MAX232 Serial TTL To 232 Shield for Arduino

Electronic equipment or module in the need to communicate with the world, often using serial communication mode, namely, by a series of binary coding data transmission. Based on SCM electronic equipment serial port is a big part of the use of the standard, it TTL level 1, level of logic is 5V 0V is logic 0 level, We used the PC serial use rs-five is 232C level standard, it is the logic 1 level 3V - - - the 12V, logic 0 level is + 3V ~ + 12 v. Because both level range far, and therefore must be in 232C rs-five and TTL circuit and logical relationship between the level of transformation, can in PC with this kind of electronic equipment serial communication between realization. Generally speaking, realize the transformation of the circuit can use division element, also can use MAX232 such integrated circuit chips.

We develop the electronic blocks is adopted, the serial port adapter MAX232 chip level conversion module can be easily Arduino in PC and establish serial communication. Arduino because of the scheme is USB turn serial, actual use if feel complex or not, can consider the stability of a string of product, due to the lack of a USB adapter turn this intermediate link, serial communication more directly. But now this module is only use the MEGA, and only Arduino COM1, COM2 in serial, COM3, reason is probably COM0 is directly connected with the USB chip, turn serial MAX232 between it and didn't seem to be very compatible.

Based on the use of electronic serial blocks are four core IIC/COM connections, using it can be easily connected serial port adapter Arduino MEGA special sensors to expand on the board, and the communication with Arduino:

With a serial line connecting PCS and serial port adapter, hardware connection is completed:

As part of the PC software, we can use in SSCOM such serial debugging tools, but the end is used below Arduino test code:

int val = 0;

void setup()
{
  Serial1.begin(9600);
}

void loop()
{
  val = Serial1.read();
  if (-1 != val) {
   if ('A' == val || 'a' == val) {
     Serial1.println("Hello from Arduino!");
   }
  }
}

The above code downloaded to perform after Arduino Arduino will come from the PC has been 
waiting for the order