7 Things You Need To Know About ExpressLRS PWM Receivers 

You are also reaching a brand new audience as well that dont know any of this stuff.

There is one thing you didn't mention that might affect some RC plane pilots. You can mix serial and PWM outputs. So if you have a gyro or flight controller that uses SBUS/CRSF/etc, but you still need to control some things via pwm directly, you can! I have a plane that came with a gyro for stabilization and it accepts SBUS. However, the gyro doesn't control all everything (throttle, flaps, landing gear, fpv pan/tilt, etc), which means I needed those to be controlled by the receiver. I went to the receiver's config page and looked through each of the channel mappings and found one that let me change it to SBUS. I can't control which one outputs SBUS, but with the channel remapping, that doesn't really matter. Also, when you enable serial mode it disables 2 channel outputs, even if you use SBUS. So a 6-channel PWM receiver becomes a SBUS receivers (with up to 16 channels) and 4 PWM outputs. Also when using 100Hz or 333Hz Full mode with 16 channels, channel 5 gives full resolution. All other modes give it 2 position resolution. That is also important for some things like gyros that are hard-coded to be controlled by channel 5 and they usually have more than 2 modes (off, stabilized, and angle). So FMS brand planes that come with gyros can still be used with ELRS. I do not know if channel 5 is still used to define "armed" for dynamic power in that mode, though.

Servos usually have the center position at 1500us or 1520us (mostly 1520us / Futaba thing) which limits the update rate to 333Hz maximum. Also, there are fast servos that have the center position at 750us / 760us and those usually can make 560Hz update rate. You can think of it as a sort of Oneshot for servos. This is what the 750us check box is for.

OK Bardwell, you got my Patreon subscription today: I was absolutely raging about having to use the stupid web interface to change any of the receiver settings (as opposed to that *other* RC link that allows you to change everything from their LUA script), and didn't know about the "Other Devices" tab. You win.

It's like you read my mind - my Express LRS transmitter module and receivers arrived today and I was going to research converters this weekend (my Navio2 flight controller for my Ardupilot quad only accepts SBUS or PWM).

There is a more elegant way to set channel 5, use the telemitry so when the rssi gets lower a logical switch arms it. I'm using this with my gliders without issue. Always armed but when it's in a 1m radius from me

Try adding the second rx to your ground vxt module but turn it into a head tracker to make it a portable module to Velcro or hard mount it on and off at will.

As someone who races a lot of RC too this remote is awesome I see it being a way more affordable option that is really great

Josh , I just wanna say thank you for all of the information that you share!

Just a quick tip for anyone having issues with their ELRS PWM RX not wanting to power on, or getting weird responses from CH2: CH2 of the Radiomaster receivers (and some other brands) has UART data spit out on boot. This data blast didn't seem to impact many planes, but it is a recurring issue in the Facebook groups for surface vehicles. It can happen with servos, gyros, and some ESCs. The simple fix is to move your CH2 mix to CH3 instead and swap the plug. If you need all your channels on the RX, test and hope that one of your devices can tolerate the boot thing.

Thanks a bunch for the tutorial and all the info, Joshua! 😊 Stay safe there with your family! 🖖😊

This was a very helpful video, lots of information I didn't know I needed

Haha I'm glad you covered these after I was asking you about them earlier in email will look forward to watching later 😊

I did definitely learn something today. The reason I have been a patron for at least 6 years now. I was actually needing a 6th channel for my TRX4. I have the 3ch receiver that came with the XT12 laying around to add. Problem solved now. THANK YOU 🙏

Another great MT12 video !! I am running two receivers in my SCX10 III. One to control the truck steering, throttle, 2 speed transmission and a dig. The other receiver is on the body to run the FPV gimbal and a drone finder beeper to be used as a horn/alarm. I will be making the change you recommended for AUX 5 so my dynamic power works properly. Thank you!

RemoteID: makes Bardwell play with toy cars. 😂 😢

You've bailed me out of some big-time head scratchers. Thanks for being our Sensei Master 🥋👍

Thanks Joshua!

Thanks

You have very thorough videos about this radio. Thanks to you and about two others, I’ve learned how to set up what I need out of this radio so far. Like your throttle lockout and how to set up the shifting servos in my RGT Challenger. Now only if you can show how to turn on the rc leds from the radio. I have led light switches but they don’t seem to function through the radio. I’m using a DumboRc 10ch rx. I was initially using a DumboRc dff-350 radio but wanted to use this M12 but with the 10ch rx. Thanks in advance.

Dude, I tried to thumbs up this video 3 times. Nailed it with this complete guide.

