i.imgur.com/1PZnK0u.png shows a plot of pack rates WITHOUT and WITH the inverter mode at 115k and 400k baud rates from the TX. THIS DOES NOT show the end-to-end latency gains as outlined in the video, but it does show that pack rate (IMPORTANT) is consistent either way. Ignore the spikes. Those go away if Sync is turned off after arming. BTW - these jitter amounts are the BEST I have ever seen on a RX protocol. They are WAAAYYYY less than any other I have tested. It looks like the least possible is WITH the inverter mod. and continues to run at 115k baud. That of course doesn't help reduce the 1.5ms end-to-end, but that's not important to everyone. Low jitter in general does help you run more FeedForward Boost which can easily make up the 1.5ms end-to-end. Either way, with such low jitter from ExpressLRS, it really opens up the possibilities to push FeedForward Boost in Betaflight much harder!
Nice clear tutorial. Thanks. FYI, there have been numerous reports on the ExLRS discord of the super 8 antenna breaking internally. This is probably the number one cause of new users having range issues. I would recommend using the standard r9 dipole.
Agree, actually it was the reason I changed to ExpressLRS since i thought the range sucked on the R9... First day of ELRS i could fly almost 1km on 50hz but with dropouts and 100dbi+ signal before I found out the shielding (inactive part of antenna) had no connection. Just grab a multimeter and beep inner sma with one of the loops and outer side of sma with opposite side of antenna and check if they are shorted :)
Was thinking of exactly this when just yet i checked my R9M if i had done the mod already. Pretty flimsy lead carrying the "heavy" part of the antenna. Always dangling around and most conductives don't like bending. Thanks for the advice! (And somebody tell someone i don't sell washing machines or finger nail insurances - i'm a solder paste inspection specialist 😉)
Nice job Mark! FYI you need to be careful that the leg of the resistor that bends around the PCB is up nice and tight against the PCB. If it has some "play", you can end up stressing the leg as you slide it back into the case, and ripping the pad off the inverter. Ask me how I know :|
Super excited with 10mW competing against 1W. Big thank you to all involved! Loved to join the club, got some hardware but got stuck in wiring up the R9mm to a Matek405std and getting Ardupilot recognizing the R9... any advice - welcome!
Good video! Now on to the internal fan and power-controlled transistor mod! I just did these a few weeks ago and it was a little challenging given my entry-level skills at component soldering. As another comment mentioned, I ended up soldering flexible wire to the legs of the transistor to make the final connections more...flexible. Maybe a video on the 2W heatsink/fan mod? Thanks for sharing this ELRS content!
Be very careful with bending of the resistor. I did this aleady carfully and the resistor ripped of the leg where it was already soldered. I would recommend to solder the other side first or use hot glue to remove the physical stress from the first solder point.
I wish the baud rate and ADC filter were per model for different modules and FC with Rx filtering vs FC without. Almost need two controllers at this rate.
I lose connection after less than a minute running an unmodded Qx7 on EdgeTX with onebit enabled still on the lower baud rate. Going to give this a shot to see if the higher baud fixes it because I love flying with my x7 as my daily driver but might have to use my t16 if I can’t get it right. Seems like I’m not the only one having this issue as well.
@@uavtech got it working with bench test need to do a full test. Seems like the module was unstable with the radio without this mod. And yes the full telemetry works for me now including betaflight lua with version 1.2.0. 400000 was absolutely necessary for me in this case. Thanks for your help I learn most of my info from you and JB.
"Most" is relative. The X9D pushes 400k baud ONLY. However, I ran 400k baud to my R9 without the R9M inverter mod and it was OK. I'm sure it is better to do the mod with the X9D though and maybe an ExpressLRS dev will correct me on how important it is or not. Here is pack rate with and without mod at 115k and 400k baud rates from my Q X7s. Ignore the big spikes. Those go away when you have Sync turn off on arming. What I'm looking at in this image is the packet jitter on the different settings. All are about the same. Of course end-to-end with the mod and X9D+ will be less with the mod vs. without. Also the LUA thing I mentioned in the video are the benifits: i.imgur.com/Yf9iwKc.png github.com/ExpressLRS/ExpressLRS/wiki/Inverter-Mod-for-R9M-2018
Question, Why do we need ADC filter off? Should we have this off running crossfire as well or just ExpressLRS.. I noticed when I turned off ADC on my QX7 with Crossfire mod done and running Full crossfire TX I was getting jittery throttle values showing in betaflight reciever tab. When I turned ADC filtering back ON the jitters on my throttle stopped.
