Where electronics enthusiasts find answers.
djarmyssg wrote:Ya.. we saw it echoed... but it was an echo from the arduino..... not from the OBDshield.Was it ? I thought the LCD was displaying data from the OBD at that point. I'll have to check that. Your answer would make more sense though.
djarmyssg wrote: It says pin 14 (TX-0) has a 4.7k resistor to 5V.... I issolated that risistor and only get 2.2k... could this be an issue???I don't think so. That is the pullup and if it's 2.2K that means the STN1110 would have to sink ~2 mA instead of ~1 mA to make a logic low. I can't see that making a difference.
#include <SoftwareSerial.h>
SoftwareSerial obd(2,3);
char inChar=0;
char inOBD=0;
char rxIndex=0;
char rxDataPC[20];
char rxDataCar[30];
void setup()
{
obd.begin(9600);
Serial.begin(9600);
}
void loop(){
inChar=0;
while(Serial.available()>0){
if(Serial.available() > 0){
//Start by checking if we've received the end of message character ('\r').
if(Serial.peek() == '\r'){
//Clear the Serial buffer
inChar=Serial.read();
//Put the end of string character on our data string
rxDataPC[rxIndex]='\0';
//Reset the buffer index so that the next character goes back at the beginning of the string.
rxIndex=0;
obd.println(rxDataPC);
inChar=0;
getResponse();
delay(20);
getResponse();
}
//If we didn't get the end of message character, just add the new character to the string.
else{
//Get the new character from the Serial port.
inChar = Serial.read();
//Add the new character to the string, and increment the index variable.
rxDataPC[rxIndex++]=inChar;
}
}
}
}
void getResponse(void){
char obdIn=0;
int i=0;
int start=millis();
//If nothing is currently available do nothing and break after 3 seconds
while(obd.available()==0){if(millis()-start>3000){break;}}
while(obd.available()){
//check to see if end of line/message
if (obd.peek()=='\r'){
obdIn=obd.read();
rxDataCar[i]='\0';
Serial.println(rxDataCar);
i=0;
}
// The prompt is sometimes the only thing recieved so this needs to be taken care of
else if(obd.peek()=='>'){
obdIn=obd.read();
Serial.write(obdIn);
}
// Add next character to string
else{
obdIn=obd.read();
rxDataCar[i++]=obdIn;
}
}
}