Cheapo logic analyser

[PerranOak]

I’d a logic analyser but don’t want to pay loads for it! 
I guess my best option is a PC based one?
Does anyone have a recommendation for a real tight-wad? (Other than: “put your hand in your pocket you cheap@rse”)
Cheers.

[Fungus]

What bandwidth?

[tggzzz]

You need to think about and tell us:

• what type of signals => threshold voltages
• how many => width
• protection from high voltages, if appropriate
• decoding quantised voltages into digital signals => protocol analysis
• minimum transient you need to capture => sampling rate
• ignoring irrelevant detail => arm/trigger/filter
• stage machine or asynchronous => sampling speed

and anything else so that we aren't playing "20 questions"

[PaulAm]

If you can deal with the limitations you won't get anything cheaper than a Sileae clone.  You can get an 8 bit version for under $10 USD.  They work reasonably well with Sigrok.

More lines, higher bandwidth, etc and the prices go up.

[PerranOak]

Right. You've got me now.

I would use it to decode I2C, UART and such on simple PIC projects (mostly 8-bit, I guess) and maybe the odd USB bit of USB. There will not be any really fast stuff (except USB) so something pretty Micky-Mouse will do.

Cheers.

[CJay]

Cheap as chips Cypress clone of the Saleae with Sigrok has done me proud when I've debugged I2C & slow (ish) SPI.

Sigrok can be a bit flakey, so can the Cypress clone thing but for under a tenner I have absolutely zero grounds to complain, the messing about cost me far less than a 'proper' LA and the combo got me out of a hole on more than a few occasions.

For that sort of money and most of your use case, it's got to be worth a go.

You're going to need to shift some real money to deal with native USB

[Fungus]

something pretty Micky-Mouse will do.

...apart from the "USB" part, which needs several GHz of bandwidth.

[tggzzz]

something pretty Micky-Mouse will do.

...apart from the "USB" part, which needs several GHz of bandwidth.

... raises non-trivial probing problems, and probably needs protocol decoding and packet level decodes.

[DavidAlfa]

Search "24 mhz logic analyzer" in aliexpress/ebay/etc.
For $6 you get 8-ch 24MHz sampling rate, no capture depth limits.
Saleae logic analyzer software is superb, I actually find it better than sigrok, althought it doesn't support so many protocols.

[alm]

Saleae logic analyzer software is superb, I actually find it better than sigrok, althought it doesn't support so many protocols.

No surprise it's better, given that the Saleae software is commercial and only licensed to be used with their hardware. But since they didn't include any copy protection in their first generation of hardware, you'll be able to use their software with the cheap 'clones' as long as you ignore their license until they stop supporting their old hardware.

[DavidAlfa]

I don't use it for working or anything like that. Purely for hobby use,  fiddling around or learning. So the difference for them would be zero.

[PerranOak]

Brill, cheers all.

I think I'll leave the USB element for another time.