出租车计费器外文翻译中英对照.doc

Based on monolithic integrated circuits multi-purpose rental car mileage fare meters designAbstract: Introduced that one kind take monolithic integrated circuit A T89S52 as the core multi-purpose rental car mileage fare meters design, elaborates in the software and hardware design process key technologies processing. The simulation result indicated that this mileage fare meter has the collection idea regulation, the time, the cost, the memory, the examination, the statistics and so on many kinds of measurement functions, and has the overspeed reminder, to prevent the driver to cheat, the pronunciation, the printing and the demonstration and so on many kinds of functions. Compares with the existing system, this system has the overspeed reminder and so on a stronger function.1 introduction 1 introduction the rental car mileage fare meter is the rental car transport business charge special-purpose intellectualized measuring appliance, along with electronic technologys development, the rental car mileage fare meter technology unceasingly is also progressing and enhances. The domestic rental car mileage fare meter had already experienced 4 stage development. From the tradition completely the mechanical type which is composed of the mechanical primary device, namely replaces the part mechanical primary devices rental car mileage fare meter to half electronic formula with the electronic circuit; Again from integrated circuit type to present monolithic integrated circuit system design rental car mileage fare meter. The rental car mileage fare meter cost is whether accurate, the taxi driver whether overspeed is the passenger most issue of concern, but mileage fare meter transport business data management whether facilitates is the taxi driver most pays attention. How therefore to design one kind both to be able to prevent the driver to cheat effectively with overspeed and can facilitate drivers mileage fare meter especially important. Therefore, this article as the core designs a model of multi-purpose rental car mileage fare meter take monolithic integrated circuit A T89S52, this mileage fare meter can realize the course valuation and the demonstration, the data storage and the inquiry, the clock demonstrated that the overspeed reminder, the pronunciation disseminate news with functions and so on bill printing. It is more convenient than the market in some mileage fare meter use, function entire, but also has prevents the driver to cheat effectively with the system stability good merit. In which overspeed reminder function may remind the driver and the passenger, warned that the driver do not want to exceed the speed limit, avoids traffic accidents occurrence.2 System hardware structure and function characteristic2. 1 Overall planOverall plan design block diagram as shown in Figure 1, the overall system by monolithic integrated circuit The T89S52 control circuit, A44E Hall sensor electric circuit The T24C02 storage circuit, the DS1302 clock circuit, the ISD2560 pronunciation disseminates news the electric circuit, the bill marking circuit, the pressed key alignment circuit, the MAX7219 actuation display circuit and the power circuit is composed. The monolithic integrated circuit gathers and judges the spatial headlight signal and the distance examination sensor signal, when the rental car starts, the monolithic integrated circuit examines the Hall sensors signal impulse and carries on the course computation. When does not have the passenger, the monolithic integrated circuit transfers the real-time time chip DS1302 procedure and the MAX7219 serial port demonstration driver, carries on the clock demonstration with 4 L ED; The headlight breaks off when in the sky passenger loading: The ISD2560 pronunciation disseminates news the electric circuit to carry on the pronunciation to disseminate news 1 (welcome passenger to ride this rental car), through the DS1302 gain time information resolution daytime/the evening, then transfers The T24C02 procedure gain daytime/evenings unit price and the outset price, then starts information and so on valuation and tell time, course and amount; The headlight gets the passenger to get out in the sky time: Carries on disseminates news 2 (thanks rides this rental car once more, please hand over amount), and prints the good bill, the monolithic integrated circuit saves transport business data message to 24C02, waited for after the rental car starts once more, single information reset replacements and so on amount and course, complete a valuation in light of this.2. 2 Hardware circuit designBy the power unit, the Hall sensor distance survey part, the data demonstrated that the part, the clock part, the pronunciation disseminate news the part, the bill printing part and the data storage part and so on compose, various part of ports are separately connected with the monolithic integrated circuit AT89S52 outlet, realizes mileage fare meters function through monolithic integrated circuits control to realize.2. 