DD230973A1 - MANY SENSOR INPUT FOR DATA AND COMMANDS WITHOUT USING SPECIAL SENSOR CIRCUITS - Google Patents

Abstract

It shows a multi-digit sensor input for data and commands without the use of special sensor circuits for manual input with different data width mainly in EDVA and controls of NC machines, industrial robots and consumer goods. The aim of the invention is to avoid the disadvantages of using mechanical contacts as controls, using the advantages of Beruehrungsflaechen as sensors, bypassing the high cost, which arises when many controls are required and to find conventional sensor circuits use. The task was solved by the fact that the sensors serving as input devices are activated one after the other whenever the character belonging to the sensor and generated by a binary counter is applied to the circuit output. The counter is driven by a clock generator which is stopped by a threshold switch when a sensor is touched while passing through its active phase. The sensors are activated by the outputs of a 1-out-of-n decoder, which decodes the counterthread constantly. The contact bounce occurring with mechanical buttons can not occur due to the circuit. figure

Description

Fields of application of the invention

Applications for the inventive circuit arise wherever data and commands in EDVA electronic typewriters, microcomputers, noiseless teleprinters with screen, consumer electronics, NC controllers, etc. must be entered.

Handhelds for remote controls, portable equipment for capturing material in large inventory, teach-in controls for industrial robots also require light-weight and secure keypads such as modern electronic measuring and testing equipment

Not applicable is the circuit described here in a very high humidity environment.

Known technical solutions

For entering data and control commands by hand usually key switches or with a small amount of input points also touch keys (Sensorsn) are used. Disadvantages here are the wear on mechanical buttons, contact uncertainties especially with small currents and occurring switching noise Known sensor inputs switch noiseless, reliable contact and wear, but require a larger number of sensors high component cost especially on special sensor circuits Also consuming are sensors that exploit magnetic fields

Object of the invention

While avoiding the above-mentioned deficiency, the bit combinations, from which data and commands to be entered, can be formed accurately and with little effort, the operating speed should be possible in the manually realizable limits, without causing high input sequence systemic errors arise basis a 4-bit wide (half-byte) hexadecimal input, which can be arbitrarily ranked side by side for wider Datenwor + e without the effort in the realization increases to the same extent.

Essence of the invention

It is the technical task to solve the bit combinations generated by a binary numerator then provide at the output of the circuit, if one of the respective combination corresponding sensor touches wira The technical solution is realized so that cycled through a binary counter driven by a clock payer and a downstream decoder Each decoder output activates the contact surface of a sensor corresponding to the character represented by the payer The corresponding other halves of all contact surfaces are connected to each other and to the input of a threshold switch The output of the threshold counter stops with logical L the clock generator or closes one between this and the payer input gate circuit. However, this only happens when the input of the threshold switch, which has a high impedance to logical H, is pulled to logical L. This condition is achieved by touching a sensor, electrically connecting its two halves via the skin resistance of the finger. Is the sensor activated by the associated decoder output? (Logically L), the bit combination will persist for the time the sensor touched the payer outputs and will be overwritten by the slave device.

From the L output of the threshold switch, the data valid signal for the slave device can be derived. In some applications, setting a static flip-flop forces the stop of the clock generator until the flip-flop is reset by an acknowledgment signal (also generated automatically) For example, in the application of the S-circuit for telex keyboards, the FF is reset by a parallel-to-senen converter required here

embodiment

The example shown shows the basic principle of the invention based on a hexadecimal input circuit bet 2 kHz clock frequency each of the 16 sensors 125 times per second for about 30 microseconds activated The overall circuit consists of the clock generator 1, the payer 2 with nachgeschlatem decoder 3, the contact surfaces 4th and the threshold switches 5 and 8

The payer 1 with start-stop device 6 was realized here with an IS D 100. Its clock frequency is about 2 kHz. Sem output signal switches the payer 2 (IS D 193) cyclically forward-paying from 0 to F (hexadecimal) The payer output provides the output signal 7, which is simultaneously present at the decoder 3. The decoder 3, realized by an IS K 155 ID 3 (SN 74154) , decodes continuously the output signal of the counter 2 and switches the input assignment corresponding output to logical L The 16 outputs of the decoder 3 go to the 16 contact surfaces, each other halves to each other and to the input of the threshold switch 5 (IS A 302) are all 0.5 milliseconds another decoder output is switched to logical L.

253 108 4

The input of the IS A 302 is above a resistance of greater than 1 Mohm at the operating voltage of + U deep B = 5 volts and thus logic H.

If this is bridged by touching a sensor surface pair of this lower than 1 MOhm, the input of the threshold switch 5 is pulled to the logical L in the moment in which the associated decoder output has switched to logic L. The open-collector output of the threshold switch follows the input and its L signal at the output stops the clock generator 1. The counter 2 remains at its count and its output shows the bit combination that corresponds to the sensor touched binary (eg. HLLH when touching the sensor 9).

From the output of the threshold switch 5, a data valid signal can be derived as a write-in command for the slave device. In the example shown, the output signal 7 of the counter 2 is maintained until after the control of 7, the sensor Q (= acknowledgment) is touched and the counter 1 is restarted via the threshold value switch 8. The hexadecimal sensor input is used here to program static 1-kBit memory U 202 in half-byte width. Since only one sensor is activated by the decoder at a time, character mutilation by accidentally touching more than one sensor is not possible at the same time. Only the first-touched sensor will always be able to switch the threshold value switch 5.

The example shown clearly shows that phenomena that are due to the contact bounce when entering with mechanical buttons and force there to special measures, can not occur here circuit due.

The basic principle described above is expandable. Thus with two decoders SN 74154 with 5 bit data width 1 from 32 can be decoded. That gives 32 dependent sensors. With even greater number of dependent sensors of the second decoder is used to activate the threshold, so that at 8-bit data width 256 dependent sensors would be possible.

If sensors can be operated at the same time, they are divided into groups and each group is assigned a threshold value switch (character, position and function sensor). However, except for alphanumeric input with 64 characters, you will fall back to hexadecimal notation for larger data widths and string these nibbles in the correct position. A special modification is the simultaneous use of the sensors. In this case, the clock generator is not stopped; the counter runs so constantly. The sensors are constantly polled from 0 to η and thereby determined occupied.

In the example of a chess computer, the playing field would be designed as a sensor surface which occupies figures on the base surface with conductive material. Since the chess pieces at the start of the game occupy a defined position for place and value, a continuous query is possible throughout the game, without the player inputs his moves by hand. Of course, he also has to add the figures issued by the computer to the figures. The small example was intended only to illustrate the simultaneous use of the sensors.

Claims (5)

253 108 4 Invention claim: 1 Multi-part sensor input for data and commands without the use of special sensor circuits characterized by the fact that the use of contact surfaces (sensors), the disadvantages of mechanical Tastenadze be avoided 2 Sensors provide secure data entry, characterized by the fact that only one sensor of each group is activated for input. 3 The character corresponding to the output signal is always bounce-free and free of spikes, characterized by the fact that, due to the circuit, the character belonging to the respective sensor must first be present exactly at the payer output before the corresponding sensor can be activated at all via the decoder output 4 Gei inger circuit complexity compared to conventional technical solutions even with a large number of sensors, characterized in that no special sensor circuits such as U 710/711 or U 705 are used An essential feature of this invention is characterized in that with the same large number of input points, even with any arrangement of the same, over the prior art, the inventive production of data input units is more economical For this 1 page drawing