The chapter "Why the problem exists" lack the very reason about the inverted serial signal origin :) Who are interested - it is because when Futaba invented SBUS protocol more than decade ago, they found that inverted signal make receiver output signal path to destination (FC, servo etc.) less affected to electric noise. For electronics in those days logical zero as high voltage and logical 1 as low voltage made signal path a bit more reliable. Nowadays better electronics and shorter signal paths in smaller drones eliminated need for signal inversion and now RC circuits use direct signals without inversion.
@@thafactortwentyfour6866how?! 😂 He literally goes through stuff step by step or tells you “watch this if you don’t know X”. I have trouble shot 90% of my problems and learned what I know about FPV through JBs videos.
When I started flying fpv 2016 I did watch a lot of his videos but thru my fpv journey I've learned this guy does not keep shit simple he does shit a lot of time that's way more difficult than it really is so after he makes a video I will watch many more to come up with my on decisions on how shit really goes this guy takes the difficult route and trust me shit don't be that difficult he makes shit difficult sometimes
@@thafactor24 Ill give you that sometimes he goes into depth and does deep dives on topics. Like in this video. However, when JB does, he tells you straight away about it, or in any case there are chapters. You dont have to watch the full video that way. Otherwise I am not sure where he does stuff that is way more difficult..
Man this is the first video that anyone (including yours) where this has been explained properly, linking the issue to the F4 chip and not the F4 FC boards. Well done sir in explaining and explaining the double inversion, such an easy concept when explained properly. I never got this concept pre-covid when I flew before and now that I understand it, nothing is left with SBus/FPort as I moved everythig to ELRS ;) However I have loads of F4 boards so this will be a neat trick. Now, if only you know a trick to repurpose an SPI receiver for something useful now that I added ELRS instead that would be smashing for micros ;)
Did you know that you literally, for me anyway, manage to make the hobby more enjoyable and exciting? Your passion for the tech and showcasing it brings an element to the hobby that I find super enjoyable
I have been using the ELRS SBUS output to install an ELRS received on an old NAZA-M v2 system that only supports SBUS. It works like a charm. Thanks JB for the good content.
I had this situation last week, got it sorted with help at intoFPV, and boom, here's your video explaining everything. LOL Yup, you do amazing work. Cheers!
i just have a RM pocket cc2500 protocol with Sbus receiver. i was struggling to understand difference between Sbus and other protocols, whether i can connect my sbus to a non sbus port etc etc. this one video helped me through lot of questions. Thank u so much. Love from India 👍
Perfect Timing ! I have the same problem witch my aio and flyfish atlas 4. O3 and elrs and want to use gps so now I can with s bus ! I will try, thank you!
I use the SBUS output feature from ELRS to fly my Goosky S1. The flight controller on it does not support crossfire protocol but supports Futaba SBUS which is popular in the heli community. Thanks to this feature I can now bring one remote to fly my kwads and helis!
Yes! It basically outputs the same sbus signal like a futaba receiver. Just configure the ELRS as JB shows and wire it up to the sbus port on the FBL.@@chrisbee5481
The latency coming out of the ELRS receiver is the same, since it is the thing generating the signal. The hardware inverter on the FC adds picoseconds of latency -- essentially none.
The inverter will be a very simple device, potentially as simple as a single transistor and resistor, it will not add any noticeable latency only the time it takes for the transistor to switch which is negligible, most likely in the picosecond range.
You can do this directly on many flight controllers too:- Look at the target parameters (there's a link when you go to flash) and you'll see resource INVERTER 1 C00 or similar, go to the CLI and type resource INVERTER 1 none and that'll free up another UART for use (I was using the Diatone Mamba F405 Mk2, and now have Crossfire on UART1 on the SBUS and TX1 pads).
Unfortunately, many FC do not have a switchable inverter. You won't find an INVERTER resource on those FC. But it's a good idea, and definitely deserves to be included in this tutorial, especially for Crossfire users who can't ouptut inverted SBUS as far as I know.
These are my favorite types of videos that you make. Any chance of getting a "JB's Deep Dives for Dorks" Playlist (if there isn't one already) that bundles all your more technical, firmware bending, pin re-mapping videos? Keep up the great work good sir.
I just got into ExpressLRS a few days ago and thought I needed a Matek CRSF to SBUS converter board to use a Hobby Eagle gyro. However, I couldn't find any for sale and found that Matek has apparently quit making them. Now I know why. ExpressLRS and its developers are amazing.
