Abstract: Introduced based on μPD78F0034 the monolithic integrated circuit and the module type structure’s rental car fare register’s hardware and the software design method, discussed μPD78F0034 monolithic integrated circuit’s main feature; Introduced this monolithic integrated circuit and the PC machine serial communication hardware connection method; Simultaneously gave has used the list, the double signal against to cheat the technology to prevent the fare register to cheat realizes the method specifically.
Key word: Rental car fare register; μPD78F0034; Serial communication; Against cheats the technology
Along with the rental car profession’s development, is also getting higher and higher to the rental car fare register’s request, the user not only requests the fare register stable property, the cost to be accurate, has against cheats the function; Simultaneously also requests it to have the ticket material printing, the IC card payment, the pronunciation telegraph and telephone, and functions and so on computer serial communication. Usually, designs the rental car fare register faced with the following three aspect question:
(1) different national and local cost way existence difference. Some areas have collect fees at night and the suburb charge and so on, but some local non-at night collects fees and the suburb charge; Even if the identical area, the different vehicle type’s rental car, its cost way also has the difference; On the other hand, the rental car also faces several years one time to adjust prices or questions and so on adjustment cost way. Therefore, designs the fare register not only need be able to satisfy different national and the local request, moreover the cost way’s adjustment must be very convenient.
(2), because the individual area has the special request to the fare register, sometimes must revise the software; Moreover, the fare register also faces software’s promotion; Therefore, designs the fare register ought to be able to program very conveniently.
(3) the fare register must have against cheats the function, can prevent the driver to cheat effectively; Simultaneously must prevent the fare register to halt in transport business process.
Therefore, the author has designed a section of fare register, has solved the above problem well. In this fare register established has reached 64 options, has covered majority national and the local rental car cost way nearly, therefore, time use did not need to change the fare register the hardware, but only need change the corresponding option material, then suitably in different country and area, and the cost material’s transmission might completes by the computer through the RS-232 serial port or the special-purpose handhold material transmitter, was convenient; Because used had the 32kB FLASH ROM monolithic integrated circuit μPD78F0034, therefore, time programming did not need to take down the monolithic integrated circuit from the circuit wafer, might carry on the programming directly to the monolithic integrated circuit; Moreover, this design also uses the list, the double signal against to cheat technical and the watch-dog electric circuit, solved the fare register to cheat well the phenomenon and halts the question. At present, this fare register obtained the widespread application in many big or media-sized cities.
in 1 system various modules hardware architecture
This kind with μPD78F0034 for master control component design’s fare register’s composition diagram as shown in Figure 1. The entire fare register system altogether is composed of five modules, respectively be the master control module, the pressed key display module, against cheats and the pulse input module, the connection module and the power source module.
1.1 master control modules
Master control module’s structure diagram as shown in Figure 2, in the chart monolithic integrated circuit for Japanese NEC Corporation μPD78F0034, this chip’s main feature is as follows:
when * the clock is 8.38MHz, the instruction cycle is 0.24μs;
●ROM is 32kB FLASH, RAM is 1024 bytes;
* the addressable space is 64kB bytes, some 5 external interrupt and 15 internal interrupts;
* has 39 CMOS I/O,8 the CMOS input and 4 N-CH drain electrode leads the way I/O;
* has 1 16 fixed time/counters and 2 8 fixed time/counters;
* has 1 clock timer, 1 watch-dog timer and 1 UART port;
* supports the I2C main line, may output the clock and the tone signal;
* the exterior data bus is 8, the internal register is 16;
* has 8 non-sign multiplication instruction and 16 division instructions;
* the working voltage scope is 1.8V~5.5V, has the STOP/HALT working pattern.
Thus it can be seen, this chip’s performance must surpass the present popular MCS-51 series, its 8 non-sign multiplication instruction and 16 division instructions have brought very big convenient for the software programming. When to μPD78F0034 programming, only needs its 5 pins, 3 pins in normal work time uses, as soon as therefore when designs the circuit wafer may these three pins do jumps the line switch; When programming, is connected these three pins and the programmer, when normal work, then on and circuit board’s part is connected. (Because this may not need μPD78F0034 to take down this monolithic integrated circuit from the circuit wafer to paste piece type seal, will take down will be very troublesome), but to its programming, namely will be directly programmable in the system, this method has provided enormous convenient for the development debugging and the later function revision and the software promotion. When this development, even does not have usefully to μPD78F0034 development system, but writes after PC machine the procedure, turns the binary code through the translation, then reads in directly through the programmer it μPD78F0034, then may debug the fare register each function. In addition 煾 more epiphysis stingy? Scull weapon mother inferior arc⒖Fault Ou Fangan twines mellow nie abstruse Sang Tingli the high-rising to punish the Egyptian enemy liquor to complete. The clock and the memory complete by chip DS1244Y. Through the option may establish whether to have the printing function, each kind of print command data passes to the fare register by PC machine through the RS-232 serial port or the handhold material transmitter and saves in DS1244Y. This fare register may use the driver card, the gathering card and the charge card three kind of IC cards, which kind of card uses to be possible to control by the option. Fare register through a I/O line control pronunciation interface circuit. When passenger loading, the monolithic integrated circuit delivered 50ms the low pulse to cause it for the pronunciation electric circuit to speak a few words. When the passenger gets out, the monolithic integrated circuit used 20ms the low pulse to cause the pronunciation electric circuit to speak another a few words.
