RSSI on futaba receivers.

[Vitamin J]

I was using a Corona rx and the voltage range for RSSI was only from about .8v to 1.5v and it still worked perfectly with the Trace. The Trace has a built-in buffer for the RSSI signal.

[skylark]

Hiya Kieth.... My Rx does not look the same as the one on the RCflighttest page.
Mine is the one in the first picture of this post.

Please mark sure you get a correct RSSI signal,[Power ON] signal should be greater than [Power OFF] signal.

[MrFollies]

Hiya Skylark.

Thanks for jumping in Skylark.

In that case I'll need to build a buffer that alters the RSSI voltage. Currently mine has 0.26v when at close range and 1.2v when the tx is off.
But that does not explain why it does not work when I try it in reverse. It still does not see any voltage with the configuation tool.

The next step for me is to try it another way. I'll test by applying a 5v voltage to the RSSI pin from a onboard uBEC, just to see if the OSD is able to read the voltage correctly. If that works, then I'll build a difference buffer for the OSD using an op-amp.

This should give me 4.74v at full power and about 3.8v when the tx is turned off. I assume this will be acceptable to the OSD?

@kieth: can you confirm what voltages you saw from your 149 receiver?

[skylark]

OSD can accept 0-5V voltage.
But for RC receiver, [Power ON] signal should be greater than [Power OFF] signal,
so I guess you maybe get a wrong signal(maybe wrong pin) from receiver

[MrFollies]

OSD can accept 0-5V voltage.
But for RC receiver, [Power ON] signal should be greater than [Power OFF] signal,
so I guess you maybe get a wrong signal(maybe wrong pin) from receiver

I don't think so, others have reported similar readings with this rx. I'll do some more testing and report back here.

[MrBob6939]

Hi,

Download this manual from ImmersionRC as here is a mod for Futaba FM receivers...

http://www.immersionrc.com/manuals/E...nual.pdf#page4

Hope it helps

Bob

[Keith]

That's a R168 in IRC's manual, it's a little different than the 149s. The problem is there's at least two versions of the 149, and getting RSSI from some of them are sketchy. I know I've seen a post detailing the "other" 149DP that MrFollie's likely has, it was on RCGroups a long time ago. I wasn't able to dig it up though. I do remember it being a little tougher to do, there was a tiny pin on one of the chips that you soldered to.