Joshua Bardwell.. you have definitely earned my subscribing to your Patreon :) It ain't much, but I owe it to you for all the FPV help. Maybe someday I could get to meet you in person, too! maybe.. that would be cool! Still need to work on those flips and tricks though :)
the particular situation for me is my OMP M2 rc helicopter witch I want to wire up with a ELRS RX because I want to get rid of my old futaba T8J.I will test in the future with the help of this particular video thank you Josh :)
That's pretty dang handy. I only have a couple F411 AIO boards left & the F411 only have 2 UARTs. I think all of my F405 FCs have at least 3. Maybe some of the older Mamba mk2 F405 FCs only have 2, I don't remember.
Awesome job thank you for doing this topic. There are some bind and fly airplanes that except s-bus and some gyros that offer safe launch wind mitigation. I also have some old fc for whoops that only have a s-bus pad. 😊
I did this and it worked, but the ELRS wouldn't blink while on battery but it would on USD: Watch out when doing this while using the DJI O3, as it will steal the connection from the ELRS and wont allow it to work. To troubleshoot remove the SBUS cable from the VTX and you should be good to go. Keep in mind you cannot do this if using a DJI controller. Thank you Mr Bardwell. Now I can add. a GPS Module!
The CLI setting does not change whether the input is inverted. It changes whether the FC expects to see an inverted signal. The inverter is a physical hardware device that is installed on the FC and usually is not switchable. So for example, what people used to do once upon a time is get a 2nd inverter and install it on the SBUS wire. Now there are two inverters (one on the wire and one on the FC) and the signal coming in is un-inverted. At that point, you need to use the CLI option to tell the FC that the input is not inverted anymore. There are a few FC that have switchable inverters, where the SBUS pad can change from inverted to un-inverted, but they are rare.
This is great (tho seeminly easy to implement that it's kind of late that they thought of this, (considering how fully-featured even the later release candidate builds were), I can finally upgrade those couple whoops I've got kicking around.
Hi @JoshuaBardwell, I have a question. I have QAVS-2 JB Edition and the same Xilo Stax F4 FC. I also have a DJI o3 Unit, GPS, and Express LRS. The situation is when I invert the TX on the Express LRS, some of the telemetry sensors don't work. When I selected the Inverted TX option, I could get only 9 of the telemetry sensors, and I wanted to see GPS Sats and RxBat on my Radio but could not. When I select the CRSF option on the LULA script of my RX (RM Express LRS RP1) the full sensor is working. But, at that time ELRS couldn't talk to my FC as expected. How can I solve this? I mean it has to be Inverted TX, but I want to have full telemetry sensors, not only 9 of them. Is this possible?
What a coincidence… I spent a few hours last weekend opening up my DTS GT200 with F4 omnibus flightcontroller to check if I could wire my ELRS Receiver to it. It won’t be easy.
It's ironic that in an attempt to make it easy to wire up, they actually make it more complicated. Manufacturers (probably the Marketing departments) make this stuff more complicated by labeling the board's output pads with protocol names. If UART pads were simply labeled active-high or active-low, one would know to simply match the signal appropriately. If it doesn't match, invert it. Job done.
Thank you so much for all the info you've put out there, I am new to the hobby and really appreciate it! I purchased the Xilo Stax F4 v2 along with a RadioMaster R81 receiver. I have it wired to the SBUS pad on the F4 along with GRND and 5v. It bound properly to my TX16s BetaFlight is configured as follows: Serial Rx enabled on UART1 "Receiver Mode" set to Serial, "Serial Receiver Provider" set to SBUS Channel Map set to AETR1234 But, I'm not getting any input from the sticks in BF. Any advice? Also, is there a way to test the SBUS output of the receiver?
