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RSSI Tech issues.

PostPosted: Sat Jan 21, 2012 1:11 am
by AlanGP
Watching Bruce's new DIY 5.8 Ghz FPV videos may well answer this question in the fullness of time.

I'm a big fan of the FrSky modules and have fitted a number of them, both one way and telemetry, to various transmitters including Futaba FC-16 and FC-18. I use the small FrSky 4 channel receivers in most of my foamies and parkflyers.

I also have one of the slightly older (last year) HK OSV modules with the $17 camera and the HK/Foxtech 200mW 5.8 TX/RX set. The OSV does not support Return to Launch but has an RSSI input which should give me some indication of impending range issues.

Since I am currently building my first FPV based on the above kit this has become a pressing issue. I am going to fit an additional FrSky DF4R Telemetry RX as a signal monitor and use the RSSI pulse train from that.

The generic problem is this - some RSSI RX outputs are an analogue voltage and some are a variable duty cycle pulse train 100% = lots of signal 0% = no signal - or maybe the other way around. The OSD I am using has an analogue RSSI input and I am looking for a circuit to convert pulse trains to analogue voltage.

Grateful for any pointers.

Re: RSSI Tech issues.

PostPosted: Sat Jan 21, 2012 4:12 am
by RCModelReviews
It's a pretty simple task to convert a PWM signal into an analog voltage -- just a resistor/cap low-pass filter will do it but a two stage filter will work even better. We're talking "cents" worth of components and very simple construction. I'll see what I can do.

Re: RSSI Tech issues.

PostPosted: Mon Jun 23, 2014 6:10 pm
by bob195558
Hi Bruce, RCModelReviews,

I am interested in the FrSky Telemetry Rx-RSSI Signal Strengths and/or Readings in the Taranis X9D-B Radio's Transmitter and Receives,
between the Internal and External X series to the D series Systems.

I do not have a large knowledge of the FrSky Transmitter and Receives Telemetry System and also how OpenTX and erSky9x (x9d_rom.bin) firmwares
compare with the Rx-RSSI and Tx-RSSI Signal Readings between the Internal XJT and External XJT and DJT Transmitters.
When flashing the Taranis Radio with erSky9x (x9d_rom.bin firmware through eepSkye eeprom editor) and making up a Telemetry Cable for the
external DJT Transmitter, you will be able to view the Rx-RSSI Telemetry Signal Readings,
See: ... =60#p79037 for how the Telemetry
connections are made see: ... =60#p79427.

Could you do a Video on the different Rx-RSSI Signal Readings between the Internal XJT Transmitter using OpenTX and erSky9x (x9d taranis)
and the external XJT and the DJT Transmitter Modules to each of the X8R, D8R-XP and D8R II Plus receivers?
And why if there is a reason, to why there is a large difference between the Rx-RSSI Signal Readings that are happening?


Re: RSSI Tech issues.

PostPosted: Tue Jun 24, 2014 8:12 am
by BillGriffiths100
The place to ask for information on this type of topic is: