Frame errors now and then

[maniades]

Hi there.

I have just tried my AEM AFR serial port, and although I get some results, nistune doesn't seem to like much what the port outputs.

If I try to watch the port with a serial terminal program (realterm, the first free software I could find: http://sourceforge.net/projects/realterm/) I get a nice AFR output. Everything seems ok, except for frame error now and then. Seems like it will work some seconds with no frame errors, and then it will give a bunch of them.

Nistune can measure AFR for short periods of time, but when it reaches 100 frame errors, it automatically disconnects from the AFR.

I have red around that frame errors could be caused because of noise in the circuit. And that a running engine can cause them, but I have tried with the engine on and off, and I get the same result (no obvious improvement).

Anything I can check? I will take a look at another post I have found here, regarding this some tools to duplicate serial ports, and all that, but I liked to ask first, as perhaps this could be a known issue.


Update with some testings:
I realised my laptop has a craddle which has a serial port in it. So, I got this craddle, and got down to the car. Although it seems to work in my terminal program, and it outputs information just fine, and with no apparent errors, when I try to use it in nistune, it doesn't appear in the list of searial ports.

If I retry to find serial devices, it sometimes appear, but the dissapear the next time I try to find them again. Is like if it was appearing and dissapearing constantly.

Also to extend some information, my usb to com adapter (no the craddle, but the first one I tried), is: Ugreen (brand), and then some chinese characters... so I think I should get a better one... Can anyone advise me on one I can buy in amazon for example? comptaible Brands/Models are welcome.

This is the output I get with my adapter:


Some times, it does as shown in the image. Seems like that are the frame errors.

Any advice is welcome. My electric knowledge is very low, so it might be a hardware fault. For example, in my adapter, y just soldered the GND and data pins, but should I also ground the metal casing of the connector? or any other pin?

Thanks a lot.

[maniades]

Seems like a problem with my other adator, as I have bought a new one, based in the FTDI chipset, and operation seems much smoother. I still get some issues, that I hope will not happen when tunning.

So far so good.

[Matt]

Cheap USB-serial adaptors are terrible for this kind of stuff (they are junk). I had one with a romulator a long time ago corrupting the contents on upload/download which made the ECU go limp.

Legit FTDI adaptors will always work fine. Not sure why the internal port was showing/not showing however

[maniades]

As i discovered later, the serial on the craddle of my laptop is just an usb adapter integrated in the craddle, so it might be due to this.

Anyway, if you could pinpoint a specific model that will surely work, it could be nice, so we can buy straight on.

Thanks, Matt. It continue reporting

[Matt]

Anything linked from FTDI website. Aten (Prolific) is another cable I use which works. Most big name ones like Belkin