ADC helps with gimbal jitter, but makes bigger and random steps in the TX commands to the FC. I would fly both. If you cannot notice the difference, i would have off. But if better with it on due to gimbal jitter, then leave.on.
donnt run 400 without this mod. i switched to edgetx, forgot to check baud rate. it works but after 5 to 6 minutes the module would start rebootig randomly, had a failsafe once but most times was able to coe back and land.
Hi Mark , need your help, i am trying to convert my old R9M Lite to elrs. i tried 2 releases from ELRS configurator 2.2. and 2.0.0 via BL , but when flashing to firmware.elrs , writing error message "FE update error , no sync" , can you help or do you have video on R9M lite ELRS ? thanks a lot.
I have a problem, my range is so bad with it. 400 meters and failsafe. A new reciever and antenna are helping nothing ( other reciever placement too). I flasht both new? My lq is most of the time high but the rssidb is so low i have after 300meters -90 at 50 mw ???? Can someone help me
I would hop on the ELRS Discord: discord.com/invite/dS6ReFY But if LQ remains OK, then you may be OK. Also check the Signal-to-Noise. JB just did some good content on this subject: ruclips.net/video/seUi-_HV_O4/видео.html
Hi Thank you for the video ! really! :) ... one question though: Do I have to revert my f.port wiring to a classic one to be able to use the betaflight serial passtrought with the R9mini receivers ?
Following intently. Here's a hint that I'm sure you know. Grab a pot of flux, daub little bits on each side (wire and cap) then load up your iron with a blob of solder. Hold the wire to the cap and touch the blob to the joint. Instant perfect joint with no 'points'. #onehandsoldering
many thanks for this video. I have a qx7 accst, r9m 2018 and have done the mod. I changed the band to 400k and lost telemetry on the radio. When I go back to 115K the telemetry comes back. Is this the way it should be? How can I have telemetry on 400K?
This is great stuff, thanks! Just so I'm clear, is this a pointless mod on my R9 (accst version) I don't do the 'crossfire' hardware mod on my 3 year old QX7?
ExpressLRS works fine at 115200 baud, however, if you want 400000 baud and have a REV4 motherboard in your Q X7, both are required: i.imgur.com/4StD2gu.png
First of all thanks for the great tutorial! How can I find out if I have a REV4 motherboard in my QX7? Just so I'm clear, if I don't have a REV4 motherboard, I just need the mod on my R9 (accst version) to use 400k baud rates?
"have to" is not the best way to put it. If you want to, you can. If not, don't. I covered the advantages (which i don't think are huge just this moment) in the video and in the pinned comment. In my pinned comment, i also shows a graph of how in either case, packet rate consistency remains the same with ExpressLRS. I would guess Jumper has the option of 115200 baud or 400000 baud? IDK, I don't have a jumper.
@@uavtech yes it does have both 115k and 400k baud rate, and it defaults to 400k. I probably wont to this mod cause I dont really see a significant advantage by putting the resistor, but to be honest its because i hate soldering on such small pads lol. Also wezley's comment kinda put me off from doing this mod too
The modification on the first QX7 Mainboards ( X7_MAIN _REV03 ) (2016/09/29) is not necessary. They were able to use 400 kbit..... ;-) Only for the REV04 boards this required.
Pretty interesting mod, Mark! Thanks a lot! 😃 Yeah, I guess I'm going to have to do the same! 😕 Do you think it would be easier if you used some flexible wire instead of only the resistor things? So you could easily put it anywhere and pass the wires where there's more space, I don't know... Or just like this is better? Anyway, stay safe there with your family! 🖖😊
Maybe just a thin copper wire (like from coils or motor windings) would do the job. But it shouldn't be too long because you may get some strange behaviour because of capacitive/inductive coupling. So just solder the pre-bended resistor with one leg and use the tin copper wire for the other side.
