Dshot: Everything You Need To Know | ESC MOTOR PROTOCOLS - PART TWO

[@michaelwilkes0]

@Joshua Bardwell your analogies are really good. I really liked the shivering hands showing the size of pizza. That is a really clever analogy.

[@JoshuaBardwell]

Glad you like it.

[@ChiragChaudhari]

OMG! I cant believe I spent over an Hour listening to you without blinking, and I cant even see (which I love to see) free style flying videos that are 3-5 min long! You Sir do hell of a job explaining all the complicated stuff, in such a way that Now actually can explain somebody else!

[@aerofilmstudios4840]

Man, your channel is must watch for anybody who wants to get in the hobby! I have pretty good machinery background but no clue in electronics/radio. Thank you for making things simple even for those who knew nothing.

[@trickkfpv2529]

38 minutes full of information regarding DSHOT. Thank you very much Joshua. The slide "No Going Back?" was really insightful. Will spread the info in our racing group. Many thought it is not possible.

[@JoshuaBardwell]

Some even argue that multishot works better without the filtering.

[@halflife82]

TL;DW: DShot 600 > Multishot > DShot 300 > DShot 150 > OneShot 42 > OneShot 125 on MOST people's quads (average to low noise quads). Great video as usual Joshua!

[@williamstewart1269]

Joshua, thanks for explaining a complex subject in a manner that is understandable to someone who didn't attend RPI or similar.

[@DrDisintegrator]

Thanks so much. Joshua you are a really good teacher, and these videos are a terrific resource for our hobby community. Just want to say I've built several FPV race quads over the years, and yesterday I finished my 2nd which uses the Bardwell F4 FC. That manual you wrote is super handy. It really helps you do things in the proper order and the explanations are clear, short and precise. Thanks again!

[@paulgeorge1069]

Really a flight controller with a manual in English not changlish. That's reason enough for me to buy one. When are they gonna figure out exit and enter are 2 completely different words, with nearly opposite meanings. Maybe other manufacturer's will have you write their instruction manuals. Hell let me just beg you too contact them and MAKE THAT HAPPEN!

[@jaybird6909]

I seriously feel smarter after your videos. you explain everything so well. Appreciate the work

[@JoshuaBardwell]

Thanks for watching. Glad it's helpful.

[@LeDribFPV]

super informative as always. Thanks Joshua

[@LeDribFPV]

I wont be rushing to be an early adopter of digital. But yeah, I'm excited for it to become commonplace and will be happy to make the switch when it makes more sense/is easier

[@rajkamals2134]

Thank you so much for explaining everything in detail and iam just getting in to this hobby, i haven't even received my quard frame i ordered. Iam watching everything related to FPV drones and your videos are helping me a loot. I just graduated, iam an electronic engineer but understanding all the work gone in to building FC and ESC and protocols and all in the past years is lot more than i could take in mounts. Once again thank you so much for these detailed videos. I hope to be a developer contributing to this community in the future and I also hope you see my post.

[@LeROYtheLAMA]

You should probably not watch old vids like this if youre new to to the hobby. It advances at such a high rate you could/would mess something up by using tutorials, setups, tips etc over a year old.. even 6 months... Its like going from Windows95 to Windows10 every 6 months

[@pboyfpv7254]

Many thanks Joshua. Your video's rock. Fair, unbiased and some great analogies to help understand

[@wickedneurons]

I always dig the hell out of your "No"s. I didn't notice a big difference with dshot on kiss hardware, but when my friend switched, he said it was a lot more sensitive to his inputs. Some people say it's more responsive at lower throttles. I'm really just glad that the race to click the correct things during calibration for esc's for any of my betaflight stuff is finally over. I always worry about my vtx getting hot during the esc calibration mini-game...

[@KCQuadTronX]

i think i literally wake up to watching you every morning and day now especially lol

[@lifeispancakes]

just watched part 1 and part 2 - excellent videos! Another great contribution to the community, much appreciated - learned a lot. And it says something that these videos are linked on betaflights github Wiki! Cheers

[@chrismichaels5216]

Thank you sir, videos like this are why I'm glad patreon exists.

[@JoshuaBardwell]

Thanks for your support!

[@Reecefpv]

Thank you again lol I just asked around about a few things and iv learned so much from u over the past 3 hours of binge watching lol keep it up and thanks again for explaining so well

[@JaydLawrence]

Fascinating. I can't wait to give it a go. It looks like it will be a lot simpler than using PWM, once it becomes widely adopter. Thanks so much for the video Joshua Bardwell.

[@JaydLawrence]

This and digital video need to catch on in a big way.

[@athief]

Ok. Now I know it's time to upgrade from my OneShot125 LittleBee 20A that I never upgraded whatsoever. It's nice to be explained things exhaustively! 👌🏻

[@ManuPithiviers]

Fantastic explanation.Thanks to you soon I will switch to Dshot without a doubt, I prefer exact values without the need of craftsmanship calibration, that fast values with Parkinson more or less advanced.

[@rzijl68]

Again.... thank you so much for the time and effort you put into this. I'ts just awesome. I definately 'learned someting today' (and yesterday, and the day before that). Can't thank you enough for putting this on YT.

[@blackmennewstyle]

OK so i will keep using multishot for now :) Thank you for your hard job Joshua! I really appreciate the presentation! It made me feel like i was going back to university ;) Enjoy your week

[@JoshuaBardwell]

Thanks! I agree that multishot is still a perfectly viable choice for many pilots.

