Did you also learn how to draw schematics from that book?

This is a more conventional way to draw a schematic. "Flow" should be predominantly from left to right and top to bottom.
View attachment 129031
I didn't bother labeling the opamp terminal numbers or give it a component designator because my schematic editor didn't have a part like that and I just drew lines...

I'm sorry, I wasn't aware of the conventions. I used Eagle to draw the schematic. What software do you use to make these?
Thank you pointing this out, I'll learn to draw schematics properly.

 

Yeah, I did it.
Aye, I think it's the negative voltage
Whenever I supply the op amp with anything less than -0.05V, it mysteriously goes crazy, somehow outputting 7V.
I supplied it with -0.04 to 0.64, and it worked correctly.

No. You cannot output 7V from a 3.3V supply unless it is a boost converter style circuit.

 

I'm sorry, I wasn't aware of the conventions.

There are and the fact that you're willing to learn them will be appreciated by anyone trying to read your schematics. When I was getting my degree, drafting was a required course because all schematics and mechanical drawings were hand drawn.

I used Eagle to draw the schematic. What software do you use to make these?

I used an old version of Eagle. I dislike the meaningless color coding it uses, so I print my schematics to get black and white.

 

After you fix the problem with your scope, i.e. get the scope to display voltages correctly, ask yourself, why are you using an opamp to reduce a 0-4V signal to 0-3V?

 

Aye, I think it's the negative voltage
Whenever I supply the op amp with anything less than -0.05V, it mysteriously goes crazy, somehow outputting 7V.
I supplied it with -0.04 to 0.64, and it worked correctly.

You need to keep the input voltage within the range supported by the opamp:



Allowed input voltage range with your supplies is 0.1-1.8V. Operation outside of that range may not be what you expect.

Why are you using an opamp in the first place? You have a voltage divider on the input (of about 0.4) and a gain of about 1.2, giving an overall gain of about 0.45. You could accomplish that with just a voltage divider.

If you needed buffering, you could use an opamp configured as a voltage follower. Assuming slew rate was sufficient.

 

You need to keep the input voltage within the range supported by the opamp:
View attachment 129075
View attachment 129076

Allowed input voltage range with your supplies is 0.1-1.8V. Operation outside of that range may not be what you expect.

Thank you for pointing it out, I didn't notice it! Oh that explains a lot.

No, what I was doing there was just testing the set up. I'm waiting for a 20MHZ oscillator to arrive. It oscillates between 0.4 and 2.4V, and I need to get it to oscillate between about 0.5-0.8V to 2.8-3V. Which still poses a problem, cause I'll be going beyond its range of operation.

 

For the purposes of your experiment you can just increase R3 to get the incoming signal to within the common mode input range of the opamp.