Is PPM Analog or Digital?

Our FB Group had a massive argument over this question the other day: is PPM signal analog or digital?

I summarise the arguments on the forum, you can also vote/comment on the topics to support your argument. :)

Here are some other arguments from the users…

Bob R. –  It’s analog. The signal of each channel is determined by the width of that channels pulse. All channels are sent together in a compressed pulse. At least that’s how I understand it. There is some delay depending on the pulse width which I think is about 27ms for 8 channels. Cleanflight based FC’s usually average three pulse before responding so the delay is 27×3. Serial links don’t have this dilemma.

Aeryck V. L. –  it’s analog. if you look at the wave on a scope, it is sinusoidal, its not a sharp 0-1 transition. digital implies the transition from 0 to 1 is instantaneous; a ppm stream shows time (albeit very short).

Greg K. – Wrong, it’s digital. You’re wrong on what defines analog and digital. Its digital. By your definition if you look close enough at any signal its analog. Your definition is wrong. PPM is digital.

I don't look at blog comments very often (maybe once or twice a week), so if you have any questions related to multirotor please post it on this forum You're likely to get a response from me faster on there.