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May 25, 2019, 01:19 AM
FJH
FJH
Registered User
Quote:
Originally Posted by PistiPisti
What do I need and how to connect G-RX6 to detect 1S LiPo battery voltage in a DLG?
What does "Battery voltage detection supported" mean?
The receiver sends connected power telemetry data to your transmitter, no need for special connection. Just let your transmitter detect telemetry sensors.
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May 25, 2019, 01:28 AM
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PistiPisti's Avatar
That is nice, thanks.
May 25, 2019, 02:02 AM
https://hmvc.eu/
Quote:
Originally Posted by PistiPisti
That is nice, thanks.
I would like to add that low voltage detection has significantly improved with these receivers. I discovered this after I received the first G-RX8. This is important for those that like to use a Frsky receiver in a 1S setup which is common for DLG's.

All previous receivers suffered a problem which made voltage measurements non-linear below 3.9V and become useless around 3.6V.

The reason why this happened is because the voltage measurement on those receivers take the operating voltage of 3.3V as its reference. As of around 3.8V and lower this 3.3V starts to drop because they use a linear voltage regulator.
Once that reference voltage drops the measurement becomes increasingly optimistic and at a certain point the reported voltage doesn't even drop anymore although the battery voltage continues to drop.

This doesn't happen on the last generation receivers. I think they create a 1.5V reference voltage in their chip. The decreased power consumption also helps keeping the operating voltage at its 3.3V. The improvement is therefore two-fold. It reports the correct voltage and it is able to keep it exactly 3.3V throughout a 1S discharge.

Because the ADC is merely 8-bit and the range is set to 13.2V it is however still quite course (0.55V steps which only warrants a 1 digit precision). For that reason I have converted a few receivers to use the A2 input for reporting the voltage. I can then use a range of only 4.4V and get a higher precision (2 digit). The latter is not really necessary. It's just something I liked doing.
Last edited by hisroyaldudeness; May 25, 2019 at 02:14 AM.
May 25, 2019, 06:46 AM
Aom
Aom
Registered User
OK, wont i put to much strain on the servo thats Y-ed to the batt/rx?

G-rx8 is out of stock at hobbyking and the decoders are only available in china, i cant wait 2 months...
May be worth the wait but we'll see.

pistipisti:

If its like other frsky receivers, the rx has internal measurment of voltage, so just plug the battery in and on your tx search for new sensors, it will pop up in the menu.
May 25, 2019, 08:07 AM
Sagitta Fanboy
Quote:
Originally Posted by Aom
OK, wont i put to much strain on the servo thats Y-ed to the batt/rx?

G-rx8 is out of stock at hobbyking and the decoders are only available in china, i cant wait 2 months...
May be worth the wait but we'll see.

pistipisti:

If its like other frsky receivers, the rx has internal measurment of voltage, so just plug the battery in and on your tx search for new sensors, it will pop up in the menu.
No strain is added to the servo, but be sure the y can handle the full load from all the servos current draw
May 25, 2019, 09:40 AM
Slope & Thermal
Ray Dunn's Avatar
Deleted as a bad idea.
Last edited by Ray Dunn; May 26, 2019 at 06:56 AM.
May 25, 2019, 10:04 AM
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mpjf01's Avatar
I wouldn't be powering the receiver through any of the white plug connectors if the same source is being used to power servos unless the tracks on the PCB have been tested and proven to carry the current loadings required. I'm not aware of anyone doing these tests but that doesn't mean a lot. My suggestion, if servos are to be powered, is to use a Y connector to the battery, receiver and one servo just to be safe.
May 25, 2019, 11:00 AM
Sagitta Fanboy
Quote:
Originally Posted by Ray Dunn
To use the full servo complement, you can usually route power through the S-Bus (not the smartport, which is low power only). In this case there are two power wires in the white six pin socket. (You can customise the supplied lead)

I think that socket is now ready soldered. It is a pig to solder on, being very small and the solder pins needing the water repellent scraped off them. Also need to consider, which side of the board you place it on.

Hope that helps.

Ray
.
The Sbus and S.Port leads on the G-RX6 share the same pair of power pins which are unsuitable for powering the servos. it's only the 8ch units (and the older X4R-SB and X6R) which can use the Sbus ports to provide power to the servos.
May 25, 2019, 02:21 PM
Adam
xStatiCa's Avatar
Quote:
Originally Posted by hisroyaldudeness
I would like to add that low voltage detection has significantly improved with these receivers. I discovered this after I received the first G-RX8. This is important for those that like to use a Frsky receiver in a 1S setup which is common for DLG's.