This is great. I have one drone, it only has SBUS and DSMX inputs (GepRC Cygnet3). Will the DSM trick work with a DSMX? Update: I did it, I got ELRS working on the Cygnet3 FC. ELRS config was SBUS (non-inverted). The board has no additional DSM pin, just another 3.3v pin, not sure if that's it or not. Either way. It works. Thanks
You run into the opposite problem connecting Fr-Sky to an arduino. The reciever has a build in signal invertor. It's only possible if you Connect the receiver to your arduino behind the signal invertor because the S-BUS on Arduino needs an uninverted signal
Ciao sono capitato sul tuo video perché avevo esattamente questo problema! Incredibile! Ho un vecchio flight controller DYS f4 pro che volevo recuperare ma volevo appunto mettere rx lrs e GPS. Pensavo di mettere su rx3 e tx3 il GPS e su tx1 ed sbus la ricevente lrs Ho capito bene? Al tx1 del flight controller dovrò collegare il tx della ricevente lrs e su sbus del flight controller collegare l'rx della ricevente lrs, ho capito bene? A questo punto dovrò scegliere il protocollo invertito? Spero potrai confermarmi! Grazie mille in anticipo! Un saluto dall'Italia😊
Great video Joshua. I am having an conandrum. I ma looking for an receiver to install with Holybro x650 which operates with Pixhawk 6c, with Radio Master TX16S ELRS ground unit. It seems to me that ELRS is only option but what receiver would be best option without too much wiring hussle? Also I do assume plug to utlize on Pixhawk 6c for receiver will be SBAS plug? Thanks for help.
This is great but I have a question on newer firmare that has CRSF Inverted option (not invert TX pin). I'm using Xilo F4 and HappyModel EP1. When I select inverted crsf I loose telemetry from FC but sticks work, if I set to normal crsf I get FC telemetry but loose sticks. I wonder if inverted crfs is inverting both tx and rx (SBUS snd DSM)?
@joshuabardwell I have an old Emax BabyHawk R that uses a Radiomaster R81 sbus receiver. I just bought a Micro Ranger ELRS module and a couple RP1 receivers. I flashed them according to your video and have them bound to my RM Boxer. Do I wire the TX to the signal pad like my original receiver, change the model to SBUS or InvertedSBUS and leave my radio set to CRSF? Or is there something else I need to change on my radio? Hopefully I’m asking the right question.
very good info, how do i invert a crossfire Nano receiver so i can use it on sbus. i have a taker g4 45a AIO,and crossfire uses tx rx 2 on the taker g4, but my rx 2 pad is burnt out so i cant solder my crossfire to it. there is rx4 but instructions say crossfire uses rx tx 2... hope you can help. thankyou.
Hi! Really great video for a very common problem for those who don't get FPV stuff for free. The only burning question I have: I don't have a wifi capable ELRS receiver (I re-used an old frsky r9m reciever). Can I still configure that somehow (e.g. through Betaflight passthrough)? Thanks!
You didn't show the port tab , since that was a subs pad connected to UART 1 then is it configurable in port tab ? Or is UART1 visible in ports tab or not ?
I have your setup wired this way with gps but for some reason I have to start the flight controller with the usb port to a power bank before plug in the battery? Otherwise the elrs receiver doesn’t bind correctly. It’ll say it’s bound but it isn’t.
If I unplug my 3-in-1 cable I can bind too. I tried removing the yellow (sbus) wire from the 3-in-1 cable but that didn’t fix it. Maybe this won’t work with Dji?
@@GearBangerFPVya right now I’m just living with having to jump start it on a external usb battery power bank. Sorta a pain. I played around with trying to put the receiver on different soldering pads no luck.
A pin was bent inside my flight controller causing it to still be connected even though I had pulled the wire. Bent the pin over and all is well in the world again. You can take a small needle and lift up the black plastic clip holding the yellow wire in on both sides of the 3-in-1 cable or just cut it off. That should solve the conflict issue.
I might be wrong but can't you just set "sbus inversion = off" in the betaflight cli to achieve the same thing? However the zohd copilot is one fc that i can think of that accepts sbus and pwm only and there is no way to change it so this would be super useful for that i would presume.
I think the option you're referring to is "serialrx_inverted". That option doesn't make an F4 processor be able to receive an inverted-serial protocol like SBUS or FPORT. That option is used to tell the FC whether the incoming protocl is inverted or not. So in theory, if you had an uninverted-SBUS signal coming from some device, you could use that option to tell the FC, "hey, you're about to get an SBUS signal, but it's not inverted like you think it should be." Frankly, the name of the tlm_inverted and serialrx_inverted options is consuing and a little bit misleading.
Okay, as someone who is new to expresslrs.... I've got several speedybee F4 stacks (a couple of different Version designations). Since the documentation shows that uart6 is available, I should just be able to connect to that uart using crossfire as the protocol and not have to worry about inverting anything?
so i have one question. i have a CLRacing F4S FC and an ELRS receiver. if i invert the ELRS signal and use the sbus pad could i then use the tele pad for telemetry? i am new this stuff so please bare with me.
