>>989027
your computer doesn't have the hardware necessary to be used as a decent oscilloscope on its own, but

1: sound card's LINE-IN ADC with perhaps a custom driver; will only work to 41/48khz and require a preamp but it's better than nothing

2: picoscope or similar device

>>989027

don't

buy a tektronix tds 360 for <200 bucks

PicoScope

>>989031
>will only work to 41/48khz
41/48 khz is the sampling rate. The ADC will be worthless for anything greater than half that frequency, and even there it's only marginally useful.

If you futz with the signal, though, perhaps by mixing it with a local oscillator tuned to an adjacent frequency, you could turn a high (even GHz-level) frequency signal into something readable by an ordinary sound card.

>>989027
get the DSI138 and if you want to keep it DIY, get the NOT soldered kit and solder it yourself for less than your lunch money from China Express

The other issue with sound card hardware is that generally the input is AC coupled.

USB scopes on eBay
Xprotolab without the oled (I have 2 of the oled versions)

>>989310
Actually maybe not the latter as the software is iffy.

>>989310
Also there is a Picaxe based scope for £10.

Google Picaxe PCB scope

>>989027
USB scope. Basically a fast A-to-D converter (ADC) with a voltage divider (for the case where the measured signal is more than a few volts) and an amplifier (where the measured signal is less than a volt).

Even the best USB scopes don't compare to a dedicated DSO because a PC simply can't handle the data rate (a reasonable DSO will do 10^8 samples/sec, a good one 10^9); and even at much lower data rates, can't do real-time display.

>>989323
USB 1.0 (which is all you'll get on an 8-bit uC) limits you to <1M samples/sec. The PIC's ADC is well below that, and even with an external ADC it probably can't copy the data from the ADC to USB that fast.

Adding to what >>989579 said;
A modern DSO will in all likelihood have a USB output so you can view and log the data output of the scope on your computer, so there's no real advantage to a USB scope apart from low cost and high portability.

What kind of interesting things can I do with a good scope besides looking at waveforms and seeing what frequency or range something is in?

>>989943
If you don't know what you'd need a scope for, there's no point buying a scope. A scope is a specialised piece of equipment.

It's like asking if there's anything cool you can do with a lathe. These's lots of cool things you can do with a lathe, but the doesn't mean you should go out and buy one before you know what to do with it.

>>989579
PIC usb can do 2.0 and you can set up ping pong buffers and some buffer copy shit to fill the buffers from digital pins independently of the main clock
Even then it probably won't be fast enough

>>989949
Well that's why I was asking about using a computer as one, but apparently that's not useful for... whatever is you would do, so now I want to know even more than before, what all do you do with it?

>>989963

here you go:
https://www.youtube.com/watch?v=5s-zocXvk2I&index=16&list=PLEEF560C574189DCA

if youre looking for one on the cheap&cheerful side, try this, itd be portable too if you used a 9v battery as the power supply:

http://www.ebay.com/itm/291521813263?rmvSB=true

>>991440
thank you very much

Don't see the need to make a new thread when this is related.

I need an at least 4 channel logic probe/analyzer with USB logging. I need it for cheap, and I don't mind having to solder/ place parts. If it's something prebuilt it needs to be user reparable.

>>989027
You never said cheapest, so then there's this.

http://www.keysight.com/en/pc-1881370/PCIe-Digitizers-and-Related-Product?cc=SE&lc=eng

This may be a case of "if you must ask, you can't afford it".