# Building a low-cost oscilloscope and a function generator [closed]

I want to build an oscilloscope and a function generator as a graduation project in my university. Cost should not exceed 125$or 250$ if the project has more additional features. I will display outputs on a computer screen. I want resources to know what I'm going to do. Please give me as many resources and advices as you can. Here are the specifications required:

• Your labour rate must be nearly cents a day. – Andy aka Jan 6 '16 at 11:11
• For what frequency range ? For very low frequencies, less than 100 kHz maybe 1 MHz material cost: no problem. Anything decent like above 10 MHz: the cost of the component(boards) will easily exceed your budget. – Bimpelrekkie Jan 6 '16 at 11:21
• @Andyaka the mentioned cost is for components only. – ammar Jan 6 '16 at 11:22
• @FakeMoustache Sorry I added the required specifications. – ammar Jan 6 '16 at 11:26
• @Andyaka " ... as a graduation project in my university ..." -> labour rate is negative – Russell McMahon Jan 6 '16 at 11:59

Please give me as many resources and advices as you can.

See below

I will display outputs on a computer screen.

Use a sound card to capture waveforms - it won't work with DC signals but will work from 20 Hz to 20 kHz at normal sampling rates. You can also generate waveforms from software by creating wave files that can be outputted from the sound card.

The only hardware extras you will need is a front-end for the scope part that can handle 24Vp-p and a back end for the function generator that turns the line-out signal to 24Vp-p.

You get at least two input channels on a sound card so weight that against it not working at DC.

• There are many software-only PC sound-card solutions such as this one already. If decided to go this route, note that RIFF .WAV data has some significant complexity across devices, so coding skill should address this to ensure compatibility. – rdtsc Jan 6 '16 at 12:00
• @rdtsc did you not see in my answer where I said "The only hardware extras you will need is a front-end for the scope part that can handle 24Vp-p and a back end for the function generator that turns the line-out signal to 24Vp-p." – Andy aka Jan 6 '16 at 12:02
• If you decide to use your sound card as an oscilloscope, then you could actually measure DC with the methods described by Asmyldof (in response to an earlier question by me) electronics.stackexchange.com/a/180135/79572 Recommended reading! – fredrik.hjarner Jan 6 '16 at 12:09