I don't know the UART breakdown on that FC so I can't say for sure. Both TX and RX need to be the same UART. Also the TELE input is inverted so you'd need both TX and RX on the receiver to be inverted.
in theory, if betaflight developpers wanted to, could they create an inverted protocol (let's call it XSBUS) that can interpret what a frsky receiver is sending to the f405 through a normal UART ? I am not talking about softserial where the f405 has to do extra work and latency is induced.
No, it's not possible. Interpreting the serial signal is built into the hardware of the STM32 chip. By the time betaflight sees it, it's already been interpreted into 1's and 0's.
Ran into a problem when doing this. (I built Josh's 5"build) When powered by battery the reciver light is solid green and doesn't connect to transmitter. Poking around the ELRS site it says it's "primarily caused by pull-down resistor on the RX pad to aid with SBUS line inversion." Anyone have a work around for this?
great idea. I dont have free uart because i want to use GPS so i can find my drone by coordinates from radio. so i will use sbus. which does not transmit telemetry. uh! so i have to record DVR of every single flight. ...
Depending on your FC you can maybe also use soft serial to create an additional UART, it will be limited to 9600 bauds but that can do the job for GPS (not compatible with CRSF/ELRS or HD video systems). But if you have an SBUS pad this is obviously the best thing to do.
The chapter "Why the problem exists" lack the very reason about the inverted serial signal origin :) Who are interested - it is because when Futaba invented SBUS protocol more than decade ago, they found that inverted signal make receiver output signal path to destination (FC, servo etc.) less affected to electric noise. For electronics in those days logical zero as high voltage and logical 1 as low voltage made signal path a bit more reliable. Nowadays better electronics and shorter signal paths in smaller drones eliminated need for signal inversion and now RC circuits use direct signals without inversion.
I enjoy the rants of a live stream, but these are the videos that brought me to your channel. Clear, concise explanations.
100% agree
I totally disagree this guy will confuse the shit out of you
@@thafactortwentyfour6866how?! 😂 He literally goes through stuff step by step or tells you “watch this if you don’t know X”. I have trouble shot 90% of my problems and learned what I know about FPV through JBs videos.
When I started flying fpv 2016 I did watch a lot of his videos but thru my fpv journey I've learned this guy does not keep shit simple he does shit a lot of time that's way more difficult than it really is so after he makes a video I will watch many more to come up with my on decisions on how shit really goes this guy takes the difficult route and trust me shit don't be that difficult he makes shit difficult sometimes
@@thafactor24 Ill give you that sometimes he goes into depth and does deep dives on topics. Like in this video. However, when JB does, he tells you straight away about it, or in any case there are chapters. You dont have to watch the full video that way. Otherwise I am not sure where he does stuff that is way more difficult..
Man this is the first video that anyone (including yours) where this has been explained properly, linking the issue to the F4 chip and not the F4 FC boards. Well done sir in explaining and explaining the double inversion, such an easy concept when explained properly. I never got this concept pre-covid when I flew before and now that I understand it, nothing is left with SBus/FPort as I moved everythig to ELRS ;) However I have loads of F4 boards so this will be a neat trick. Now, if only you know a trick to repurpose an SPI receiver for something useful now that I added ELRS instead that would be smashing for micros ;)
Excited to see Bardwell pumping out content like this again. Keep it up, JB!
Did you know that you literally, for me anyway, manage to make the hobby more enjoyable and exciting?
Your passion for the tech and showcasing it brings an element to the hobby that I find super enjoyable
I have been using the ELRS SBUS output to install an ELRS received on an old NAZA-M v2 system that only supports SBUS. It works like a charm. Thanks JB for the good content.
I had this situation last week, got it sorted with help at intoFPV, and boom, here's your video explaining everything. LOL Yup, you do amazing work. Cheers!
After half a decade in this hobby I learned something new today. Thanks JB!
i just have a RM pocket cc2500 protocol with Sbus receiver. i was struggling to understand difference between Sbus and other protocols, whether i can connect my sbus to a non sbus port etc etc. this one video helped me through lot of questions. Thank u so much. Love from India 👍
Perfect Timing ! I have the same problem witch my aio and flyfish atlas 4. O3 and elrs and want to use gps so now I can with s bus ! I will try, thank you!
You are like the User's Manual for all drone guys!
