232 chip (232 chip pin definition)

• 1, A MAX232 can be connected to the string interface of two microcontrollers at the same time, and use the computer toTwo microcontrollers pass...
• 2, 232 chip always burn will the communication current is too large
• 3, MAX232 pin function

Can a MAX232 be connected to the string interface of two single chip computers at the same time, and use the computer to transmit to two single chip computers?

1. Yes. It's two aloneVertical serial channel, the interface is exactly the same, if you have two computers, you can use this circuit to download two single-chip computers respectively, do not interfere with each other.

2, direct connection definitely not. Use the jumpers, manually one at a time.

3, MCU and computer connection generally have the following: RS232 serial port connection, which is the most common connection. RS232-usb, which is becoming more and more popular. JTAG--JLINK--USB (RS232), mainly used for simulation, JTAG connects to the MCU, and then connects to the computer through the simulator.

4, a single chip microcomputer and a PC with a MAX232 can be. Because MAX232 can be bidirectional level conversion. And there are two roads in each direction. TTL to 232 and then TTL. The result with the MCU RXTX cross direct connection is no fundamental difference, the only advantage is: the two MCU can communicate at a distance.

5, the general use of single-chip serial communication can be. What signal is used for serial communication should be determined according to the actual situation. If the communication distance between the single chip microcomputer is far, RS485 communication mode can be used;If the communication distance between the microcontroller is close, the two microcontroller serial ports can communicate directly.

232 chip always burning will not be too much communication current

Generally, this type of equipment will integrate an isolated protection component at the time of design, in order to prevent the sudden connection of large current and high voltage. Even if the device is hit by a large current, the isolation protection module will be damaged for other components of the device.

I think it is normal, 232 serial port general driver (output)Up to 50mA of current, 20mA is nothing unusual.

Can be added in the computer serial port 232 photoelectric isolator to protect. First of all, the serial port itself does not support live plug, operation should pay attention to the second RS232 serial port burned, basically caused by the potential difference between the two interfaces. This is caused by the AC ground potential imbalance between the computer and the electronic scale, which is mainly easy to burn the serial port.

What you want to ask is the reason why the touch screen communication chip is always burning? The power supply is insufficient. According to a query on the Pacific Computer network. Touch screen communication due to low power supply voltagePin functions '>MAX232 chip pin functions The charge pump circuit consists of 6 pins and 4 capacitors. The function is to produce 12v and -12v two power supplies, the amount of 2 to ground and 6 to ground, greater than 7V, generally can meet the communication. Where 1 and 3 are applied 5V to 10V.

Connecting power: The MAX232 chip needs to connect 5V and GND power supply pins, as well as dual power supply VCC and VEE pins, where the VCC pin is connected to the 5V power supply and the VEE pin is connected to the negative power supply.

MAX232 chipWith a single 5V power supply, 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.