Why I can only display individual data when using WS2813, not all of it. What am I supposed to do?

@LLL Sorry for the trouble with that. I’m suspecting that the rest of your data is not complying with the bit timings that our Addressable LEDs can properly detect.

Have you tried comparing your recorded data to simulation data generated by our Addressable LED analyzer to see if there are some obvious differences? Instructions for generating analyzer-specific simulation data can be found in the link below.
capture file (in .sal file format)

If that doesn’t help, feel free to share your findings, in addition to sharing your capture file (in .sal file format) which shows the issue and we can review that over here.

I found that with the increase of the sampling rate, the collected data can be more obvious. 16MS/s can allow me to display all the data for some programs, but for some other programs, only a part of the data can be displayed, but 24MS/s can allow me to display other parts that cannot be displayed. However, the sampling rate of 24MS/s can only be sampled for a period of time and an error will be reported, which cannot be sampled continuously like 16MS/s. I also tried to read the error instructions and solutions on the official website, but still did not solve my problem. So now I can only use 16MS/s, not 24MS/s.

@LLL Glad to hear the higher sampling rate helped with the decoding issue. It’s likely that some signal edges were not being recorded properly at the lower sampling rate.

Which specific Saleae Logic model do you own out of the ones pictured below?

In particular, the Original Logic (SALEAE001) and Logic16 (SALEAE009) are the most sensitive to ReadTimeout errors as summarized below.

I use this logic analyzer, I have tried 3-4 computers to connect 24MS/s, and all the connections are about 40S automatic error. I also read the Error Message but it still doesn’t seem to work. I don’t know if there was something wrong with me that caused it.

Session 0.sal (8.4 KB)
I found that it failed after I changed other programs. I think the reason for the addressable address is different from the range set by you, so the detection cannot be achieved.
Session 1.sal (204.9 KB)
I can read all the data
I think it is possible to expand the range of addressable addresses to meet various needs?

@LLL Unfortunately, the device you have pictured is not an official Saleae Logic device, and we are unable to provide support for it.

That’s a generic knock-off product, and I think they are notorious for failing to work reliably at higher sample rates; perhaps you’d consider upgrading to a real one:

… and if you qualify, there are even discounted options:

Trust me, I’ve tried both – and the Logic 8 performs way better than the cheap knock-off device. Also, the new Logic 8 hardware has 8 channels of analog and digital as well as higher sampling rates.

All that being said, the RGB LED Analyzer has a known issue pending about widening the timing tolerances for better ‘real world’ performance of the analyzer.

With the tighter tolerances currently implemented, I think higher-performance logic hardware will be more precise on such timing measurements. Also, I wouldn’t be surprised if some LED pixels have sloppier real world performance and the slow sample rates supported on your generic clone could be compounding the issue.

Some possible options to help resolve your issue include:

  • Buy better RGB LED pixels
    (that perform within the analyzer limits + poor timing capabilities of a low-end clone)
  • Buy a better logic analyzer
    (that can more precisely measure fast timing signals like LED pixel signals)
  • Contribute a patch/fix to the Saleae RGB LED analyzer on GitHub
    (so the analyzer is more forgiving with pixels that have such timing issues)
1 Like

Okay, I’ll try again when I buy a logic 8.