Not me
And this is why you're the fpvknowitall, great info
I use the SBUS output feature from ELRS to fly my Goosky S1. The flight controller on it does not support crossfire protocol but supports Futaba SBUS which is popular in the heli community. Thanks to this feature I can now bring one remote to fly my kwads and helis!
Will it work on the omp M1 too?
Yes! It basically outputs the same sbus signal like a futaba receiver. Just configure the ELRS as JB shows and wire it up to the sbus port on the FBL.@@chrisbee5481
This video pushed me over the edge to donate and join your Patreon 😀 thank you for all you do in the community!
Awesome! Thank you!
Thank you! I can put black box on my F4 toothpick now!
How delightfully convoluted!
And the double inversion does nothing to exacerbate latency issues?
The latency coming out of the ELRS receiver is the same, since it is the thing generating the signal. The hardware inverter on the FC adds picoseconds of latency -- essentially none.
The inverter will be a very simple device, potentially as simple as a single transistor and resistor, it will not add any noticeable latency only the time it takes for the transistor to switch which is negligible, most likely in the picosecond range.
No, not at all. The latency of the hardware inverter is in the picoseconds range.
Ty JB. I needed this for my emax f4 magnum stack. I learned something new today. Your the man.
Thx, that helped me. Actual INAV version has an invert box in the reciever tab, can be easyly used to use the SBUS as RX1 pin.
I have alot old f411fc's for inav use witch always gps in my case. Since i went digitale i dident use them, but now i can with Elrs, thats fantastic!
My favourite kind of video too!!
And I don’t even use Elrs !
Thanks for all the education Joshua !
Does inverting the signal twice introduce any delay in the signal or is it so fast anyway that it is negligible?
dudeeeee, I almost purchase f7 fc,. big thanks to u,. awsome
Another great video!
Thank you Joshua!!! I didnt know this......Now i can use elrs on my older kwads my eachine wizard 220 X and the babyhawk r 3inch :)
Thanks for this!
Gracias por la majestuosa lección
This was great. Such good content 👍
Joshua for president🎉
The last thing any guvmint wants is someone who will educate their constituants 😂
Thank´s for this information!
Thanks a bunch for all the info, Joshua! 😊
Stay safe there with your family! 🖖😊
This is exactly why I’m a patron of yours.
You can do this directly on many flight controllers too:-
Look at the target parameters (there's a link when you go to flash) and you'll see resource INVERTER 1 C00 or similar, go to the CLI and type resource INVERTER 1 none and that'll free up another UART for use (I was using the Diatone Mamba F405 Mk2, and now have Crossfire on UART1 on the SBUS and TX1 pads).
Unfortunately, many FC do not have a switchable inverter. You won't find an INVERTER resource on those FC. But it's a good idea, and definitely deserves to be included in this tutorial, especially for Crossfire users who can't ouptut inverted SBUS as far as I know.
These are the best videos !
Great info i can use ELRS in a old dji lite, I love it.
These are my favorite types of videos that you make. Any chance of getting a "JB's Deep Dives for Dorks" Playlist (if there isn't one already) that bundles all your more technical, firmware bending, pin re-mapping videos?
Keep up the great work good sir.
This is the one. I have this limitation and thank you JB.
Thank you for mentioning Ardupilot. I have a F405 RadioLink FC that only has 2 telemetry ports and an SBUS input. Yes!
Bravo Bardwell 👍
That is really NICE Joshua! ❤
Dude lol! Great video thanks again! Just bought 2 of your shirts! And saw the patreon after I wrote this. Its coming next
I just got into ExpressLRS a few days ago and thought I needed a Matek CRSF to SBUS converter board to use a Hobby Eagle gyro. However, I couldn't find any for sale and found that Matek has apparently quit making them. Now I know why. ExpressLRS and its developers are amazing.
The HE a3super4 and mini will take crsf now too which is pretty cool.
@@RubyS.1Yeah, I saw that a little while ago.
User defined receiver output protocol! That is brilliant. Open source ftw! 😊
can do it on crossfire since day 1. :)
great content. thanks JB
It's entirely possible this explains the issue I've been having with one of my quads. To the workbench!
Hey man love your videos!
Thank You!
Mamba F405 stack works without inverting the signal on the sbus pad. You can send normal crossfire signal in
really???
