Pattern-MAC (PMAC) protocol, instead of having fixed sleepwakeups,
the sleep-wakeup schedules of the sensor nodes are
adaptively determined. The schedules are decided based on a
node’s own traffic and that of its neighbors.
Commercially available active noise control headphones rely on fixed analog controllers to drive "anti-noise" loudspeakers. Our design uses an adaptive controller to optimally cancel unwanted acoustic noise. This headphone would be particularly useful for workers who operate or work near heavy machinery and engines because the noise is selectively eliminated. Desired sounds, such as speech and warning signals, are left to be heard clearly. The adaptive control algorithm is implemented on a Texas Instruments (TI™ )
1
TMS320C30GEL digital signal processor (DSP), which drives a Sony CD550 headphone/microphone system. Our experiments indicate that adaptive noise control results in a dramatic improvement in performance over fixed noise control. This improvement is due to the availability of high-performance programmable DSPs and the self-optimizing and tracking
capabilities of the adaptive controller in response to the surrounding noise.
·詳細(xì)說(shuō)明：DTMF檢測(cè)程序。定點(diǎn)計(jì)算，可移植到DSP上。 Usage: dtmf filename -DTMF examination procedure. The fixed point calculation, may transplant to DSP on. Usage: Dtmf filename 文件列表: alaw.cpp alaw.h &nb
Abstract: A laser module designer can use a fixed resistor, mechanical pot, digital pot, or a digital-to-analogconverter (DAC) to control the laser driver's modulation and bias currents. The advantages of a programmablemethod (POT or DAC) are that the manufacturing process can be automated and digital control can be applied(e.g., to compensate for temperature). Using POTs can be a more simple approach than a DAC. There can be aslight cost advantage to using a POT, but this is usually not significant relative to other pieces of the design.Using a DAC can offer advantages, including improved linearity (translating to ease of software implementationand ability to hit the required accuracy), increased board density, a wider range of resolutions, a betteroptimization range, ease of use with a negative voltage laser driver, and unit-to-unit consistency
Abstract: This article discusses application circuits for Maxim force/sense digital-to-analog converters (DACs). Applications include:selectable fixed-gain DAC, programmable gain DAC, photodiode bias control, amperometric sensor control, digitally programmablecurrent source, Kelvin load sensing, temperature sensing, and high current DAC output. A brief description of the various DAC outputconfigurations is also given.
Abstract: This application note illustrates an intermediate 8V switching power supply for an automotive radio and infotainment system.The design withstands the complete automotive input voltage range (including cold crank and load dump conditions), assuring a stable8V supply for common subsystems such as a CD driver, LCDs, and a radio module in modern infotainment systems. To avoiddisturbance in the AM and FM bands, the switching power supply runs at a fixed frequency of 2MHz, enabling an ideal solution forradio systems.
Features: High efficiency, high reliability, low cost AC input range selected by switch 100% full load burn-in test Protections: Short circuit / Over load fixed switching frequency at 25KHz Cooling by free air convection 1 year warranty Dimensions: 199*98*38mm (L*W*H)
設(shè)計(jì)了一種基于PIC16C71單片機(jī)的數(shù)字水溫配制閥。該配制閥采用NTC熱敏電阻作溫度傳感器，與固定電阻組成簡(jiǎn)單分壓電路作為水溫測(cè)量電路，利用PIC16C71單片機(jī)內(nèi)置的8位A/D轉(zhuǎn)換器把熱敏電阻上的模擬電壓轉(zhuǎn)換為數(shù)字量，PIC16C71單片機(jī)控制直流電機(jī)驅(qū)動(dòng)混水閥調(diào)節(jié)冷熱水的混合比例實(shí)現(xiàn)水溫調(diào)節(jié)。給出了控制電路圖，對(duì)水溫測(cè)量電路的參數(shù)選擇和測(cè)溫精度作了詳細(xì)討論。實(shí)驗(yàn)和分析表明，選用阻值較大的NTC熱敏電阻和分壓電阻可較好地解決熱敏電阻因功耗較大造成的熱擊穿問(wèn)題。
Abstract:
A digital valve for controlling water temperature based on PIC16C71 was presented in this paper.A bleeder circuit which consisted of a NTC thermistor as temperature sensor and a fixed resistance was designed as water temperature measuring circuit.The analog voltage on the thermistor was converted into digital signal by a 8-bit A/D converter embedded in PIC16C71. Based on the digital signal， the MCU PIC16C71 drived the valve by a DC motor to adjust the water temperature through adjusting the proportion of hot water and cold water.The circuit diagram of controller was given，the principle，the component parameters and the accuracy of measuring temperatures were also dissertated in detail. It was found by experiment and analysis that thermal breakdown of thermistor caused by high power could be solved by selecting thermistor and fixed resistance with high impedance value.
為提高電容測(cè)量精度，針對(duì)電容式傳感器的工作原理設(shè)計(jì)了基于PIC16LF874單片機(jī)電容測(cè)量模塊。簡(jiǎn)單闡述了電容測(cè)量電路的應(yīng)用背景和國(guó)內(nèi)外研究現(xiàn)狀，介紹了美國(guó)Microchip公司PIC16LF874單片機(jī)的特性。電容式傳感器輸出的動(dòng)態(tài)微弱電容信號(hào)通過(guò)PS021型電容數(shù)字轉(zhuǎn)換器把模擬量數(shù)據(jù)轉(zhuǎn)換成數(shù)字量數(shù)據(jù)，所測(cè)數(shù)據(jù)由PIC16LF874單片機(jī)應(yīng)用程序進(jìn)行處理、顯示和保存。實(shí)驗(yàn)結(jié)果表明，固定電容標(biāo)稱值為10~20 pF 的測(cè)量值相對(duì)誤差在1%以內(nèi)，同時(shí)也可知被測(cè)電容容值越大，測(cè)量值和標(biāo)稱值相對(duì)誤差越小。
Abstract:
To improve the accuracy of capacitance measurement，aimed at the principle of work of mercury capacitance acceleration transducer，the design of micro capacitance measurement circuit is based on the key PIC16LF874 chip. Briefly discusses the application of the capacitance measuring circuit for the background and status of foreign researchers，focusing on the United States PIC16LF874 microcontroller features. Capacitive sensor outputed signal through the dynamics of weak PS021-chip capacitors （capacitancedigital converter） to convert analog data into digital data，the measured data from the PIC16LF874 microcontroller application process， display and preservation. Experimental results show that the fixed capacitor 10pF ~ 20pF nominal value of the measured value of relative error is within 1%，but also it canbe seen the value of the measured capacitance larger，measuring value and the nominal value of relative error smaller.
