ASCII reading with arduino - serial-port

Question

This is my first post, I know this theme could be very simple or obvious but I can't figure out how to solve it.
I have a capacitance meter from jyetech wiuch claims to have a 8-N-1 serial output, here is the link to the manual. I just want to read the output with my Arduino Uno, can anyone help me? Here is the code I have done, I'm getting some real data but also some strange characters.
#include <stdio.h>
void setup() {
Serial.begin(38400);
Serial.println("OK");
}
char command[1024];
char commandBuffer[128];
int commandBufferSize = 0;
void readCommandBuffer(int bytesToRead) {
int i = 0;
char c = 0;
while (i < 128 && (i < bytesToRead || bytesToRead <= 0)) {
while (!Serial.available())
;
c = Serial.read();
if (c == '\r' || c == '\n') {
break;
}
commandBuffer[i] = c;
i++;
}
commandBufferSize = i;
}
void readCommand() {
command[0] = '\0';
readCommandBuffer(0);
if (strncmp(commandBuffer, "RCV", 3) == 0) {
commandBuffer[commandBufferSize] = '\0';
int expectedSize = atoi(commandBuffer + 4);
if (expectedSize <= 0 || expectedSize > 1024) {
return;
}
Serial.println("RDY");
int bytesRead = 0;
while (bytesRead < expectedSize) {
readCommandBuffer(expectedSize - bytesRead);
memcpy(command + bytesRead, commandBuffer, commandBufferSize);
bytesRead += commandBufferSize;
Serial.print("ACK ");
Serial.println(commandBufferSize);
}
command[bytesRead] = '\0';
} else {
memcpy(command, commandBuffer, commandBufferSize);
command[commandBufferSize] = '\0';
}
}
void loop() {
if (Serial.available()) {
readCommand();
// "command" now contains the full command
Serial.println(command);
}}

Answer 1

You have to use two serial ports, one to talk to the PC (the usual Serial object), and the other to talk to the instrument.
If you have an Arduino UNO, which has only one hardware serial port, you have to use the software serial library. Mega boards have instead 4 hardware serial ports, which are available through the bulit-in objects Serial1, Serial2, etc.
BTW, just noticed a very similar question was asked awhile ago:
Serial Data communication Arduino