2. 1 Power unitBecause mileage fare meters working conditions are quite bad, it requests to have the anti-vibration, the anti-high low temperature, anti-moist, abilities and so on anti-electromagnetic interference, when specially the power source aspects disturbance, like the rental car starts, the engine flame, the storage battery charge and so on create input the mileage fare meter + 12 V power sources not to be unstable. Therefore uses + 12 V storage battery power sources after the filter and the power source constant voltage management chip 7805 obtains + 5 V regulated voltage outputs, the guarantee overall system can the normal work.2. 2. 2 Distance survey partIn the rental car needs one to be able to obtain the wheel rotation is the distance measurement signal installment accurately, by obtains the standard signal impulse to send in the monolithic integrated circuit fixed time/counter T1 is P3. 5 pins, completes 100 time after monolithic integrated circuits T1 tally function counting have an interrupt to complete the distance the survey. (supposes wheel perimeter is 1 m, then the Hall sensor produces 100 the pulse then to express that every time vehicle traveling schedule 0. 1 km, has carried on establishment according to actual situation in procedure). The automobile shaft coupling according to the circle spacing inserting magnet steel, with Hall the sensor integration chip A44E examination and the output pulse, Hall sensor integration chip A44E has functions and so on signal conversion, voltage amplification, reshaping output, to increase its antijamming ability, passes through 74L S14 after the signal shaping the transmitted light occasionally sends in P3 again. 5 pins. But in this electric circuit to prevent the driver to make the shortcoming, may use the encryption sensors method, first counter impulse encryption which gathers to the Hall sensor, causes the cost pulse by the scrambled text way transmission, finally the decipher is the definite orders pulse, transmits to the mileage fare meter cost. In password sensor, what the encryption transmits to the decoder is the password, when the encryption and the decipher inherent password is the same, decoder only then to mileage fare meter transmission counter impulse, mileage fare meter only then cost, therefore, the password sensor enhanced the mileage fare meter cost reliability, the illegal taxi driver is also unable to make the fare to increase, simultaneously the driver cannot replace the mileage fare meter sensor secretly, realized the mileage fare meter to unify the installment, the service and the annual inspection global administration by the National Measurement Department.2. 2. 3 The data demonstrated the part, because the design requirements have the unit price (2), the midway standby period (2), the distance (4), the amount (4) to demonstrate that the clock (4) output, if uses LCD liquid crystal display, in is away from outside screen 1 m to be unable to see clearly the data, moreover cannot satisfy the request in daytime its contrast gradient, therefore uses 16 high luminance L the ED nixietube demonstration. When is the spatial vehicle hour, for the electricity saving, only the tell time, is for the driver examined that the time provides the convenience, when the driver wants to inquire the former transport business data, presses inquires the key to be possible to provide the demonstration; When passenger demonstrates transport business the unit price, the standby period, the distance, the amount and the clock. Demonstrated that driver MAX7219 has the serial input/parallel output function, most may demonstrate that 8 L the ED nixietube, simultaneously has may to brightness, the decoding way, the demonstration figure, the working pattern carry on the programming, very satisfied long-distance range data demonstration; MAX7219 selects the serial addressing method, enters the DIN end 16 serial bit data, in each CL K rise along is moved to the internal 16 shift register, in the LOAD ends rise along is locked saves to controls in the register and the data register, receives first is highest order D15, uses 89S52 in this electric circuit P1. 5 are the data mouth, P1. 6 are the LOAD end, P1. 7 last bell end. Because must demonstrate 16 L ED, therefore uses 2 piece of MAX7219 level company to carry on the actuation to demonstrate, previous piece of data outlet and next piece of data input port connection use. But on main circuit board TA89S52 output DIN, LOAD, CL K signal will transmit in display panels process possibly as a result to disturb has the distortion, will therefore carry on the reshaping then again transmitted light partner on the display panel circuit wafer to these 3 signals, will prevent the phenomenon occurrence which the data wrong the demonstration or did not demonstrate.2. 2. 