Joshua Bardwell.. you have definitely earned my subscribing to your Patreon :) It ain't much, but I owe it to you for all the FPV help. Maybe someday I could get to meet you in person, too! maybe.. that would be cool! Still need to work on those flips and tricks though :)
the particular situation for me is my OMP M2 rc helicopter witch I want to wire up with a ELRS RX because I want to get rid of my old futaba T8J.I will test in the future with the help of this particular video thank you Josh :)
Thats blown my mind !
I’ve been running sbus for years now lol 😅 even on crsf
Brilliant!
Cool! Hope this works on the very earliest ELRS Rx’s from HM.
Well we know what bardwells wifi is called now 🤣.
I think the MSH Brain 2 only uses non inverted sbus and this receiver seems perfect for that!
Ilmu daging abangkuhhh , thanks 🔥🔥
I have on my Mamba F405 connected ELRS Rx on S.Bus ant Tx1 and it works with CRSF protocol without issues. No need to use S.bus output from Rx.
Hai, what receiver u have?
That's pretty dang handy. I only have a couple F411 AIO boards left & the F411 only have 2 UARTs. I think all of my F405 FCs have at least 3. Maybe some of the older Mamba mk2 F405 FCs only have 2, I don't remember.
Interesting. I think sbus has more input delay than tx/rx iirc
The SBUS protocol has more latency than the CRSF protocol, but the SBUS pad has no more delay. The latency of the inverter is picoseconds.
@@JoshuaBardwell ohh ok. Thank you for the clarification Jb!
Awesome job thank you for doing this topic. There are some bind and fly airplanes that except s-bus and some gyros that offer safe launch wind mitigation. I also have some old fc for whoops that only have a s-bus pad. 😊
I did this and it worked, but the ELRS wouldn't blink while on battery but it would on USD: Watch out when doing this while using the DJI O3, as it will steal the connection from the ELRS and wont allow it to work. To troubleshoot remove the SBUS cable from the VTX and you should be good to go. Keep in mind you cannot do this if using a DJI controller. Thank you Mr Bardwell. Now I can add. a GPS Module!
Well thats sick 😮
Jb , you just saved my one old baby hawk 2 drone
Got it all soldered up right. Now having issues which uarts to toggle for hooking up an elrs receiver. Still can’t get stick input
i did this with an rly old quad with f1
Cant you just turn the inversion to desired setting in the cli? And use uart one normally with elrs?
The CLI setting does not change whether the input is inverted. It changes whether the FC expects to see an inverted signal. The inverter is a physical hardware device that is installed on the FC and usually is not switchable. So for example, what people used to do once upon a time is get a 2nd inverter and install it on the SBUS wire. Now there are two inverters (one on the wire and one on the FC) and the signal coming in is un-inverted. At that point, you need to use the CLI option to tell the FC that the input is not inverted anymore.
There are a few FC that have switchable inverters, where the SBUS pad can change from inverted to un-inverted, but they are rare.
What's the difference between using inverted crossfire and just using an SBUS here?
Inverted Crossfire has lower latency.
This is great (tho seeminly easy to implement that it's kind of late that they thought of this, (considering how fully-featured even the later release candidate builds were), I can finally upgrade those couple whoops I've got kicking around.
Hi @JoshuaBardwell, I have a question. I have QAVS-2 JB Edition and the same Xilo Stax F4 FC. I also have a DJI o3 Unit, GPS, and Express LRS. The situation is when I invert the TX on the Express LRS, some of the telemetry sensors don't work. When I selected the Inverted TX option, I could get only 9 of the telemetry sensors, and I wanted to see GPS Sats and RxBat on my Radio but could not. When I select the CRSF option on the LULA script of my RX (RM Express LRS RP1) the full sensor is working. But, at that time ELRS couldn't talk to my FC as expected. How can I solve this? I mean it has to be Inverted TX, but I want to have full telemetry sensors, not only 9 of them. Is this possible?
What a coincidence… I spent a few hours last weekend opening up my DTS GT200 with F4 omnibus flightcontroller to check if I could wire my ELRS Receiver to it. It won’t be easy.
Like ExpressLRS....soon.....CAN-bus for drones, it's the car tech drone controllers need eventually.
It's ironic that in an attempt to make it easy to wire up, they actually make it more complicated. Manufacturers (probably the Marketing departments) make this stuff more complicated by labeling the board's output pads with protocol names. If UART pads were simply labeled active-high or active-low, one would know to simply match the signal appropriately. If it doesn't match, invert it. Job done.
iFlight does it right, IMO, by naming the pad nR1 or whatever, meaning "inverted R1".