![☀ Вся правда о R9M LRS от FrSky, ответы на комментарии + окончательное мнение! [Frsky LRS Podcast]](http://i.ytimg.com/vi/ULqJMAVF9F8/mqdefault.jpg)
i.imgur.com/1PZnK0u.png shows a plot of pack rates WITHOUT and WITH the inverter mode at 115k and 400k baud rates from the TX. THIS DOES NOT show the end-to-end latency gains as outlined in the video, but it does show that pack rate (IMPORTANT) is consistent either way. Ignore the spikes. Those go away if Sync is turned off after arming.
BTW - these jitter amounts are the BEST I have ever seen on a RX protocol. They are WAAAYYYY less than any other I have tested. It looks like the least possible is WITH the inverter mod. and continues to run at 115k baud. That of course doesn't help reduce the 1.5ms end-to-end, but that's not important to everyone. Low jitter in general does help you run more FeedForward Boost which can easily make up the 1.5ms end-to-end. Either way, with such low jitter from ExpressLRS, it really opens up the possibilities to push FeedForward Boost in Betaflight much harder!
soooo you dot need the od? i can fash express lrs and do mod later
Nice clear tutorial. Thanks.
FYI, there have been numerous reports on the ExLRS discord of the super 8 antenna breaking internally. This is probably the number one cause of new users having range issues. I would recommend using the standard r9 dipole.
But im using the super 8 with no issues...
Agree, actually it was the reason I changed to ExpressLRS since i thought the range sucked on the R9... First day of ELRS i could fly almost 1km on 50hz but with dropouts and 100dbi+ signal before I found out the shielding (inactive part of antenna) had no connection.
Just grab a multimeter and beep inner sma with one of the loops and outer side of sma with opposite side of antenna and check if they are shorted :)
For anyone still hesitant of the R9 2018 dipole antenna, it is tuned quite well! No need to swap it, that is if you can live with the size.
Was thinking of exactly this when just yet i checked my R9M if i had done the mod already. Pretty flimsy lead carrying the "heavy" part of the antenna. Always dangling around and most conductives don't like bending. Thanks for the advice! (And somebody tell someone i don't sell washing machines or finger nail insurances - i'm a solder paste inspection specialist 😉)
Nice job Mark!
FYI you need to be careful that the leg of the resistor that bends around the PCB is up nice and tight against the PCB. If it has some "play", you can end up stressing the leg as you slide it back into the case, and ripping the pad off the inverter. Ask me how I know :|
oh boy. growing pains. At least the modules are pretty cheap.
Couldn't we keep the Resistor on one side the board and use small silicone wire Jumper to avoid this?
Super excited with 10mW competing against 1W. Big thank you to all involved! Loved to join the club, got some hardware but got stuck in wiring up the R9mm to a Matek405std and getting Ardupilot recognizing the R9... any advice - welcome!
Good video! Now on to the internal fan and power-controlled transistor mod! I just did these a few weeks ago and it was a little challenging given my entry-level skills at component soldering. As another comment mentioned, I ended up soldering flexible wire to the legs of the transistor to make the final connections more...flexible. Maybe a video on the 2W heatsink/fan mod? Thanks for sharing this ELRS content!
Be very careful with bending of the resistor. I did this aleady carfully and the resistor ripped of the leg where it was already soldered. I would recommend to solder the other side first or use hot glue to remove the physical stress from the first solder point.
Hi, great video :) I have R9M lite TX, accst version. There is a mode like in this tutorial? Thanks :)
You always bring the best information!!!
I wish the baud rate and ADC filter were per model for different modules and FC with Rx filtering vs FC without. Almost need two controllers at this rate.
So glad you dig into this stuff. Great vid!
I lose connection after less than a minute running an unmodded Qx7 on EdgeTX with onebit enabled still on the lower baud rate. Going to give this a shot to see if the higher baud fixes it because I love flying with my x7 as my daily driver but might have to use my t16 if I can’t get it right. Seems like I’m not the only one having this issue as well.
Weird. I have an X7 and ran on 115k or 400k without mode without issue.
Same after mod.
