1, to achieve the communication between the MCU and the computer or its equipment. The function of the 232 chip is to realize the communication between the MCU and the computer or its equipment, because the MAX232 chip can convert the standard RS232 serial port level into the UART0V/5V level that the MCU can recognize and withstand, and realize the communication between the MCU and the computer or its equipment.
2, RS232 is an interface, is usually referred to as a serial port, RS232 interface communication to 12V voltage can be identified, but the high and low level of the relative high and low level of 12V and 0V, but 51 MCU high and low level of 5V and 0V, the level of 2 is not the same can not communicate, then the middle needs a level conversion chip to translate, MAX232 is used for this purpose. USB serial port refers to a device that can convert USB signals into serial signals.
3, max232 is a serial port of the computer rs232 signal level (-1010v) converted to the TTL signal flat (0, 5) chip used by the single chip, the price of this chip is more expensive about 6 yuan, below I will introduce the max232 pin diagram and max232 and computer serial port connection circuit, RS232 pin definition.
4, the functional components and functions contained in the MCU are mainly: cpu main chip (the device connected to expand through the bus) clock circuit (for the MCU to provide oscillating pulse) power circuit (for the MCU to provide power) internal data memory RAM (including general data register and special storageThe demand for localization and independent innovation is growing, and the domestic MAX3232 came into being. The domestic MAX3232 uses advanced technology and design, with performance and reliability comparable to international brands. It supports standard RS-232 level conversion, can operate stably in industrial environment, and has good anti-interference ability.
2, the domestic max3232 is a commonly used RS-232 conversion chip, which is widely used in serial communication equipment, such as computers, industrial control equipment, communication equipment, etc. This chip has the characteristics of stable performance, reliable quality and so onTo the favor of many manufacturers and users.
3, MAX3232CSE is a commonly used level conversion chip, used to achieve RS-232 standard serial communication. The chip is manufactured by Maxim and is part of the MAX3232 family.
4. The max3232 uses a proprietary low-voltage differential transmitter output stage that utilizes a dual charge pump to achieve true RS-232 performance at 0V to 5V power supplies. The device requires only four external 0.1uF charge pump capacitors. . The Max3232 ensures 120kbpsData rate while maintaining RS-232 output level. (2) MAX232 chip is a single power level conversion chip designed by MAXIM for RS-232 standard serial port.
2, ft232rusbuart driver is a serial port to usb driver for the software of the same name. The software operation is simple, you can convert the console port to usb, so that the pc through the usb port to connect to cisco routers, switches and other network devices, if necessary, you can personally experience. [Usage Instructions] Use driver ftdi_ft232_drive.exe, double-click to install, and then plug in the device will automatically recognize.
3, fly wire 232 chip : Using fly wire to connect the pin of the chip directly to the computer is a simple and direct alternative. The welding fly wire connects the pin of the chip to the corresponding interface of the computer (such as USB), which can realize programming and communication functions. Serial to USB chip: The serial to USB chip can be used as a replacement for the CH341A programmer. Chips such as FT232R and PL2303 can be connected to serial portsThe data is converted to USB data, so as to realize the connection with the computer.
4, level conversion with max23 because the MCU high level is 5 negative, but the computer 3 to 15 negative 0, -3 to -15 volts is 1, he is negative logic. The schematic diagram is as follows.
5, USB-Serial is a common interface converter used to convert Serial signals into USB signals. It is commonly used to connect communication between serial devices (such as digital devices, sensors, etc.) and computers. In the field of electronic engineering, USB-Serial is often used to program and debug various devices. A sense ofAn exclamation mark may be an expression of a problem or error with a USB-Serial device. This may refer to devices not being recognized, driver installation problems, communication errors, etc.
6, U disk directly inserted into the ARM board for data transmission: when the ARM board detects the U disk, it will jump out of a series of information, do not understand, do not know what it means, but this is not the focus, the focus is to see whether the information is: sda: sda1, or sdb: sdb1 such information, if there is, then this USB flash drive can be used.
1, MAX232 pin functions are as follows: 232 chip : Pin 1 232 chip : C1 pin 2: V Pin 3: C1-4: C2 pin 5: C2-6: V- 7: T2OUT 8th: R2IN 9th: R2OUT 10th: T2IN 11th: T1IN 12th: R1OUT Pin 13: R1IN Pin 14: T1OUT Pin 15: GND Pin 16: Vcc Attachment is the official data manual of the chip.