Hay y'all just figured out sbus to tx and rssi to rx works to, no more flysky for me elrs all day
There is a 2.4 ghz 2 watt radio signal booster from happy model to make flysky go a half mile . But then what about video
Thank you so much for all the info you've put out there, I am new to the hobby and really appreciate it! I purchased the Xilo Stax F4 v2 along with a RadioMaster R81 receiver. I have it wired to the SBUS pad on the F4 along with GRND and 5v. It bound properly to my TX16s
BetaFlight is configured as follows:
Serial Rx enabled on UART1
"Receiver Mode" set to Serial,
"Serial Receiver Provider" set to SBUS
Channel Map set to AETR1234
But, I'm not getting any input from the sticks in BF. Any advice? Also, is there a way to test the SBUS output of the receiver?
A very good thing in v3.3, this sbus output. Avoid usage of converter elrs/sbus for stabilizer like Eagle A3 super 4.
This is great. I have one drone, it only has SBUS and DSMX inputs (GepRC Cygnet3). Will the DSM trick work with a DSMX?
Update: I did it, I got ELRS working on the Cygnet3 FC. ELRS config was SBUS (non-inverted). The board has no additional DSM pin, just another 3.3v pin, not sure if that's it or not. Either way. It works. Thanks
can you do the same with crossfre? i don't see an option on the XF nano RX manual to use inverted signal. only SBUS an inverted.(SBUS, n.i. SBUS)
You run into the opposite problem connecting Fr-Sky to an arduino. The reciever has a build in signal invertor.
It's only possible if you Connect the receiver to your arduino behind the signal invertor because the S-BUS on Arduino needs an uninverted signal
Gold
Ciao sono capitato sul tuo video perché avevo esattamente questo problema! Incredibile!
Ho un vecchio flight controller DYS f4 pro che volevo recuperare ma volevo appunto mettere rx lrs e GPS.
Pensavo di mettere su rx3 e tx3 il GPS e su tx1 ed sbus la ricevente lrs
Ho capito bene?
Al tx1 del flight controller dovrò collegare il tx della ricevente lrs e su sbus del flight controller collegare l'rx della ricevente lrs, ho capito bene?
A questo punto dovrò scegliere il protocollo invertito?
Spero potrai confermarmi!
Grazie mille in anticipo!
Un saluto dall'Italia😊
Is it possible to throw Drone Camps under the SBUS? 😂
Great video Joshua. I am having an conandrum. I ma looking for an receiver to install with Holybro x650 which operates with Pixhawk 6c, with Radio Master TX16S ELRS ground unit. It seems to me that ELRS is only option but what receiver would be best option without too much wiring hussle? Also I do assume plug to utlize on Pixhawk 6c for receiver will be SBAS plug? Thanks for help.
This is great but I have a question on newer firmare that has CRSF Inverted option (not invert TX pin). I'm using Xilo F4 and HappyModel EP1. When I select inverted crsf I loose telemetry from FC but sticks work, if I set to normal crsf I get FC telemetry but loose sticks. I wonder if inverted crfs is inverting both tx and rx (SBUS snd DSM)?
Hello from Siberia! Good kind of video a lot of things you help to realise.
Is the mount you have with the GPS available for purchase anywhere? Or is there a place I can access the file to print my own?
That mount is for the Flite Test EZ-ID. It's here: www.thingiverse.com/thing:4874074
@joshuabardwell I have an old Emax BabyHawk R that uses a Radiomaster R81 sbus receiver. I just bought a Micro Ranger ELRS module and a couple RP1 receivers. I flashed them according to your video and have them bound to my RM Boxer. Do I wire the TX to the signal pad like my original receiver, change the model to SBUS or InvertedSBUS and leave my radio set to CRSF? Or is there something else I need to change on my radio? Hopefully I’m asking the right question.
very good info, how do i invert a crossfire Nano receiver so i can use it on sbus. i have a taker g4 45a AIO,and crossfire uses tx rx 2 on the taker g4, but my rx 2 pad is burnt out so i cant solder my crossfire to it. there is rx4 but instructions say crossfire uses rx tx 2... hope you can help. thankyou.
Pretty sure CRSF receiver can be set to output SBUS.
@@JoshuaBardwell thankyou joshua, i will look into how to do this. and thanks again.
