When does queryPid return true?

[Ryccoo]

Looking at the code for queryPid method, the docs states:

ELMduino/src/ELMduino.cpp

Lines 575 to 579 in 5d04161

	Return:
	-------
	* bool - Whether or not the query was submitted successfully
	*/
	bool ELM327::queryPID(const uint8_t &service, const uint16_t &pid, const uint8_t &num_responses)

It seems to return the value of connected

ELMduino/src/ELMduino.cpp

Lines 579 to 585 in 5d04161

	bool ELM327::queryPID(const uint8_t &service, const uint16_t &pid, const uint8_t &num_responses)
	{
	formatQueryArray(service, pid, num_responses);
	sendCommand(query);
	return connected;
	}

Looking into the sendCommand method that is called by queryPid

ELMduino/src/ELMduino.cpp

Line 2138 in 5d04161

void ELM327::sendCommand(const char *cmd)

it sets connected to false

ELMduino/src/ELMduino.cpp

Line 2146 in 5d04161

connected = false;

never setting it back to true.

This looks like queryPid would always return false ?

[PowerBroker2]

There are a couple places where the class can detect a good connection:

In get_response() we have:

ELMduino/src/ELMduino.cpp

Line 2313 in 5d04161

connected = true;

And in initializeELM() we have:

ELMduino/src/ELMduino.cpp

Line 126 in 5d04161

connected = true;

ELMduino/src/ELMduino.cpp

Line 148 in 5d04161

connected = true;

ELMduino/src/ELMduino.cpp

Line 169 in 5d04161

connected = true;

[PowerBroker2]

Looking closer, it seems queryPid() returns before calling get_response(), so it will return false all the time. Let me look into this and see if there's a good work around. I may simply turn queryPid() into a void return function since the determination as to if the ELM327 is connected or not happens during the parsing - not querying. Therefore returning the connected status may be irrelevant here.

[Ryccoo]

Yeah that is the case, the docs threw me off
* bool - Whether or not the query was submitted successfully
and also I was using an example from 4 years ago that someone else made, which was prior to the non-blocking / blocking commands, when queryPid used to have get_response code still in it, meaning it read stuff and also returned proper boolean

[jimwhitelaw]

@Ryccoo I just committed a fix for this inconsistency. As suggested by @PowerBroker2, queryPID() now returns void. The code comments and documentation now reflect this. Thanks for finding the issue.