4 Clock partThe mileage fare meter when the rental car spatial vehicle goes needs to demonstrate the real-time clock, because its clock takes daytime/an evening unit price automaticswitching datum, moreover mileage fare meters clock demonstrated that can provides the convenience for the driver and the passenger, therefore chooses a good clock chip to be very important to the mileage fare meter. DS1302 is one kind of high performance which, the low power loss real-time clock chip American DALLAS Corporation promotes, uses the SPI three connections and CPU carries on the synchronous communication; The clock may provide the second, divides, Japan, the week, the month and the year; Then through establishes DS1302 the control/condition register choice calendar, after the clock way undergoes the initial calibration, works the use; The working voltage width reaches 2. 55. 5 V, uses the double power source power supply (main power source and emergency power supply), and establishes the emergency power supply charge way, provided has carried on the brook thin electric current charge to the dorsal power source the ability, in has not advocated in power sources situation to begin using the emergency power supply to be able the retention time information and the data.2. 2. 5 The pronunciation disseminates news the part to consider mileage fare meters microminiaturization, the intellectualization, the speech chip uses the collectionCheng Dujiao high ISD2560 chip, its most major characteristic is uses E2PROM to carry on the analog information direct access, but does not need transforms its interior after A/D and D/A to have the transmitter amplifier, the automatic gain control clock, the speaker driving circuit and so on, uses + 5 V power source power supplies. The pronunciation module and monolithic integrated circuits connection as shown in Figure 8, designs in the process, will fix the pronunciation part (to board, to get out first terminology,) the information storage to the ISD2560 interior different beginning address. In transport business process acts according to the different service condition which on gets out to realize the different pronunciation function broadcast. When speech chip work, the system the first master routine transfer playback disposal procedure, seeks for in ISD2560 according to the pronunciation address the pronunciation unit, then delivers the signal the speaker to send out the sound.2. 2. 6 Bill printing partWhen the rental car arrives at the assigned location, the driver turns the spatial car license, then produces signal notice monolithic integrated circuit A T89S52, the monolithic integrated circuit starts the printing service the driving midway standby period, transport business course, the unit price, the amount, the date and data printings and so on vehicle time sells up and down rents a car the special invoice. This electric circuit selects the connection flapper method and the monolithic integrated circuit is connected, this characteristic causes mileage fare meters bill printing in the function with the main system integration, but when inspection, service may carry on alone. In this design uses micro to hit is the TP p216 miniature printer which EPSON Corporation produces, micro hits with the monolithic integrated circuit is connected through the parallel interface, when needs to print the data appears when printer I/O0I/O7, so long as STB changes to the low level from the high level, changes to the high level again from the low level, may send in the data the printer. By now the printer set at busily the BUSY line to (high level), forbids the recent data feeds; After the printer takes the data and processed finishes, the BUSY line set at to idly (low level), simultaneously sent out the responder pulse ACK notice system, might once more data-.2. 2. 7 The data storage partial data storage parts function is when the power source separates, memory current hypothesis unit price information. A T24C02 is a TMEL Corporations 2 kB electricity may clean the memory chip, uses 2 serial main lines and the monolithic integrated circuit communications, the voltage is lowest may to 2. 5 V, the nominal current is 1 mA, quiescent current 10Ua (5. 5 V), in the chip material may preserve above 40 years in the power failure situation, moreover uses 8 foots DIP seals, the easy to operate. Clock holding wire SCL and data line SDA needs external connection 5. 1 k on to pull the resistance, its function is reduces A T24C02 the static power loss, 24C02 uses the I2C main line and A T89S52 is connected, A T89S52 P1. 3 take its serial clock line, P1. 4 take its serial data line. When through established a time data after the pressed key to finish (for example: The day and nights unit price, the waiting time, rent the course, to rent the amount and so on), the system automatically transfers the stored routine, data message preservation in chip; When on system again electricity, the automatic transfer reads the memory procedure, memorys in data me