1.2 connection modules
Shown in Figure 3 for the connection module constitutional diagram, it mainly by monolithic integrated circuit’s two I/O mouth, MAX232 and some resistance electric capacity and so on is composed. In the chart the resistance is 10kΩ, the electric capacity is 10μF; Monolithic integrated circuit’s P30 is the serial data receive foot, P31 is the serial data transmission foot, the correspondence baudrate supposes is 9600. In the chart, the MAX232 chip’s function is TTL which outputs the monolithic integrated circuit the level switch PC function receive 232 levels or PC machine the output 232 level switch monolithic function receive TTL level. The fare register or the handhold material passes on the number through the connection module and PC machine to carry on the serial communication, with the aim of establishing each kind of data which the fare register in each kind of parameter and the gathering fare register saves.
1.3 pressed keys and display modules
The pressed key and display module as shown in Figure 4, this module by 4 piece of 4511, 1 pieces of 4028, 1 piece of 2003, 20 nixietubes and some light emitter diode (achievement counts regulation, time charge indicating lamp) to be composed. The fare register has 6 functional keys, but in fact outward only then four pressed keys, respectively suppose are A, B, C, the D key. The spatial vehicle condition presses down the C key, the fare register enters carries passengers the module; The spatial vehicle condition presses down the B key, the fare register enters the connection module; The spatial vehicle condition presses down a key, the fare register enters the inquiry module, then presses a key upward to inquire, presses the D key downward to inquire. Another two function pressed key places in the fare register, with jumps line J1, J2 to indicate. When spatial vehicle condition, J1 short circuit, the fare register elimination saves all data; When fare register replacement, if J2 short-circuits, the fare register enters the material transmission module directly (this function mainly to prevent in fare register material disorder or new fare register do not have when material to enter endless loop).
1.4 against cheat and the pulse input module
Against cheats and pulse input module as shown in Figure 5. In order to enhance the fare register antijamming ability, the pulse input signal has selected the light pair method. Rental car’s pulse sensor usually has two kinds, namely single signal pulse sensor and double signal pulse sensor; What the so-called single signal pulse sensor refers to when is the rental car starts, has a holding wire output pulse signal; What but the double signal pulse sensor refers to when is the rental car starts, two holding wires the output amplitude is simultaneously same, phase opposite signal impulse. With this correspondence, against cheats the way to have the single signal against to cheat with the double signal against cheats two kinds. Actually to choose which kind, may jumps the line by the fare register in option and the hardware to decide.
a single signal against cheats principle of work
As shown in Figure 5, when the fare register after the option designated the single signal against cheats the way, jumps line switch B and A is connected, B and C separate, the monolithic integrated circuit causes the switch and K spot through P35 is connected. When has the pulse input, INT0 has an interrupt, the monolithic integrated circuit execution-interruption subroutine; Then causes the switch through P35 to separate with K, namely the turn-off pulse sensor’s power source, this time examines P36 the level, if for low, for normal, cheats the pulse for Gao Zewei. When cheats the pulse accumulates to the certain amount (this value after fare register parameter hypothesis), the fare register then recognized that has cheats the occurrence, therefore reports to the police, simultaneously produces a series of movement like fare, the idea regulation kilometer and counts the regulation time to reset completely or to deadlock the fare register and so on, actually to have what kind of movement, may decide by the option.
b pair of signal against cheats principle of work
When the fare register designated after the double signal against cheats, jumps line switch B and the C connection, B and A separates. When has the pulse input, INT0 has an interrupt, the monolithic integrated circuit execution-interruption subroutine, this time the monolithic integrated circuit must distinguish that P36 foot input signal whether is the low level, for low normal, otherwise to cheat the pulse. Other against cheat with the single signal time is the same.
1.5 power source modules
This module is a switching power supply, uses in the 12V direct-current power supply which will input becoming the stable 5V power source. Because the 12V power source’s provides by rental car on storage battery, has certain dispersivity, when especially the storage battery quality is not good, the 12V power source is low. But switching power supply’s applicable scope is broad, and driving force is strong, because therefore, uses the switching power supply to be possible to prevent the input voltage effectively each kind of breakdown which lowers produces.
