JPS59108164A - Trip computer - Google Patents

Abstract

PURPOSE:To switch distance units optionally only by one microcomputer by forming a processing program by kilometers and a processing program by miles independently and switching a distance unit alternation switch by an external input. CONSTITUTION:When an electric power supply SW5 is turned on and a microcomputer 6 starts to operate, the unit of a distance system is set up to mile by initizalizing. Subsequently, the travelling distance is found out by counting the number of pulses of a car speed sensor 3 and then a travelable distance is calculated from said travelling distance and fuel consumption and fuel remaining found from a fuel remaining sensor 1 and an A/D converter 2. When a unit alternating Sw4 is depressed once, a flag is set up in a memory 9 and the unit is turned from mile to kilometer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to switching display units of a trip computer, and particularly relates to a trip computer suitable for switching units such as travel distance and travelable distance.

[Prior art]

A typical function of what has traditionally been called a trip computer or drive computer for automobiles is the calculation and display of mileage and drivable distance, but the units of distance are Km and m.
It is divided into two parts, 1le, and is not unified worldwide. Therefore, depending on the destination, microcomputers must be configured separately for Km and m1le specifications, and in the United States, Europe, etc., KKm and m1le
This had the disadvantage that the calculations and composition were extremely complicated because the classification of the data changed in some places.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a trip computer that can change the unit of travel distance at any time using a single microcomputer.

[Summary of the invention]

In the present invention, a processing program for Km and a processing program for m1le are provided independently, a distance unit changeover switch is provided, and the above processing program is alternately passed through each time an external input by this distance unit changeover switch is received. By doing so, the unit of distance can be switched at any time using one microcomputer.

At this time, the unit display is also changed.

[Embodiments of the invention]

Examples of the present invention will be described below.

FIG. 1 shows an embodiment of the invention.

In the figure, interface l107, arithmetic control CP
Input/output is exchanged by a 4-bit microcomputer 6 that includes U8, storage devices R, OM, and RAM 9 in one chip. Input is fuel level sensor 1
The analog value of is converted by A/D converter 2,
There are a pulse signal from the vehicle speed sensor 3 and a signal from the unit switching SW 4, and the output is composed of a driver 10 for driving the display 11. The operation of the embodiment will be explained below. First, when the power SW 5 is turned on and the microcomputer 6 starts operating, initialization will cause the
Set the distance system unit to m1le.

After that, the traveling distance is calculated by counting the number of pulses of the vehicle speed sensor 3, and the previous traveling distance and the remaining fuel level sensor 1 are calculated.
, calculates the possible travel distance from the fuel consumption and remaining amount determined by the A/D converter 2. Next, when the unit switch SW4 is pressed once, a flag is set in the memory 9 in the microcomputer 6, and the unit is reset to m (from m1le), and from now on, the unit of distance traveled and the distance that can be traveled is equidistant. , 1 (m) is calculated and displayed. Each time the unit switch SW4 is pressed, the unit can be changed from m1le-+Km to m1le.The above-mentioned travel distance and possible travel distance are always calculated in both Km and mlle. It is assumed that the value remains in the memory 9.

FIG. 2 shows a processing time chart. In the figure, (A) is the remaining fuel amount acquisition processing timing, (B) is the switching input judgment timing, (C) is the display processing timing, (D
) indicate the arithmetic processing timing. In this way, since input determination processing is always included in one cycle of 7.8 m, either Km display or mlle display is determined, and subsequent calculation processing is performed in the determined unit, and display processing is also performed in the same manner as described above. It is done in units.

Therefore, according to this embodiment, the unit switching SW of the trip computer configured using a microcomputer is
Each time you press , the distance system is calculated and displayed.
K m − + m i le can be easily switched.

Another embodiment of the invention is shown in FIG.

The difference between this embodiment and the embodiment shown in FIG. 1 is that l-107
The Km fixed input signal is input to the Km fixed input signal, and Km is set at initialization so that unit switching by the changeover switch 4 can be canceled.

With this configuration, if the external input terminal A is set to HIGH, it is possible to switch between l(m and m1le), and if it is set to LOW, Km is fixed.This is because the embodiment shown in FIG.
The units of Km and m1le are switched by using a large external SW input, but it is not necessary to switch between Km and m1le when it is attached to cars for domestic use, and it is necessary to maintain the Km unit system. It is based on

Therefore, according to this embodiment, in addition to the effects of the embodiment shown in FIG. 1, Km can always be displayed at initialization.

〔Effect of the invention〕

As explained above, according to the present invention, the unit of mileage can be changed at any time using one microcomputer.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the invention, FIG. 2 is a processing time chart, and FIG. 3 is a diagram showing another embodiment of the invention. 1...Remaining fuel level, 2...A/D converter,
3...Vehicle speed sensor, 4...Unit switching SW, 5...
Power supply 5w16... Microcomputer, 7... Interface ■10.8... Arithmetic control CPU, 9.
...Storage device IM KaZzuno, 5 cells/

Claims (1)

[Claims] 1. In a trip computer that has a vehicle speed sensor that detects the vehicle speed and a fuel level sensor that detects the remaining amount of fuel in the gasoline tank, and that displays mileage etc. based on inputs from the two sensors, the distance system can be changed based on external input. A trip computer characterized in that the unit display can be switched.