Arduino OBD library and software serial library

Question

Can I use Arduino OBD library with "custom" software serial or it needs to be used with hardware UART only? For example if I have D5 and D6 pin as RX and TX in my code hooked on OBD board, how do I initialize OBD library from there?

This is the OBD library that I'm referring to.

And I'm using this Allpro OBD board.

Update Actually I would be satisfied with a answer how to know when entire response from the board is received, because this way is way too messy:

void getResponse(void){
 while(obdSerial.available()){
 Serial.write(obdSerial.read());
 }
}

Here I don't know when the message is received. And if I try to use example from Sparkfun obd-ii-uart-hookup-guide (different board doe) I ended up in infinite-loop since the board never return \r, if I send ELM command to use \n as terminator, and if I disable ELM to echo the command so that I use just one getResponse call I get some readings, but not all the time, I ended up in infinite-loop again.

• Majenko: What / where is an Arduino OBD library? What does its documentation say?
• ShP: Sorry I have updated my question with links.

Answer 1

That library is hard-coded to use the single Hardware Serial device on the Arduino Uno or the second Hardware Serial1 device on other boards.

#ifndef OBDUART
#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168P__)
#define OBDUART Serial
#else
#define OBDUART Serial1
#endif
#endif

You can edit the library's header file OBD.h to define your own serial port though:

#include <SoftwareSerial.h>
extern SoftwareSerial mySerialPort;
#define OBDUART mySerialPort

And then in your sketch create the mySerialPort SoftwareSerial object.

• ShP: I have updated my question again, sorry :) I would really appreciate if you can take another look. But thanks for this one, this is also something that I needed.