Having an oscilloscope can save lots of time while working on an electronics project, but affording one seems a bit far fetched for a student when the scopes usually cost more than a couple hundred dollars. However there are a few alternatives that a studetn can use without having to spend too much.
Soundcard Scope is a software, free for non-commercial use which uses the soundcard of a computer and shows signals coming in from the soundcard as waves in a scope on the computer screen. The software has many features which make it quite useful and at par with expensive oscilloscopes. It can record a signal, show relevant measurements on screen.
However, the soundcard of computers cannot handle voltages above 0.7V (positive/negative) hence a voltage divider is needed to bring the input voltage level down and to be able to measure higher voltage levels. A 100k oscilloscope probe works best and gives better resolution though additional protection diodes are needed to protect the soundcard of computer.
I will be putting up a circuit diagram for a safe probe to use with this software in a couple of days.