IC card electronic voice book

The so-called "IC card electronic voice book", that is, reading the information in the IC card, and then converting it into sound information, to replace the electronic device of the existing book, for people who are not convenient for visual reading (such as the elderly, Used by blind people or patients, etc.).

At present, the capacity of IC cards sold in the domestic market can reach 500K bytes. For example, direct storage of voice signals (in 8K/sec sampling rate) can store about 62.5 seconds of direct voice information. Although the stored sound quality is better, it obviously cannot meet the requirements of the general book to borrow a large amount of information storage. The author stores the Chinese character's speech coding (custom), storing a Chinese character only takes 1.5 bytes (12 bits), then the 500K byte IC card can store no less than 333,000 Chinese characters, and can play nearly 30 consecutively. Hours are enough to meet practical requirements.

The design scheme given in this paper uses AT89LV51 single-chip microcomputer as the microprocessor, with ISD4004 as voice support, and AT45D041 type IC card as the electronic book information storage carrier. The AT45D041 IC card is a large-capacity memory card (4M bit) introduced by ATMEL in the United States in recent years. It is the largest IC card that is easily available on the market. With the advancement of technology, when switching to other types of IC cards with larger capacity, this design scheme still applies as long as the communication method is unchanged. Even if the method is changed, you only need to modify the design.

The basic working process of the device is as follows: First, the Chinese character text file (such as "The Romance of the Three Kingdoms") is converted into a voice code file and stored in the IC card (this work is done by the PC); then, when the IC card electronic voice book works The CPU in the playback device will read the speech code from the IC card; finally, the CPU then controls the ISD single-chip voice recording and playback circuit according to the code to play the corresponding voice.

This design scheme is an economical and practical electronic language book basic design scheme. Although it is not as good as the voice direct storage scheme in terms of sound quality, it has the advantages of low cost, small size, low power consumption and long continuous playing time.

1 hardware design

The electrical schematic of the playback device is shown in Figure 1.


Figure 1 IC card electronic voice book electrical schematic

There are 6 buttons in this design, which are "Broadcast" (BUTTON0), "Fast Forward" (BUTTON1), "Slow Forward" (BUTTON2), "Rewind" (BUTTON3), "Slowback" (BUTTON4) and "Stop" (BUTTON5).

In order to be able to resume playback from the last stop at the next boot, a data memory with power-down hold is required. The AT24C01A is used in this article.

In order to minimize the size and weight of the playback device, the device uses only one AA type (ie, No. 5) battery, so a step-up switching type regulated power supply is required. This article uses the MAX856. In order to save battery consumption, the device should have the function of automatic power off. When the "Play" button is pressed, the MAX856 chip 1 pin will be raised to a high level and the device will be powered. After that, the microcontroller sends a high-level pulse to the MAX856 chip 1 pin every 16 seconds to allow the device to continue to be powered. When the timing time (60 minutes) expires, the device stops sending a high level pulse to the MAX856 chip, and the device automatically powers down.

The main functions and technical parameters of the AT45D041 large-capacity IC memory card used in this design are as follows:

(1) has a serial interface compatible with SPI;

(2) 4325376;

(3) Low power consumption, dynamic current is 15mA, static standby current is 20μA;

(4) The maximum clock frequency is 10MHz.

Refer to the reference [1] for the pins and commands of the AT45D041 large-capacity IC memory card. In Fig. 1, pins 1 to 8 of IC_CARD correspond to pins 1 to 8 of AT45D041; 9 and 10 are auxiliary contacts of the IC card holder for detecting whether the IC card has been inserted.

The main functions and technical parameters of the ISD4004 voice chip used in this design are as follows:

(1) 16 minutes voice recording and playback, the minimum length is 200~400ms (this design uses 300ms);

(2) The maximum number of segments is 2,400;

(3) SPI interface mode.