🤔
@@uavtech got it working with bench test need to do a full test. Seems like the module was unstable with the radio without this mod. And yes the full telemetry works for me now including betaflight lua with version 1.2.0. 400000 was absolutely necessary for me in this case. Thanks for your help I learn most of my info from you and JB.
Hi Mark! My R9M Module is the ACCST (not ACCESS) 2019 Version (not 2018). My QX7 is also ACCST. It is not clear if I should do this mod.
Both would accept if you wanted. Just remember, not a must. Only an, if you would like, kind of mod.
Hi Mark, if I have the TBS Crossfire Mod on my QX7, do I still need this mod on my R9M module ACCST to run at 400K baud rate......
Yes you do, read the wiki!
Is a 2K resistor OK?
What is the radio mod spoken about at the end and is it or anything else needed if using the taranis x9d plus se accst
I hink the X9D runs at 400,000 baud. Check ELRS Wiki on github. They have a chart which radios need mods.
@@uavtech okay thanks for the reply I've been watching some videos but haven't heard of a radio mod I'll look into it
I have x9d+ se radio and do I have to do a internal mode as welll??
"Most" is relative. The X9D pushes 400k baud ONLY. However, I ran 400k baud to my R9 without the R9M inverter mod and it was OK. I'm sure it is better to do the mod with the X9D though and maybe an ExpressLRS dev will correct me on how important it is or not.
Here is pack rate with and without mod at 115k and 400k baud rates from my Q X7s. Ignore the big spikes. Those go away when you have Sync turn off on arming. What I'm looking at in this image is the packet jitter on the different settings. All are about the same. Of course end-to-end with the mod and X9D+ will be less with the mod vs. without. Also the LUA thing I mentioned in the video are the benifits: i.imgur.com/Yf9iwKc.png
github.com/ExpressLRS/ExpressLRS/wiki/Inverter-Mod-for-R9M-2018
Hi,can i use smd 0805 resistor
As long as within the OHM range, it should be fine.
Question, Why do we need ADC filter off? Should we have this off running crossfire as well or just ExpressLRS..
I noticed when I turned off ADC on my QX7 with Crossfire mod done and running Full crossfire TX I was getting jittery throttle values showing in betaflight reciever tab. When I turned ADC filtering back ON the jitters on my throttle stopped.
ADC helps with gimbal jitter, but makes bigger and random steps in the TX commands to the FC. I would fly both. If you cannot notice the difference, i would have off. But if better with it on due to gimbal jitter, then leave.on.
@@uavtech Ok. Thank you.
Still have to do the mod now with EdgeTX?
I didn't at the start and it was fine in 115k or 400k baud rate.
donnt run 400 without this mod. i switched to edgetx, forgot to check baud rate.
it works but after 5 to 6 minutes the module would start rebootig randomly, had a failsafe once but most times was able to coe back and land.
Hi Mark , need your help, i am trying to convert my old R9M Lite to elrs. i tried 2 releases from ELRS configurator 2.2. and 2.0.0 via BL , but when flashing to firmware.elrs , writing error message "FE update error , no sync" , can you help or do you have video on R9M lite ELRS ? thanks a lot.
I have a problem, my range is so bad with it. 400 meters and failsafe. A new reciever and antenna are helping nothing ( other reciever placement too). I flasht both new? My lq is most of the time high but the rssidb is so low i have after 300meters -90 at 50 mw ???? Can someone help me
I would hop on the ELRS Discord: discord.com/invite/dS6ReFY
But if LQ remains OK, then you may be OK. Also check the Signal-to-Noise. JB just did some good content on this subject: ruclips.net/video/seUi-_HV_O4/видео.html
Hi Thank you for the video ! really! :) ... one question though: Do I have to revert my f.port wiring to a classic one to be able to use the betaflight serial passtrought with the R9mini receivers ?
No, I don't think so as ELRS uses the RX and TX serial pads on the receiver vs. F.port or SBUS
@@uavtech Thx for the feedback!
Following intently. Here's a hint that I'm sure you know. Grab a pot of flux, daub little bits on each side (wire and cap) then load up your iron with a blob of solder. Hold the wire to the cap and touch the blob to the joint. Instant perfect joint with no 'points'. #onehandsoldering
many thanks for this video. I have a qx7 accst, r9m 2018 and have done the mod. I changed the band to 400k and lost telemetry on the radio. When I go back to 115K the telemetry comes back. Is this the way it should be? How can I have telemetry on 400K?
