Using Arduino to read and write data to RS232 device

[atharvaaalok]

So moving forward should I disconnect the PC from the ECU, connect the Tx of arduino to the Rx of the MiniBoard and then see if the software shows anything about ECU being connected or not?

[GolamMostafa]

Let us do some simple exercises.
1. Disconnect Arduino from the Mini Board.
2. Connect ECU with PC.
3. Open Arduino IDE with a blank sketch.
4. Check that ECU has been detected by the IDE at a virtual COM Port.
5. Open Serial Monitor ar Bd = 9600.
6. Enter the following command in the InputBox (Fig-1) of the SM.

1,RAC,1

Figure-1:
7. Select No line ending option for Line ending tab.
8. Click on the Send Button.
9. Check that the following msg has appeared on the OutpotBox of SM.

1,RAC,1
1,HS,OK,35000,568,1.32,11,30.1

10. if not getting the expected response, then try changing the Line ending tab to Newline option.

[atharvaaalok]

@GolamMostafa Here are the results.
Before connecting ECU to PC.

After connecting ECU to PC

I sent the command for:

1. No line ending
2. Newline
3. Carriage return
   No reply on Serial Monitor

[GolamMostafa]

But when you execute the engine software, you can communicate with the ECU – correct?

With the Arduino IDE/SM, can you detect the ECU? If yes, then which COM port it is?

I don't see the SM. What you have shown is the IDE. Data coming from ECU will appear on the OutputBox of SM (Fig-1. post #63).

[atharvaaalok]

Yes, I tried that, no reply on serial monitor.
(As I say in my previous post at the end)

Also, in the previous post the 2 images correspond to when the ECU USB cable is not connected and connected respectively. A new tab called COM5 appears but doesn't have a particular name.

[GolamMostafa]

@atharvaaalok

A new tab called COM5 appears but doesn't have a particular name.

Please, go to the Device Manager and check that the device (ECU) is there with the driver installed. I believe that the IDE will be able to communicate with the ECU when the Engine Software can.