The main pin of the ISD4004 voice core sleep and the connection method with the MCU are described as follows: AUD OUT--output audio signal, in order to get a larger output, use the power amplifier LM386 to amplify and provide it to the earphone or speaker. SS--chip select, active low, high between two instructions. MOSI--serial input, the main controller should put data to the local end half a cycle before the rising edge of the serial clock. MIS0--serial output. SCLK--Serial clock input, generated by the main controller, used to synchronize the data transfer between MOSI and MISO. The above four terminals are respectively connected to P1.7 to P1.4 of the single chip microcomputer. /INT--Interrupt, the local end is an open-drain output. When EOM or OVF is detected in any operation, the local end goes low and remains; RAC--row address clock, open-drain output, for storage management, connected to the P1.3 of the microcontroller.

2 Voice code file formation

The ISD4004 voice chip stores sounds in segments, one for each segment, and each tone is 300ms. However, it should be noted that many words have the same pronunciation (such as ye3: also, smelting, wild); while some pronunciations have no Chinese characters (such as: wai2, sai3, ka2, etc.). For each different sound, there are 5 basic sounds (ie, Yinping 1, Yangping 2, Shangsheng 3, Going 4 and Soft 5). As long as there is a Chinese character corresponding to it (the same pronunciation is only one), then a code is given, so that all the voice codes can be obtained. There are a total of 1311 pronunciations of Chinese characters. At the time of design, all the different sounds are arranged in English byte and vocal order. There are 1337 (1311 Chinese characters + 26 English letters) voice codes, that is, 1337 voices. With 1.5 bytes to store a voice code (that is, 1 Chinese character pronunciation), the 4M-bit IC card can store nearly 349,500 Chinese characters. After the voice code is determined, 1337 voices can be written in the order of the voice code in the ISD4004 voice chip.

First, according to GB2312-80, the conversion table of internal code and voice code of two-level Chinese characters is given, see Table 1. For each word in a given text file, you only need to find out its location code, then you can get the pinyin code by looking up the table, and finally write the phonetic code into the large-capacity IC card. For punctuation, treat it as a pause (no sound). It is worth noting that some Chinese characters (such as: and, he2, he4, huo2, huo4, hu2) have multiple pronunciations, and there will be multiple voice codes corresponding to these Chinese characters. If you want to convert to which voice code, you need to refer to the previous Chinese character or the latter Chinese character of the Chinese character. When it is still uncertain, the sound with the highest probability of occurrence (such as sum and he2) should be taken.

Table 1 Conversion table (fragment) of location code and phonetic code

The VB program is used to convert the text file in the computer into the voice code of the text and write it into the IC card, thereby forming an "electronic voice book". Different IC cards are loaded with different contents, ie different "books". Note that the contents of the IC card can be rewritten. After a book has been heard, you can also go to a special service point and exchange a new "book" to listen.

According to the scheme given in this paper, the volume of the IC card electronic voice book insertion and loading is about 120mm×80mm×14mm. The phonetic pronunciation of the device is slightly stiff. If the intelligent processing algorithm can be further introduced to make the connection between the pronunciations of Chinese characters softer, the sounding effect will be improved.

Wig Tape

This frontal lace blue liner tape has a hold time of 2-4 weeks, and could be longer depending on use. Perfect for wigs, toupees, and hair extension. Great wig liner tape bond even on outdoor sports.
Although it's clear that this double-sided tape has a good bonding strength and allows very natural movement, removing is just as easy. Take it off and clean up using any adhesive cleanser or alcohol.
Walker Lace Front Tape is also perfect for seamless hair extensions. It works well with front lace and no sweat can rip its heavy duty grip.
Here is pre-cut design in the middle of each hair extension tape, easier and more convenient for you to peel them off and apply, they will go well with your hair extension and invisible, make you hair look more natural, nice accessories for thin hair

Wig Bags,Silk Stain Wig Bags,Satin Drawstring Bag,Non-Woven Hair Extension Storage Bag With Hanger

Xuchang Le Yi De Import And Export Trade Co., Ltd. , https://www.lileaderbeauty.com