LM358 amplifier on a scope

// An LM358 non-inverting amplifier on one 5 V supply, on a scope.
//
// The LM358 is two op-amps in an 8-pin chip. Amplifier 1 is wired as a
// non-inverting amplifier: the signal into 1IN+ (pin 3), 22 k from the output
// (pin 1) back to 1IN- (pin 2), and 10 k from 1IN- to ground. Its gain is
//
//   1 + Rf / Rg  =  1 + 22 k / 10 k  =  3.2
//
// The generator makes a 100 Hz sine from 0.2 V to 1.0 V (0.4 V peak about
// 0.6 V). The scope shows it on channel 1 and the output on channel 2:
// 0.64 V to 3.20 V, the same shape 3.2 times taller and not upside down.
//
// Amplifier 2 is not used. It is wired as a follower of ground (2IN+ to
// ground, 2OUT to 2IN-) so it sits still, which is what you do on a real
// board too.
//
// Things to try:
//   - Turn the generator's amplitude up to 0.6 V and the offset to 0.7 V. The
//     output wants to reach 4.16 V and stops at 3.49 V: an LM358 cannot get
//     closer than 1.5 V to its supply. The bottom still reaches 0.32 V,
//     because an LM358's output goes all the way down to ground.
//   - Change Rf to 47 k: the gain becomes 5.7 and the top clips much sooner.
//   - Open "741 vs LM358 on 5 V" to see why a 741 would not do this job on
//     a 5 V supply.