2, MAX232 and MAX202E chips are specially designed for the computer RS-232 standard serial port interface circuit, using 5v single power supply. The MAX232 and MAX202 pins are fully compatible, have basically the same functions, and can be replaced with each other. If you want to distinguish on the circuit board, but the working temperature is not the same. The internal structure can be basically divided into three parts: the first partIt's a charge pump circuit. It consists of 6 pins and 4 capacitors.
3, because the output voltage of the computer serial port is as high as 12V, the direct connection with the MCU will burn the chip. So MAX232 is used for level conversion. The MAX232 chip uses a single 5V power supply, and only a few external capacitors can complete the conversion from TTL to RS232 level, a total of two ways. A typical circuit is shown in the figure. It is only necessary to connect the RXD (0) and TXD (1) pins of the MCU.
4, chip quote: no piece 15 yuan or so, go to several company websites to see the quote, there areThe company's offer is quite high.
Demo model: Huawei MateBook X System version: win10 MAX232 chip is a single power level conversion chip designed by MAXIM for RS-232 standard serial ports, using a 5v single power supply. The MAX220MAX249 series line driver/receiver is designed for EIA/TIA-232E and V.28/V.24 communication interfaces, especially when not availableApplication of 12V power supply.
MAX232 is an RS232 compliant chip introduced by Texas Instruments (TI). It's used for level switching. The MAX232 chip is an interface circuit specially designed for the RS-232 standard serial port of the computer, using a 5v single power supply.
MAX232 is a level conversion chip, it converts the TTL level of the MCU to the RS232 level on the computer, RS232 level is negative logic, so there is the situation you said. Your virtual terminal should be placed in the output of the MCU and MAX232 is right.
max232 is a standard RS232 communication interface chip. On the one hand, the transmitted data of TTL level is converted to RS232 level and sent out, and on the other hand, the received RS232 level data is converted to TTL level. Usually, the TTL level end is a chip on the MCU or computer motherboard. The RS232 level end is generally the DB9 head, which is the COM port on the computer. Summary; Is to convert TTL level to RS232 level.
max232 is a serial port of the computer rs232 signalThe level (-10, 10v) is converted into the TTL signal flat (0, 5) chip used by the single chip, the price of this chip is more expensive about 6 yuan, below I will introduce the max232 pin diagram and max232 and the connection circuit of the computer serial port, RS232 pin definition.
1. You mentioned that the MAX232 chip has been replaced, is this to solve some problems?According to MAXIM's data sheet, the R1IN and R2IN inputs inside the MAX232 chip do connect 5KOhm's pull-down resistance to the ground. Therefore, if there is no driving signal at the R1IN and R2IN inputs, the R1OUT and R2OUT outputs should theoretically appear high. You ask if the MAX232 chip is faulty.
2, last night with max232cpe to do a RS232 level conversion board, used to download the program for the MCU. The connection of the chip refers to the values in the official documentation, using five 1uf polaritiesCapacitance. Made last night after a try can be used, download completely normal. After several attempts, it is sometimes found that max232 fever is very serious, but it can be connected again after the power failure, in short, the cause of fever can not be found, and fever is only once or twice by chance.
3. Have you changed max232? Because according to Maxim datasheets, the R1IN/R2IN input has a resistance of 5KOhm to the ground inside the chip. So, if the input of R1IN/R2IN is not driven, R1OUT and R2OUT should be the output highYes. Is max232 broken? PS, R1OUT and R2OUT direct short circuit is not good. At least a current-limiting resistor should be added between the two.
4, it should be done: the MCU should use a max232 to convert to RS232 interface, but it is recommended to use MAX202E, because the four capacitors with 104 can be used, so that four 104 chip capacitors can be used. TXD and RXD are connected to the TTL sending/receiving end of the MAX202E, and the sending/receiving end of the RS232 level of the MAX202E is the real RS232The interface is connected to the RS232 interface of other devices.
5, max232 is a computer serial port rs232 signal level (-10, 10v) into the TTL signal used by the MCU flat (0, 5) chip, the price of this chip is more expensive about 6 yuan, Next, I will introduce the max232 pin diagram and the connection circuit between max232 and the computer serial port, and the RS232 pin definition.
6, max232 is a serial port of the computer rs232 signal level (-10, 10v)Converted to the TTL signal flat (0, 5) chip used by the single chip, the price of this chip is more expensive about 6 yuan, below I will introduce the max232 pin diagram and max232 and computer serial port connection circuit, RS232 pin definition. Look at the picture below.