Freematics Forum

Hello everyone of the forum.
Due to the influence of COVID-19, the package finally arrived on May 28.
　My car is a Honda Fit. I loaded an engine RPM sketch for a quick test, but it doesn't respond at all.
I also confirmed it with my wife Suzuki Lapin, but it was unresponsive. Even my friend Toyota Corolla Fielder didn't work.
The blue LED on the adapter comes on, but it disappears in about 30 seconds and then does not respond at all.
There is no mistake in the connection between my Adaputer and Arduino UNO. There is no mistake in the sketch of Arduino.
I don't have any technology or knowledge, but while researching various online information, I found from the information on the forum that the communication protocol of OBD2 is CAN 500kbps/29bit for Honda cars after 2010. Therefore, I found that if the communication protocol specification of the library was usually AUTO, but the description corresponding to my vehicle protocol, that is, CAN 500kbps/29bit, was replaced, it worked. So, I rewrote the corresponding part of the library OBD2UART.h and tried again, but it still does not respond.
I don't know what is wrong. Please help me.
Is this a malfunction (initial defective product)?
Sorry for my poor English.
Thank you in advance.

What's your code like?

Stanley, thank you for your prompt reply.
The sketch I used is rpm_led_uart.ino in the OBD2UART folder.
What I corrected is line 115 of OBD2UART.h,

virtual bool init(OBD_PROTOCOLS protocol = PROTO_AUTO);
virtual bool init (OBD_PROTOCOLS protocol = PROTO_CAN_29B_500K);

It was made.
There is one correction in my other post.
In my friend's car Toyota Corolla Fielder, the obd2 adapter worked normally when PROTOCOL above was set to AUTO. Correct and apologize.

Now, let's return to the main subject.

Even if I correct it to PROTO_CAN_29B_500K, it doesn't respond, so I tried to correct this line brute force.
That is,
virtual bool init(OBD_PROTOCOLS protocol = PROTO_ISO_9141_2);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_CAN_11B_250K);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_KWP2000_5KBPS);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_KWP2000_FAST);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_CAN_11B_500K);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_CAN_29B_500K);
virtual bool init(OBD_PROTOCOLS protocol = PROTO_CAN_29B_250K);

I tried all the descriptions, but the result was NG.

Is it possible that the version of the adapter is Ver.2.1?

There is an operation example in FIT in Ver.1.0. I tried the same with my work car Honda N-VAN, but it didn't work.

By the way, connect to android smartphone with bluetooth With the elm327 adapter made in China, it worked fine in every car.
We look forward to your continued support.

This has nothing to do with firmware version (different from hardware version).
Which year is your car? It is probably using ISO9141-2.