基于MSP430单片机的流量显示表硬件CPU设计

随着计算机的发展,工业自动化水平的提高,在工程中流量显示表已得到了广泛的使用。显示仪表精确度的高低,直接影响着企业的经济效益。在我国现有经济水平下,使用单片机开发的流量显示表,在工程中是非常适用的。该表是用MSP430F135为主芯片,并辅以其他的外围模块构成的具有串行通讯功能,满足流量检测显示的嵌入式最小系统。     

Is there a slowdown in agricultural productivity growth in South America?

This article estimates agricultural productivity growth in 10 South American countries in 1969–2009 with the objective of investigating if the slowdown being measured in other countries is present in the region. Results show that productivity growth accounts for half of the three‐fold increase in agricultural output during this period and that performance is sensitive to R&D investments in the sector. The slowdown found for the 1990s to 2000s in the U.S. and some European economies does not seem to be present yet in South America. The region's total factor productivity (TFP) growth rate increased steadily from 1.07% during the 1970s to 2.29% during the 2000s. Given lags in adoption and the adaptive nature of innovations in these economies, we have yet to see the potential effects in South American agriculture of decreases in R&D in advanced economies.     

直流稳压电源及漏电保护装置设计

系统以MSP430F149单片机为主控电路。采用LM2599DC-DC升压电路和多个LM2940稳压,采集接负载电压、电流,通过单片机内部进行A/D转换,用LCD12864显示所测数值。系统由直流稳压电源电路、开关切换电路、漏电流保护电路、主控电路、显示电路构成。系统实现设计要求输出电压、电流;电压调整率小;负载调整率小;实时显示所测数值;漏电保护装置动作电路误差绝对值小、接入功耗小。     

一种低功耗无线传感器网络节点设计

利用Zigbee技术和嵌入式技术设计了一种以纺纱车间温湿度采集为应用对象的无线传感器网络节点,节点的软硬件均采用低功耗设计,可根据实际环境实现分布式安装。低功耗无线传感器网络节点设计具有无需布线、覆盖面广、安装调试方便和使用寿命长等优点,可广泛应用于纺织厂和烟草存储温湿度控制、环境监测、医疗护理等领域。     

MSP430F149单片机在电子血压计中的应用

时下,电子血压计与传统血压计相比有诸多优势,但因其准确性、重复性不太理想,使用受到很大局限。通过选用高性能硅压式传感器MPXV53GC6U,设计温度补偿电路,优化血压测量的控制计算方法,提高了系统的准确性、稳定性。选用功耗小体积小的器件,紧凑的系统构架,人性化的软件设计,使血压计轻巧便携、使用方便。并对该系统设计做了详细介绍。     

基于超低功耗单片机控制的物流运输状态检测系统的设计

为了解决精密仪器或易碎货物在运输过程中发生跌落冲击造成损伤或破碎以及由于包装不合理等原因导致对外界敏感仪器损坏的问题,设计了基于超低功耗单片机MSP430为核心的物流安全记录仪对整个运输过程进行实时监控。该系统利用美国ADI公司生产的三轴加速度传感器对运输过程中冲击事件进行实时采集捕获,采用瑞士SENSIRION公司生产的温湿度传感器对当前货物外部环境进行检测。     

Seasonal rural labor markets and their relevance to policy analyses in developing countries

Seasonality is a salient feature of rural livelihoods and particularly within agriculture the demand for labor varies with the seasons and weather. In low-income countries, agriculture employs almost two-thirds of the labor force and incomes from labor are a major determinant of welfare. Therefore, an appropriate model representation of rural labor markets is critical when analyzing agricultural and food policies. Economy-wide models are commonly used for ex-ante policy analysis, but have so far ignored the influence of seasonality, implicitly assuming separability of seasonal labor demand and supply. This study relaxes that assumption using a computable general equilibrium (CGE) model calibrated to the Bhutanese economy as an illustrative case. Using model setups with and without seasonal labor markets, a cereal export ban of India is simulated leading to higher import prices for Bhutan. Results demonstrate that neglecting the influence of seasons on rural labor markets systematically biases model results. Assuming homogeneity of labor units, i.e., allowing substitution across seasons, understates the impacts of policy changes on rural wage rates, distorts households' labor-leisure trade-off decisions and overstates agricultural supply response. Given the widespread use of economy-wide models, the results are important for understanding the implications of domestic and global policy changes for agriculture and welfare in developing economies.     

数字式电参数测试仪分析

本系统以MSP430F449为控制核心,由自动判别信号模块,测频模块,测电压、电阻、电流模块,LCD显示和键盘等模块组成。采用等精度法实现了频率的精确测量,通过分压网络实现了对电压的精确测量,通过将电阻、电流信号转换为电压信号实现了对电阻、电流的精确测量,且本系统可以自动识别所测信号。由于本系统充分利用了MSP430F449的内部资源,所以本系统功耗低,稳定性好,精度高,人机界面友好。     

一种新的高精度帆板倾角控制系统设计方案

给出了以MSP430F149为核心的帆板控制系统的基本原理与实现方案。该系统由倾角测量模块、电机驱动模块、显示模块、调节模块等组成。采用SCA103T倾角传感器,可实现倾角精确测量;采用直流电机驱动风扇。系统功能由按键控制,可对测量结果进行实时显示,人机交互界面友好,经测试,性能指标优良。     

简易LED图文显示系统

采用TI公司的MSP430F149单片机为控制核心,通过对32个三基色LED的亮灭和发光强度进行控制,设计了一种简单实用的LED图文显示系统。线性LED基座由电机带动高速旋转,利用人体的视觉暂留效应,形成完整的字符和图案,能达到很好的视觉效果。