All previous receivers suffered a problem which made voltage measurements non-linear below 3.9V and become useless around 3.6V.
---snip---
That is awesome news! Thanks for that info. I always tested my receivers and was very critical of the calibration as I want to trigger low voltage around 3.7v but that is very close to the 3.6 so I always wanted to make sure it was calibrated as precisely as I could around that voltage knowing that it will not register much lower than 3.6v. I will still calibrate them but that is great news that If I set it close to that range, It will detect down lower than 3.6v. Most people probably stop sooner but I like to fly longer . I am converting my DLGs to use the G-RX6 from XR4. I will definitely test this out tonight using a variable voltage supply.
May 25, 2019, 04:45 PM
Aom
Aom
Registered User
Thanks for replies, HK is out of stock of the grx8 but i might wait for it to get back in stock, the plane in question is way above my experience anyways, so wont rush the oncoming plausible crash... Y-cable plan B!
May 26, 2019, 06:54 AM
Slope & Thermal
Ray Dunn's Avatar
Quote:
Originally Posted by mawz
The Sbus and S.Port leads on the G-RX6 share the same pair of power pins which are unsuitable for powering the servos. it's only the 8ch units (and the older X4R-SB and X6R) which can use the Sbus ports to provide power to the servos.
That makes sense and is disturbing, as also affects a common use for Sbus to power servos.
I've now found your earlier discussion on another thread here.

I'll delete my post to avoid future confusion.

Ray
Jun 17, 2019, 06:01 PM
Registered User
Quote:
Originally Posted by cjpace
You may be conflating that with the G-XR8 which has one output that can be either channel 8 or S-Bus. On the G-RX6 however, SBus has dedicated output (via the side connector) separate from the six channel outputs. Putting a jumper on ch5-ch6 during bind will change to the pwm channels to 9ms frame rate (default is 18), but it doesn't effect SBUS, which is always 9ms


The red & green LEDs on the receiver should show you if it's bound our not (green on, red off should be normal if it's bound right and the tx is on)
I have a problem with an AHI glider that is fitted with a G-RX6 Emax digital servos - the buzzing / jittering is horrendous. Is there anyway of over-coming this or minimising it (Sbus, using certain channels ...) ? As things stand I might have to turn off the telemetry which is defeating the whole purpose of this receiver in the first place. Also how do you turn SBUS on with the jumpers - channels 5 and 6 which they tell you to connect are at opposite sides of the receiver not beside each other like a G-XR8. Plus the jumpers only seem to cover 2 pins so what pins do you use - positive and negative or other/ e.g. signal ? |Thanks taggarc
Jun 17, 2019, 06:50 PM
Registered User
landru's Avatar
As cjpace mentioned, on the G-RX6, the SBUS input and output are from the small socket on the side of the receiver. The socket was not installed on units by default until recently (or so I understand). None of mine had it installed.

Since in the G-RX6 the PWM output on channels 1-6 is already high precision, I would guess that there's nothing to be gained by using SBUS. It's a different ball game with the G-RX8, where SBUS mode gives you high precision PWM output on more channels than without.

As cj also mentioned, connecting channel 5 and 6 signal pins on the G-RX6 toggles from FS to HS mode. FS is default. It seems like you may need to use a jumper cable, not the included jumper do-dad. I have no experience with EMAX servos. It seems possible that HS mode might help.

Are your servos located close to the receiver antennas? I've found that distance can be a factor. Mind you, you may not be able to change that much.

https://www.frsky-rc.com/wp-content/...-%20manual.pdf
Jun 17, 2019, 07:57 PM
Adam
xStatiCa's Avatar
What would be nice is to have an option to set the Rx to limit output power for the telemetry signal to limit jitter for some very tight fuses where you can’t really separate things well and you don’t need full range telemetry. Remotely configuring it through the link from the transmitter would be even better.
Jun 17, 2019, 11:28 PM
Registered User
Quote:
Originally Posted by xStatiCa
What would be nice is to have an option to set the Rx to limit output power for the telemetry signal to limit jitter for some very tight fuses where you canít really separate things well and you donít need full range telemetry. Remotely configuring it through the link from the transmitter would be even better.
What would be even nicer is to have the servo manufacturers make the servos immune to interference. That's the real problem.


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