I got into all this while flying fpv edf jets it is a lot of fun different from quads but alot of fun. I have a second boxer all set up for fixed wing. Use the radiomaster ER series of recivers

Great video 👍 For the enthousiasts out there ... BetaFPV has a 14-channel PWM ELRS RX 😉

Maybe the half pulse widths option has something to do with if you were to run dual receivers in parallel for if one fails?

¡Gracias!

Oooh nice filled in thumbnail text!!

you are a great teacher Mr. Bardwell . have you ever thought about a second channel where you could teach us about IP stuff just this morning I'm looking at upgrading my Wi-Fi router and thinking about going with a UniFi - Ubiquiti setup. but here i am watching ELRS videos

Flaperons have entered the chat!

Great video Joshua, I did not realize I could use multiple ExpressLRS receivers in the same aircraft! I have been wondering why RadioMaster’s largest receiver is 8 channel when some airplanes need 10 or more channels. Now I know. Thank you! Dave Messina

Binding multiple receivers to one radio is not exactly new. While not quite as flexible as ELRS,, about 10 years ago I bound 4 frsky D8R receivers to my taranis. Two to the internal module, two to an external module. Each receiver could be configured to listen to the low (1-8) or high (9-16) channels. That gave me 32 full resolution PWM channels on a single radio. A radio that cost about 1/5 of a futaba radio with 12 channels and a handful of static mixers. People love to hate frsky these days, mostly because of crappy SPI receivers they had no hand in, its easy to forget how they revolutionized the industry once upon a time.

I use ELRS on my sail boats. and had no idea I had to arm ch5 for Dymanic power to work. But I just tested and Dynamic power is working and my Channel 5 is set 1500 us so I just left it....Just walked up the street and TX went up to 500mw which is my max.

do elrs rxs let you take advantage of safe mode and as3x in eflite planes or any brand of plane

I have a armma kraton 6s I wanted to turn in long range. Was going to install crossfire since I already have a tango 2, but you loose the AVC( active vehicle control) system) from the spectrum receiver. I was thinking I can use inav with cross fire and make my own avc or is there a way to make the spectrum receiver go long range ?

I'm looking for a pistol grip transmitter for trucks and I need at least 14 PWM channels for each model. Do you think is it possible to do the same channels extention with 2 receivers (like ELRS version) with any of the communication protocols (also means cheaper receivers) that are in version 4in1?

So question for the end points for steering radio gos to 150% but only controlls the servo to 100% anything after nothing happens and my servo is set for way over 180° and still dont get anything after 100%

Hey Joshua could ir flashlights work for night flying?

Hey man can you help me with my hx115 lr and jumper t lite. Has elrs module and I’ve had it flying but idk what I did and now it will bind, act bound, but not show anything up in betaflight for stick input. I’ve watched tons of videos on it tried lots of stuff and even watched your video about it and still nothing.

Hey this is kind of beside the point but have you seen the hexacopter yet it’s called a hexamovr. If you go to quadmovr and check out his videos he has the prototype and it’s a pretty cool idea. Possible build video like the 8s build

Yesss! 👍

Veey interesting! I'm curious, is it possible to assign one of those reciever pins to output ppm? Looking for pwm on most pins but ppm on one of the rx outputs. Cheers, really enjoying this series.

i fly planes mostly but drones are becoming my new favorite but I have zero clue to what to do. I hope I get it correct. I need some help I have a gps bz250 and I want to install it but I just don't know how.

Edited. Tested. dynamic worked on both my ground vehicles with no arm switch. 🤷🏻‍♂️ elrs 3.3.2 i think what ever latest is Wait, so my elrs been stuck at 25mw cause I didn't do aux1 arm on tank. yet I never failsafe. I have 3w vtx and has gotten really blurry. But elrs 25mw didn't failsafe 😮

Hi JB

Good afternoon Mr Josh, i have a question..maybe off topic but still.. i installed an ER8 RX on my copter , and use the Yaapu script on my RM TX16S mk2, have my 6 flight modes under 2 switches, using MP as GCS..seems to work fine.. i'll take off in 'Stabilize' (MP tel's me the right flight modes..), but my Yaapu tel's me i am in 'ALTCTL' this goes on by every flight mode i choose, when i switch to POSHOLD, Yaapu tel's me i'm in ACRO mode, etc, etc, How can i change this? I've updated all the necessary things on my TX.. but still.. need some help with this.. Regards, Morris

I see the VCI shirt JB!!!!! Planning on reviewing the Dove anytime soon?

