RS-232 serial protocol analyzers

[cerickson]

I am thinking of investing in a serial analyzer (hardware or software) and I am wondering what other people are using. Nothing I find really seems to spin my crank. I am hoping to spend less than $250, if possible. Free would be even better. Would like to avoid programs that have annual license fees or limit the license to a single PC install.

[dkinzer]

I am thinking of investing in a serial analyzer (hardware or software) and I am wondering what other people are using.

I've used the HHD Serial Port Monitor with some success. There are both free and paid versions.

http://freeserialanalyzer.com/

[cerickson]

Can that one be used between two microcontrollers or is it just for communications that are going in and out of a PC?

[dkinzer]

Can that one be used between two microcontrollers [...]?

It monitors input/output to/from a PC serial port. I haven't seen a PC-based monitor that could analyze external communication but I suppose it is possible - you'd need two serial ports, one to monitor one direction and one for the other.

[cerickson]

I don't see where the program can display the data from two ports at once but that brings up an interesting idea.

If I take a microcontroller with at least two hardware UARTS, I can hook two of the UART data-inputs to the bidirectional serial connection under test and then output the two streams to one of the UART outputs to go to the PC. And if I have the microcontroller set bit 8 ON in one of the data streams, I can differentiate the two on the same screen. Basically pick a screen font that duplicates the lower 128 characters in inverse video.

Does that sound feasible or am I chasing a red herring down a rabbit hole in a blind alley?

[twesthoff]

That idea could work if you were only interested in text characters (because the high bit is being used). You would also have to have the speed of the stream going to the PC at least twice the speed of the stream you are monitoring, unless you knew that only one direction of the monitored stream would be used at a time.


On 5/9/2016 10:09 PM, General wrote:

I don't see where the program can display the data from two ports at once but that brings up an interesting idea.

If I take a microcontroller with at least two hardware UARTS, I can hook two of the UART data-inputs to the bidirectional serial connection under test and then output the two streams to one of the UART outputs to go to the PC. And if I have the microcontroller set bit 8 ON in one of the data streams, I can differentiate the two on the same screen. Basically pick a screen font that duplicates the lower 128 characters in inverse video.

Does that sound feasible or am I chasing a red herring down a rabbit hole in a blind alley?

[cerickson]

All good points.

Things to think about.

[dkinzer]

I don't see where the program can display the data from two ports at once but that brings up an interesting idea.

Sorry, I didn't mean to imply that the HHD app was capable of monitoring two external streams. I was just saying that it was conceptually possible.

[FFMan]

I wrote a simple datascope app in VB.net using two serial ports when I was reverse engineering an ecu interface.

so long as you have a reasonable PC, and your speed requirements aren't sky high, this works OK. The multi-threaded nature of the serial port handling means this works better than I had expected.

In the old old days I used a product called Feline, which was an add in card for a dos based PC. I still have a working one but for the ecu project there was a non-standard baud rate used and the scope wouldn't allow it - so I wrote my own.