Selecting a logic analyzer

[robdejonge]

In order to debug circuits, I'm looking to buy a logic analyzer. I'm on a budget, but I'd rather not spend the money instead of buying something that isn't capable. I care little for oscilloscope features, and am looking to buy a USB logic analyzer. However, I'm struggling to define the requires sample rate I need to watch out for.

Can anyone suggest and explain why?

[WiFive]

https://sigrok.org/wiki/Supported_hardware

[loboris]

Seleae logic analizers are very good, with excellent software, but very expensive.
If you are on budget, you may buy some Saleae compatible LA, like 25 MHz, 8-channel for ~7 US$ or 100 MHz, 16 channel for ~40 US$.
They work with Saleae software (I don't recommend it as it violates the Saleae license, its up to you), you can also use Sigrok/Pulseview.
The 24 MHz one is extremely cheap and works very good for most use cases.

[bobtidey]

Yes. Pulseview works well for medium speed analysis. As well as the common 8 bit logic hardware available you can also use CY7C68013A dev boards which give 16 bit operation.

See https://www.thingiverse.com/thing:2153437 for a 3d printed enclosure for this.

Note that you will struggle to look at USB signals with these clock ranges. You might want to look at using wireshark to monitor usb traffic.

[jcsbanks]

Would something like this be able to measure the time between two CAN bus frames with resolution better than a microsecond? I presume the 100MHz model could.

I use a Kvaser Leaf Light but its time resolution seems to be quantised to 80us.

The ESP32 is requiring an 8us delay added between successive CAN frame transmissions so an automotive gateway doesn't drop frames. The Kvaser sees them all. Just found empirically.

Would like a better method to analyse and oscilloscopes with CAN are expensive.

[loboris]

In my experience, the 24 MHz LA measures 1 us intervals quite precise.
I'we been using it to analyze SPI transactions at 5 MHz without issues.