good day folks,
im trying to find out how the RC PPM signal stream is like. below is what i have gathered (or not gathered
). i am trying to look into the use of ESC (electronic speed control) for 3phase motor. so im trying to understand what is the signal format like in order to send "artificial" generated PPM to it (without a arduino, just cooking up some pot of logic gates to time it)
1) a frame of data is said to be 20ms, this 1 says its 22.5ms, and that it is maxed at 8channels.
http://www.mftech.de/ppm_en.htm. i saw a frame capture plot from futaba in rcgroups forum, and it is actually 27ms. so in actual, there isnt really a 50Hz standard today am i right? i assume that the limit is up to how the RX is configured to receive streams in its own limits, yes?
2) there are 2 major camps of PPM stream format, a positive mark type, and a spaced type (inverted, futaba style). i am assuming that the norm is actually the positive style that is used in all ESC?
3) some sites denote the header (like a analogue start bit) of each channel is 0.3ms, some say it is 0.7ms. but in actual, it seems the "start" bit have a very wide variance amongst different PPM TX models/brands, so it doesnt matter or does it still have to boil down to a maximum 2ms "bit" width for EVERY gear manufacturer? i assume that if something is more than 3ms, it gets read as a blanking?
4) i have not seen any standard about the blanking width, i assume it has to exceed 1.5 "bit" widths (ie : more than 3ms ?)
thanks for reading, any replies appreciated