Add number of expected responses parameter to speed up Arduino <> Car…

… communications
fust · Mar 20, 2018 · 4f3e11b · 4f3e11b
1 parent db7fdf2
commit 4f3e11b
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Showing 2 changed files with 10 additions and 10 deletions.
diff --git a/libraries/OBD/OBD.cpp b/libraries/OBD/OBD.cpp
@@ -63,29 +63,29 @@ byte COBD::sendCommand(const char* cmd, char* buf, byte bufsize, int timeout)
 	return receive(buf, bufsize, timeout);
 }
 
-void COBD::sendQuery(byte pid)
+void COBD::sendQuery(byte pid, byte num_results)
 {
 	char cmd[8];
-	sprintf(cmd, "%02X%02X\r", dataMode, pid);
+	sprintf(cmd, "%02X%02X%01X\r", dataMode, pid, num_results);
 #ifdef DEBUG
 	debugOutput(cmd);
 #endif
 	write(cmd);
 }
 
-bool COBD::readPID(byte pid, int& result)
+bool COBD::readPID(byte pid, int& result, byte num_results)
 {
 	// send a query command
-	sendQuery(pid);
+	sendQuery(pid, num_results);
 	// receive and parse the response
 	return getResult(pid, result);
 }
 
-byte COBD::readPID(const byte pid[], byte count, int result[])
+byte COBD::readPID(const byte pid[], byte count, int result[], byte num_results)
 {
 	byte results = 0; 
 	for (byte n = 0; n < count; n++) {
-		if (readPID(pid[n], result[n])) {
+		if (readPID(pid[n], result[n], num_results)) {
 			results++;
 		}
 	}
@@ -430,7 +430,7 @@ bool COBD::init(OBD_PROTOCOLS protocol)
 	bool success = false;
 	for (byte i = 0; i < 4; i++) {
 		byte pid = i * 0x20;
-		sendQuery(pid);
+		sendQuery(pid, 1);
 		if (receive(buffer, sizeof(buffer), OBD_TIMEOUT_LONG) > 0) {
 			char *p = buffer;
 			while ((p = strstr(p, "41"))) {

diff --git a/libraries/OBD/OBD.h b/libraries/OBD/OBD.h
@@ -130,9 +130,9 @@ class COBD
 	// get connection state
 	virtual OBD_STATES getState() { return m_state; }
 	// read specified OBD-II PID value
-	virtual bool readPID(byte pid, int& result);
+	virtual bool readPID(byte pid, int& result, byte num_results);
 	// read multiple (up to 8) OBD-II PID values, return number of values obtained
-	virtual byte readPID(const byte pid[], byte count, int result[]);
+	virtual byte readPID(const byte pid[], byte count, int result[], byte num_results);
 	// set device into low power mode
 	virtual void enterLowPowerMode();
 	// wake up device from low power mode
@@ -152,7 +152,7 @@ class COBD
 	// read out MEMS data (acc for accelerometer, gyr for gyroscope, temp in 0.1 celcius degree)
 	virtual bool memsRead(int16_t* acc, int16_t* gyr = 0, int16_t* mag = 0, int16_t* temp = 0);
 	// send query for specified PID
-	virtual void sendQuery(byte pid);
+	virtual void sendQuery(byte pid, byte num_results);
 	// retrive and parse the response of specifie PID
 	virtual bool getResult(byte& pid, int& result);
 	// determine if the PID is supported