array to serial

Question

i want to send an array of int to another arduino by serial.

To garantie a better robust during the transmission, i added < and> with endMarker and startMarker.

The receiver wait until the Hardware Serial is open, and read the data from the Software Serial from the sender.

Code for the sender:

int test[] = {1, 2, 3, 4, 5, 6, 7};
void setup() {
 Serial.begin(9600); // Hardware Serial
}
void loop() {
 for (byte i = 0; i < 7; i++) {
 Serial.write("<");
 Serial.write(test[i]);
 Serial.write(">");
 delay(500);
 }
}

Code for the reader, i edited the code from here: http://forum.arduino.cc/index.php?topic=396450

// Example 3 - Receive with start- and end-markers
include <SoftwareSerial.h>
const byte numChars = 32;
char receivedChars[numChars];
boolean newData = false;
SoftwareSerial mySerial(10, 11); // RX, TX Software Serial
void setup() {
 Serial.begin(9600);
 mySerial.begin(9600);
 Serial.println("<Arduino is ready>");
}
void loop() {
 recvWithStartEndMarkers();
 showNewData();
}
void recvWithStartEndMarkers() {
 static boolean recvInProgress = false;
 static byte ndx = 0;
 char startMarker = '<';
 char endMarker = '>';
 char rc;
 while (Serial.available() > 0 && newData == false) {
 rc = mySerial.read();
 if (recvInProgress == true) {
 if (rc != endMarker) {
 receivedChars[ndx] = rc;
 ndx++;
 if (ndx >= numChars) {
 ndx = numChars - 1;
 }
 }
 else {
 receivedChars[ndx] = '0円'; // terminate the string
 recvInProgress = false;
 ndx = 0;
 newData = true;
 }
 }
 else if (rc == startMarker) {
 recvInProgress = true;
 }
 }
}
void showNewData() {
 if (newData == true) {
 Serial.print("This just in ... ");
 Serial.println(receivedChars);
 newData = false;
 }
}

I don't know if the problem is the serial.write, that send bytes, or i need to use serial.print to send string.

Answer 1

You are attempting to use an 8-bit binary protocol to transmit 16 bit values, and then wrapping it in ASCII characters. There is:

• No way to differentiate the ASCII characters from the 8 bit binary data, and
• No way to fit 16 bits into an 8 bit protocol.

The simplest way is to use Serial.print to make the whole protocol ASCII:

Serial.print("<");
for (byte i = 0; i < 7; i++) {
 Serial.print(test[i]);
 if (i < 6) {
 Serial.print(",");
 }
}
Serial.println(">");

Which would send out:

<1,2,3,4,5,6,7>

• MarkCalaway: Thx Majenko, can i use the example 5 ( forum.arduino.cc/index.php?topic=396450) to read that output with other arduino?
• Majenko: You can use a variation of it, sure.