PPM Pulse Quality

[copterrichie]

Question, is there a way to detect the quality of a PPM stream to the Wii Controller before total failure and the Fail Safe routine kicks in? In other words, will the PPM stream start missing packages etc.

The reason I ask this is, I am curious if this can be used in place of the RSSI signal for FPV.
Thank you.

[mr.rc-cam]

Modern 2.4GHz Rx's do not produce bad servo pulses. Even before a full-out failsafe, it's a common feature to flywheel the servo pulses using the previous (good) values. However, older FM-PPM Rx's will indeed produce corrupted pulses, but quantifying the corruption into a useful RSSI would not be practical. Besides, most old FM-PPM Rx's used FM demodulator IC's that can provide analog RSSI, so no special tricks would typically be needed to obtain RSSI voltage from them.

- Thomas

[copterrichie]

Thank you Thomas, would you happen to know if the HK 6CH Version II has an analog RSSI signal?



http://www.hobbyking.com/hobbyking/stor ... %5FV2.html

[mr.rc-cam]

I don't have any experience with that Rx. But the first thing I would do is measure the voltage on the unused signal pin on the battery input port. Using the voltmeter, observe the voltage on the pin with Tx powered On and then Tx powered Off. If you see a significant difference then you may have been blessed with RSSI. Beyond that, Google around to see if anyone has found RSSI inside the PCB.

- Thomas