Ummm... i also have the QX7, 2018 module and didn't have that issue. My best advice is hop.on the ELRS Discord and ask the group.
@@uavtech thnx
I have a question. Does the internal tx16s r9m access mod still have to be done to use the r9m 2019 module as elrs? Or can it be put back to normal?
No.
This is great stuff, thanks! Just so I'm clear, is this a pointless mod on my R9 (accst version) I don't do the 'crossfire' hardware mod on my 3 year old QX7?
correct. Just run 115200 baud in that case. Which, like covered, works fine too.
@@uavtech thanks for the reply. I like to tinker and may want to go xfire at some point so gunna do both!
Hmm can you also solder it to a 3v pad? Some reason I remember seeing a video of a guy doing it like that??
that side of the cap there is 3.3v
@@deltageek7177 ah on the resistor he solder to?
Thanks. Will be doing this
You use 680ohm resistor? Im ask cause im not sure
Yup
I never use LUA script betaflight osd RSSI and LQ is more than enough for me so do I need this
No "need".
Express lrs is moving so fast. Those guys are focused it seems
Agreed. They are professional and don't screw around. They get shit done for sure.
I remember there was a "crossfire mod" for qx7 radios. Is that also needed as well as doing this mod to get it working correctly?
ExpressLRS works fine at 115200 baud, however, if you want 400000 baud and have a REV4 motherboard in your Q X7, both are required: i.imgur.com/4StD2gu.png
First of all thanks for the great tutorial! How can I find out if I have a REV4 motherboard in my QX7? Just so I'm clear, if I don't have a REV4 motherboard, I just need the mod on my R9 (accst version) to use 400k baud rates?
Correct. You would need to open up the radio and look on the board for the rev version.
@@uavtech Thank you for your help. I have a ( X7_MAIN _REV0.6 ) (2018/05/15) motherboard, so I should be fine without a modification. :)
@@uavtech
Hi,
Thanks for your useful videos !!!
Is it possible to do the X7 software mod, or only the X7 hardware mod for 400k baud?
Cheers
Do i have to do this? I use a jumper t12 pro with the accst r9m
"have to" is not the best way to put it. If you want to, you can. If not, don't. I covered the advantages (which i don't think are huge just this moment) in the video and in the pinned comment. In my pinned comment, i also shows a graph of how in either case, packet rate consistency remains the same with ExpressLRS.
I would guess Jumper has the option of 115200 baud or 400000 baud? IDK, I don't have a jumper.
@@uavtech yes it does have both 115k and 400k baud rate, and it defaults to 400k. I probably wont to this mod cause I dont really see a significant advantage by putting the resistor, but to be honest its because i hate soldering on such small pads lol.
Also wezley's comment kinda put me off from doing this mod too
Maybe just set to 115200 baud and let it go.
That's it? Just a resistor?
Yup
The modification on the first QX7 Mainboards ( X7_MAIN _REV03 ) (2016/09/29) is not necessary. They were able to use 400 kbit..... ;-) Only for the REV04 boards this required.
Oh. I have to check my version. I got a QX7s i think, it came with halleffekt gimbals
Lucky me, I have some 1k resistors handy!
Pretty interesting mod, Mark! Thanks a lot! 😃
Yeah, I guess I'm going to have to do the same! 😕
Do you think it would be easier if you used some flexible wire instead of only the resistor things? So you could easily put it anywhere and pass the wires where there's more space, I don't know... Or just like this is better?
Anyway, stay safe there with your family! 🖖😊
good idea.
Maybe just a thin copper wire (like from coils or motor windings) would do the job. But it shouldn't be too long because you may get some strange behaviour because of capacitive/inductive coupling. So just solder the pre-bended resistor with one leg and use the tin copper wire for the other side.
ran into the same issue and cant fix it, could you sorder it back on the PCB ?´im tired of the "FW update Error NoSync"
thanks
My friend just paid me to do his r9 module he said it made a huge difference 😂😅 i didnt do shit😊to his radio
1st one to like this video:)