MAX232

Abstract: The utility model discloses an intelligent voice drive control device of a wheel chair. A controller comprises a voice-frequency circuit module, a voice processing circuit module, a liquid crystal display module, an MAX232 communication module, a digital signal processor (DSP), a key circuit module, an operating rod circuit module, a power supply circuit module, a motor driving circuit module, a fault detection circuit module, a voltage and current detection circuit module and a braking circuit module. According to the intelligent voice drive control device of the wheel chair, a scheme of master-slave mode intelligent voice drive control of the wheel chair is put forward, and in the scheme, a single-chip microcomputer is taken as a voice information processor and the DSP is taken as a driving controller. A motor driving circuit adopts a special motor driving control chip IR2130, and an optocoupler isolation circuit is added between a power amplifying circuit and a control circuit so that system stability is improved. The intelligent voice drive control device of the wheel chair has the advantages of being controlled either in manual mode or in automatic voice control mode and being convenient to use.

Abstract: Communication via mobile phones is becoming increasingly common among humans but next in the pipeline is communication between human and robots. This project promotes wireless connectivity which makes it hassle free affair. In this paper we propose the concept of controlling a robot by a mobile phone from a remote area. The robot supports two ways of communication as it can receive commands by a mobile phone and in other way round it can send data through cell phone to the user. This prompted us to use a PC and its serial port with RS232 protocol. The user sitting at a distant place can send sms’s to control the robot placed far away from him (even in another continent). The sms is decoded in a PC by a program which then sends command to the robot via serial port. Similarly the robot can send information about the working environment condition received from its sensors. This data is converted to proper PDU or TEXT mode as needed by the mobile phone which is forwarded to the operator by a sms. This involves a NOKIA 6020 phone and an 8051 microcontroller (AT89C52). A RF module, connected to a computer’s serial port, can operate at two frequencies, one for communicating with the robot and another for the mobile. The cell phone’s TX and RX pins are connected to the serial port by the RF module and a MAX232 IC. The RS232 protocol does not support TTL logic so a line driver such as MAX232 has to be used to convert TTL logic levels to RS232 voltage level .The phone converses with the computer by AT commands sent through the serial port. A practical implementation of this project may witness applications such as home automation and security.

Abstract: The utility model relates to a small universal singlechip system capable of downloading based on a serial port. The appearance of the small system is a 10cm*10cm of rectangular circuit board. In the singlechip system, keyboard input, digital tube display output, a light-emitting diode, a USB power supply, an MAX232 (Maxim232), a 74LS244, a DB9 main joint, a resistor, a capacitor and an STC89C52 are connected according to electrical characteristics; a USB power supply switch is connected with a USB port and then is connected with a microcomputer through a port line; one end of the MAX232 is connected with the DB9 main joint, and the other end thereof is connected with a singlechip UART (Universal Asynchronous Receiver/Transmitter); and the other end of the DB9 main joint is connected with a downloading line. Singlechip programs can be directly downloaded by utilizing an ISP function in the STC89C52.