Can i use for example the SF 2 pos switch to be an arming switch with a special function of overriding CH3 as well as for the channel 5 Aux 1 just on the radio side to have the channel 5 Aux 1 to be in a high position when armed? Am i right Sir Joahua? Newbie question sir

Mr Bardwell, can you explain to the people why dji controller 2 is not working with betaflight, - there is a multiple subject online , but no success.. Speedy bee V4 + o3 air + dji controller 2+ beta flight 4.5. (10.10.0-RC2) ,Is set on UART 2, serial Rx ON, VTX (MPS +DP) . sbus_baud_fast=on , also in the Google.Looks like FC not communicating with o3. Slowly regred all this self build journey... Problem after problem

So... complicated question - bear with me... I have a traxxas vehicle with their version of stability management. It consists of a gyro on the traxxas receiver feeding data back to the radio via telemetry - which the radio processes and recalculates throttle and steering response curves and limits. Is there any combination of receiver and vehicle-mounted flight controller which would be able to duplicate that functionality? I imagine you'd have to have a fairly high telemetry packet rate but do you think EdgeTX would be able to, say, influence a steering or throttle response curve based on returned gyro/accelerometer data? Would betaflight have any issue feeding that data back while disarmed?

Josh, I have an older quad that has a PWM receiver attached to a Naze 32 Flight controller. Can I use a RadioMaster ER5A V2 2.4GHz 5Ch ELRS PWM Receiver to convert to over to ELRS ? Would it be cheaper to replace the FC and ESC pack? Any Suggestions? Thanks.

How about the betafpv elrs SuperP 14 channel PWM??

Have they solved the issue/limitation where you can only get proportional control on channels 1-4? I tried to set up a plane with a PWM receiver about a year ago and I wanted separate aileron channels but in the end it could not be done and I had to use a Y-cable. It turned out anything past channel 4 was 3 position only.

Thank you Joshua, am I right to say all this is also possible with Tracer?

JB did you make a video on how to set up a 3 position switch for a servo with 3 positions? What if we have two 3 position servos to control, which I do on my Vanquish Phoenix. My rock crawlers all use them for the dig functions. Already a Patreon. 😊

Can you bind a pwm receiver to a radio for fpv aka radio master t16s? Or do you need the surface radio

I am planning to switch to ELRS! Buti dont understand if ExpressLRS pwm rxs can receive the full power telemetry (amp,rpm,voltage) from single escs without a flight controller? Anyone has this setup?

750us or half pulse width mode is a way to increase your PWM frequency beyond the typical 400MHz maximum. Obviously, you need a servo or esc that supports that, and they are not common.

This video gave me deja vu. I swear you re used a few seconds of another video there...... I guess it goes to show how much content I've seen over the years.

A little off subject but has anyone figured out a way to configure betaflight through ELRS wifi ?

Would really like to see Mr. Bardwell flying a winged plane (without goggles) 😊

As inexpensive as ELRs RXes can be... how long till we have standalone ELRS servos that bind up like an RX?

Is there a way to make express LRS work with sanwa SSR mode receivers?

im curious now, if you did your range test with no arming channel enabled, causing it to stay at 25mw?

❤

So I have a question, I using a gyro in my plane and it's using ch5 for gyro rates , I'm using sbus , so when I turn gyro on the arming turns off, how can I get the arming reversed so it matches the gyro switch to on.

Betafpv done similar) But still I cannot find one that supports gps connection. (There is crsf-pwm adaptors with gps support, but no elrs+pwm+gps...

My stepdad gave me a receiver for an RC car that somebody shipped to him on accident.... I found the protocol on my jumper transmitter but I didn't know if it would be worth messing around with.

So I guess you turned channel 5 into Spicoli! Always high all the time / permastoned.

Could you not use this to arm the 03 air unit

Can you bind multiple cars to one model ? My Dx5 I HATE changing models.. mostly because the touch navigations buttons are trash. But I see no reason to have different models for 90% of my cars which do the exact same thing.. 2 cars have Dig and gearboxes and they might be different. Of course I asked this in the first 10 minutes.

at a plane most ppl use arm= killswitch=motor off

There should be an option to turn 2 channels to crsf, or even put 2 more pads or something. Cant be that hard

Its funny there was a lot of hype about ELRS for ground without a lot of consideration of its limitations/foibles

I wish this video came out last year when I was setting up my first elrs pwm receiver. I figured out alot of this after a lot of reading and experamenting. Also you should cover what the fellow is doing in this video. Setting a arm switch ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-zLcB24e8ZEc.html

half pulse width seems a helicopter thing

1st

Prove ELRS can do head tracking without HDzero goggles.

Well crap. Now i have zero excuses not to use ELRS. Well, except that everything I have is crossfire.

Wtf is happening. Bardwell doing cars. 😢

ELRS will be what kills the hobby. Even before the FAA has its chance. Nobody wants that level of open source headache. Not any average consumer that buys an ELRS raido and can't figure out why it won't connect. Then realizes it's easier to build a pc, and put software on it thsn it is to get a transmitter to work with a receiver.