Hi! Really great video for a very common problem for those who don't get FPV stuff for free. The only burning question I have: I don't have a wifi capable ELRS receiver (I re-used an old frsky r9m reciever). Can I still configure that somehow (e.g. through Betaflight passthrough)? Thanks!
No I don't think so.
You didn't show the port tab , since that was a subs pad connected to UART 1 then is it configurable in port tab ? Or is UART1 visible in ports tab or not ?
You would configure UART 1 as usual for CRSF. The fact that the inverter is present doesn't matter.
I have your setup wired this way with gps but for some reason I have to start the flight controller with the usb port to a power bank before plug in the battery? Otherwise the elrs receiver doesn’t bind correctly. It’ll say it’s bound but it isn’t.
I’m having the same problem. Are you using the DJI 3-in-1 cable connection for your vtx?
Yes
If I unplug my 3-in-1 cable I can bind too. I tried removing the yellow (sbus) wire from the 3-in-1 cable but that didn’t fix it. Maybe this won’t work with Dji?
@@GearBangerFPVya right now I’m just living with having to jump start it on a external usb battery power bank. Sorta a pain. I played around with trying to put the receiver on different soldering pads no luck.
A pin was bent inside my flight controller causing it to still be connected even though I had pulled the wire. Bent the pin over and all is well in the world again.
You can take a small needle and lift up the black plastic clip holding the yellow wire in on both sides of the 3-in-1 cable or just cut it off. That should solve the conflict issue.
I might be wrong but can't you just set "sbus inversion = off" in the betaflight cli to achieve the same thing? However the zohd copilot is one fc that i can think of that accepts sbus and pwm only and there is no way to change it so this would be super useful for that i would presume.
I think the option you're referring to is "serialrx_inverted". That option doesn't make an F4 processor be able to receive an inverted-serial protocol like SBUS or FPORT. That option is used to tell the FC whether the incoming protocl is inverted or not. So in theory, if you had an uninverted-SBUS signal coming from some device, you could use that option to tell the FC, "hey, you're about to get an SBUS signal, but it's not inverted like you think it should be."
Frankly, the name of the tlm_inverted and serialrx_inverted options is consuing and a little bit misleading.
This would help me a lot but I'm using 900MHz Express LRS with FrSky R9mx receivers =( (I don't think it would be possible, right?)
10:05 - somebody needs soldering practice :)
Ok but those aren't my solder joints :-)
Running joke... He's fine
Okay, as someone who is new to expresslrs.... I've got several speedybee F4 stacks (a couple of different Version designations). Since the documentation shows that uart6 is available, I should just be able to connect to that uart using crossfire as the protocol and not have to worry about inverting anything?
Correct.
so i have one question. i have a CLRacing F4S FC and an ELRS receiver. if i invert the ELRS signal and use the sbus pad could i then use the tele pad for telemetry? i am new this stuff so please bare with me.
I don't know the UART breakdown on that FC so I can't say for sure. Both TX and RX need to be the same UART. Also the TELE input is inverted so you'd need both TX and RX on the receiver to be inverted.
@@JoshuaBardwell got it thanks. Love the vids keep up the great work.
in theory, if betaflight developpers wanted to, could they create an inverted protocol (let's call it XSBUS) that can interpret what a frsky receiver is sending to the f405 through a normal UART ?
I am not talking about softserial where the f405 has to do extra work and latency is induced.
No, it's not possible. Interpreting the serial signal is built into the hardware of the STM32 chip. By the time betaflight sees it, it's already been interpreted into 1's and 0's.
Ran into a problem when doing this. (I built Josh's 5"build) When powered by battery the reciver light is solid green and doesn't connect to transmitter.
Poking around the ELRS site it says it's "primarily caused by pull-down resistor on the RX pad to aid with SBUS line inversion."
Anyone have a work around for this?
great idea. I dont have free uart because i want to use GPS so i can find my drone by coordinates from radio. so i will use sbus. which does not transmit telemetry. uh! so i have to record DVR of every single flight. ...
Depending on your FC you can maybe also use soft serial to create an additional UART, it will be limited to 9600 bauds but that can do the job for GPS (not compatible with CRSF/ELRS or HD video systems). But if you have an SBUS pad this is obviously the best thing to do.
@joshuabardwell your shirt is covered in cat dander lmao
Isn't inverted SBUS just IBUS?
Inverted SBUS is SUBS
Not quite, no.