Lesson 23--Microduino "Serial port receives string and translated into an array"

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Objective This lesson will show to how to translate the string received from serial port into an array and then use these data to control LED. For example, the serial port received data "100,200,300,400,500,600", then output the PWM by port 3,5,6,9,10 they are the PWM output port on Microduino. Equipment Microduino-Core Microduino-FT232R Other hardware equipment Breadboard Jumper one box Breadboard one piece LED six 220Ω resistor six USB Data cable one Schematic File:Lesson23-array.jpg 600px Example program //Define a comdata variable and the initial value is NULL String comdata = ""; //Define a comdata variable and the initial value is NULL //numdata is array to save the character data int numdata[6] = {0}, PWMPin[6] = {3, 5, 6, 9, 10, 11}, mark = 0; void setup() { //Define Pin 0~6 as output for(int i = 0; i < 6; i++) pinMode(PWMPin[i], OUTPUT); Serial.begin(9600); } void loop() { //j is the index in the array numdata int j = 0; //Check the serial buffer, read the string one by one while (Serial.available() > 0) { //Append the string to comdata comdata += char(Serial.read()); //Delay 2ms, serial port will prepare the next number. If not, will lost data delay(2); //Make the serial data, if no data, break this while mark = 1; } if(mark == 1) //If received data, then splite comdata, otherwise no action { //Display input string (optional) Serial.println(comdata); //Display the length of input string (optional) Serial.println(comdata.length()); /*******************Important content*******************/ //Go through the input string by the length for(int i = 0; i < comdata.length() ; i++) { //Analyze the comdate[i], if it is a separator(In this example,it is comma), then analyze next array element //For example:11,22,33,55, the 11 will be stored in numdata[0], when find the comman, j will be increased to 1 //Then will store new character to numdata[1],find the comman again,will use numdata[2],until the end of the string if(comdata[i] == ',') { j++; } else { //If no comma, (input number) * 10 + (the number of read before) //(comdata[i] - '0') means that convert char '0' to ASCII number 0 //If input number is 12345, there are 5 times without comma, then following sentence will execute 5 times //The left number will be got first and numdata[0]=0, //So the first circulation is taht numdata[0] = 0*10+1 = 1 //The second time: numdata[0]=1, circulation is: numdata[0] = 1*10+2 = 12 //The third time: numdata[0]=12, circulation is: numdata[0] = 12*10+3 = 123 //The forth time: numdata[0]=123, circulation is: numdata[0] = 123*10+4 = 1234 //At last the string is 0 numdata[j] = numdata[j] * 10 + (comdata[i] - '0'); } } //comdata string has been converted to number and stored in numdata, clean the comdata for next time using //If not, this time's result will impact next time comdata = String(""); //Output numdata in circle, and write to PWM pin for(int i = 0; i < 6; i++) { Serial.print("Pin "); Serial.print(PWMPin[i]); Serial.print(" = "); Serial.println(numdata[i]); analogWrite(PWMPin[i], numdata[i]); numdata[i] = 0; } //Reset the mark to 0 for next circulation use mark = 0; } 　　　} Result Serial Monitor: In serial window, input six groups data splited by comma, then printed out the PWM value of corresponding six PWM ports File:Lesson23-monitor.jpg 600px LED monitor: In serial window input six groups data splited by common, then you can see the LED's brightness. The higher the value of the digital, the more brightness.