2 software designs
This fare register’s software design is mainly composed of two parts; first, monolithic integrated circuit’s software design; second, PC machine software design. Because the two use the modulation design method, therefore, this program structure is clear, will be advantageous revises and the promotion from now on. In view of the fact that the length limit, below only introduces these two part of design cycle.
2.1 monolithic integrated circuit’s software designs
Monolithic integrated circuit’s software design flow as shown in Figure 6.
And the initialization module is composed of the hardware initialization and the software initialization two parts, the hardware initialization is mainly carries on the initialization to the monolithic integrated circuit and other related chips; But the software initialization is mainly symbolizes to each kind of software carries on the initialization, before simultaneously each condition data which preserves the power failure, reads in monolithic integrated circuit’s RAM; Then before the option decided whether can distinguish the driver card, as well as is returns to the spatial vehicle condition to return to carry passengers the condition which the power failure the fare register locates (for example the replacement option is 0 directly, then after fare register replacement, returns to the spatial vehicle condition directly; But when is 1, if before the power failure, the fare register is at carries passengers the condition, then after repositioning, returns to carry passengers the condition, if before the power failure, the fare register is at must carries passengers the condition, then after repositioning, returns to the spatial vehicle condition directly). In chart each module is composed of many submodules, like carries passengers the module to contain counts the regulation cost, the time cost, the printing ticket, the suspension, the guest inferior data to read in the RAM medium submodule; But inquires includes the inquiry to accumulate at the same day the data, the total cumulative data and the guest inferior record small steelyard module. Each module may return to the spatial vehicle module through the pressed key (in chart not to draw).
2.2 PC machine software designs
Because VB6.0 has serial communication MSComm (telephone box) to control to come to provide the serial communication for the application procedure, and has the good user interface and the simple convenience serial communication function, therefore, does not need to borrow other languages to be possible to develop the outstanding correspondence software. The PC machine software is mainly composed of the following several modules: The cost material revision and the transmission, the print command data revision and the transmission, the option data revision and the transmission, gathering accumulate, pick the lump to accumulate and to gather the guest inferior record at the same day and so on (as a result of length limit, here has not given program flow diagram). Because in the software established under has pulled the type menu and each kind of control push-button, therefore, directly or under pulled the type menu with the mouse click control push-button then to complete the corresponding operation (certainly, might also through press down quick key to realize). The cost material, the print command data and the option data respectively save in a text document; In addition, this software has also established each kind of password, may prevent the irrelevant personnel illegal revision data.
when 3 designs should pay attention question
This fare register’s option reaches 64 much, the function is complete, can meet the different local need, but the software programming and the debugging are also quite complex, needs specially carefully. In order to enable the fare register to stabilize, to work reliably, carries on when the software and hardware design must pay attention to the following several points:
(1) to prevent the fare register to halt, the software programs when should use the instruction redundant technique, the software trap technology as well as the software watch-dog technology. Some interests may consult the reference.
(2), because the driver card, the gathering card, the charge card use in common a IC card connection, therefore, the master control module wants the caution area branch customs station the type, should defer to the IC card the related control command correct programming.
(3) does not use the IC plug as far as possible. Because the IC plug has the big distributed capacity, therefore, should weld directly IC on the printed wiring board. Each IC should add a decoupling electric capacity, the decoupling electric capacity’s must be as far as possible short on printed wiring board pin. Moreover, quartz crystal’s outer covering must earth.
(4), because the fare register uses the switching power supply, therefore, time design must first in switching valve’s C, the E interelectrode add the RC absorbing circuit. And adds the RC absorbing circuit in two rectification return route’s rectification diode both sides to suppress the surge voltage. Second must thicken between the switching valve and the radiator fin insulation spacer thickness, reduces between the switching valve and radiator fin’s coupling capacity. Third must use the power source filter. Because joins the filter in power source’s input end to be possible to suppress input end’s transient state disturbance; Direct-current power supply’s out-port must turn on the condenser filter, by output voltage’s ripple limit based on this, simultaneously will suppress the pulse interference which the digital signal produces. Fourth should also use the shield measure to further reduce switching power supply’s disturbance.
4 concluding remark
Because this fare register’s design has used the function very strong monolithic integrated circuit μPD78F0034, the power source monitoring and watch-dog chip MAX705 and the list, the double signal against cheats the technology, thus basically ceased the rental car the fare register to halt the phenomenon in transport business process and cheats the phenomenon. Looking from the service condition, this fare register stability is good, the reliability is high, the percentage of products sent back for repair is very low. Moreover, because has used the module type structure and in the system programmable method, therefore, its software’s revision and the promotion are also convenient.
