】

I2C HUMIDITY AND TEMPERATURE SENSOR

Features

> Precision Relative Humidity Sensor

》 ± 4% RH (max), 0–80% RH

> High Accuracy Temperature Sensor

》±0.4 °C (max), –10 to 85 °C

> 0 to 100% RH operating range

> Up to –40 to +125 °C operatingrange

> Wide operating voltage(1.9 to 3.6 V)

> Low Power Consumption

》150 µA active current

》60 nA standby current

> Factory-calibrated

> I2C Interface

> Integrated on-chip heater

> 3x3 mm DFN Package

> Excellent long term stability

> Optional factory-installed cover

》Low-profile

》Protection during reflow

》Excludes liquids and particulates

Applications

> HVAC/R

> Thermostats/humidistats

> Respiratory therapy

> White goods

> Indoor weather stations

> Micro-environments/data centers

> Automotive climate control and defogging

> Asset and goods tracking

> Mobile phones and tablets

Description

The Si7020 I2C Humidity and Temperature Sensor is a monolithic CMOS IC integrating humidity and temperature sensor elements, an analog-to-digital converter, signal processing, calibration data, and an I2C Interface. The patented use of industry-standard, low-K polymeric dielectrics for sensing humidity enables the construction of low-power, monolithic CMOS Sensor ICs with low drift and hysteresis, and excellent long term stability.

The humidity and temperature sensors are factory-calibrated and the calibration data is stored in the on-chip non-volatile memory. This ensures that the sensors are fully interchangeable, with no recalibration or software changes required.

The Si7020 is available in a 3x3 mm DFN package and is reflow solderable. It can be used as a hardware- and software-compatible drop-in upgrade for existing RH/ temperature sensors in 3x3 mm DFN-6 packages, featuring precision sensing over a wider range and lower power consumption. The optional factory-installed cover offers a low profile, convenient means of protecting the sensor during assembly (e.g., reflow soldering) and throughout the life of the product, excluding liquids (hydrophobic/oleophobic) and particulates.

The Si7020 offers an accurate, low-power, factory-calibrated digital solution ideal for measuring humidity, dew-point, and temperature, in applications ranging from HVAC/R and asset tracking to industrial and consumer platforms.

Functional Block Diagram

      【温湿度记录仪】

　　温湿度记录仪(Temperature and Humidity Data Logger)是温湿度测量仪器中温湿度计中的一种。其具有内置温湿度传感器或可连接外部温湿度传感器测量温度和湿度的功能。

　　早期的温度记录仪都是有纸类型的——即有纸温湿度记录仪。

　　随着计算机的普及和广泛应用，温湿度无纸记录仪产生，并因为其更准确地数据记录、更方便的数据存储、更便捷的数据分析功能，所占市场份额逐年猛增;带有USB接口的无纸温湿度记录仪更是极大的方便了数据的下载和保存。

　　近几年推出的U盘温湿度记录仪，使温湿度记录仪微型化达到了极致。而无线温湿湿度记录仪也使在某一区域内的多点温湿度记录和管理成为可能。

　　随着物联网和云技术发展，陆续有推出GPRS型实时上传数据的温度记录仪，用户可通过电脑浏览器或手机app随时随地查看数据、下载数据，当数据超限时用户还可以收到短信提醒。云存储的发展使得温度记录仪得到了质的提升，记录仪还增加了定位功能，基于基站定位，不但能记录温度还能指示设备的位置坐标，这一功能广泛用于冷链运输。