[@MrPrr0]

Great presentation, now I have the knowledge to decide whether or not use dshot, I learn alot from your videos great work Joshua

[@badmofo350]

Thanks putting this presentation together for us.

[@JoshuaBardwell]

+DrFuNK hope it's educational.

[@badmofo350]

Joshua Bardwell it definitely is. I just built a new 4" quad using blheli S and multishot for the first time. I've noticed when a prop gets only slightly bent and out of balance, I get jello in my video at higher throttle settings. I never had this issue before so I'm wondering if multishot has something to do with it. On all my other quads (oneshot125) I can run with slightly bent props and it's fine. I'm rewatching your BF filters videos now. Motor shafts aren't bent. It's fine with brand new props.

[@JoshuaBardwell]

+DrFuNK easy way to find out if multishot is the cause....

[@badmofo350]

Joshua Bardwell yes I know. I'll let you know what happens.

[@garrykennedy5484]

Well??????

[@HayBeseret]

Thanks, again, for all the info you are giving and the hard work. You should get a protocol called after you name, or at least a quad frame :)

[@ryanhenderson4868]

You're ridiculous Josh! Haha @37 seconds: "If you haven't watched that, go ahead and watch that....aaaaaaaaand, now you're back! Hi, welcome back. Lets talk about DSHOT" - Made me laugh pretty hard here at work.

[@SonicStates]

Joshua, thank you very much for such well thought out and well presented information. An incredibly generous use of your time.

[@somiprakash1347]

Such an elaborative explanation ! Thanks man , really helps a lot for newbies like us.

[@tedhancock68]

Very late to the party here. The rapidly changing technology is making it very difficult to build my first quadcopter. In January I had a NAZE32F1 with old SimonK ESCs to save money. Then I saw BLHelisuite and got some Oneshot125 ESCs which worked OK, but then recalibrated themselves horribly one day. I then saw this video and decided to use some DSHOT600 ESCs I bought by accident. Oh, but F1 boards don't support DSHOT600! So SPRACINGF3 it is. However, the reason for this reply is to say what happens if BG lies to you and tells you the capacitor is removed from the Racerstar RS35A V2 when it's not. At 3S the motors will sputter, glitch and chirp at any speed, but the drone is flyable. At 4S, the copter will flip immediately and violently upon takeoff. Therefore, if you're not sure about your ESC capacitor status, try the quad out with a 3S battery first.

[@gavinvd1]

Thank you Joshua, This solved my problem I had today. I had DMA interrupts on DSHOT and my BF# with newly added LED strip :D

[@unitedelectrician4334]

Thank for both video about motor protocol. I have a better understanding now!!

[@Sgyozo]

I've been wondering about the accuracy/resolution of the signals, so i've done some calculations. (i hope i didn't screw it up, haha) BB10 processor ESC's run at 24MHz, Blheli-S ESC's with BB21 at 50MHz. The accuracy depends on the clock speed. If we want to measure the length of the pulse, we (actually the HW counter on the processor) count the clock between the 2 pulses. At 24MHz clock, it means 24000(pwm-1ms), 3000(oneshot125-125us), 300(multishot-12.5us) pulses, At 50MHz clock 50000, 6250, 625 pulses respectively. So, for example if we use multishot, we can cover the FC's 1000 steps in bigger hops. Also, the FC can provide this multishot info in 900 steps (F3 - 72MHz clock) or 2250 steps (F4 - 180MHz) -> for multishot F4 processor is recommended. In theory, BB10 processor could do dshot 150, 300, or even 600, from the cpu clock viewpoint, i'm not sure about the architecture. (BB10 has less RAM, 1 less timers, etc.) Both are 8 bit, unlike KISS's 32bit, where they also use the DMA trick to receive the signal. Noise can really screw up the value of the PWM like signals, for example, if the fc sends 500 constantly, sometimes the noise can trigger the counter at 100, or 300, or whatever. But if the ESC gets only one very different value between close values, it will ignore the way off value. As multishot sends them very often, some ignored values have no effect on performance.

[@airexfpv1596]

Thanks Josh for the protocol explanations... very helpful!

[@JoelDoyle]

You had me at butter smooth locked-in ball ripping on rails...

[@rscofieldfly]

Awesome stuff Joshua, thanks for doing this 2 part video.

[@sollysdronemedia8079]

Great video. Very easy to understand. Thank you

[@AlanColon1979]

Just watched both videos, i'm fairly new to the hobby (4 months or so? more or less) and this explains why going to multishot from the default of OneShot125 helped so much (the difference was huge for me) and why dshot300 seemed to make things a little bit worse (ever so slightly) but the advantage of turtle mode was worth it. My new ESCs can do dshot600 so i'm pretty happy with the way it's handling now :P

[@michaelbrewer7259]

Great video as always! Thanks for the explanation.

[@STEDDiEFPV]

I miss these videos. I wish I could unlearn Dshot so I could watch this again and learn something today

[@blooskyy7]

Thanks Joshua, brilliantly explained

[@subtilo3322]

Very well put together presentation

[@ryanehrlich5705]

I'm running Dshot 600 on my Gemfan Maverick escs which are 32 bit just like the kiss escs. They didn't need any capacitors removed. I did in fact notice a difference in flight characteristics. Rolls especially felt a lot smoother to me. also it eliminated my hubosd cutting out on punchouts due to noise in the system. it's pretty much a no Brainer

[@andreaswinkelbauer1368]

Thanks for this great video! I've got a couple of questions: * what is format of the protocol messages sent by the FC? is there an exact spec document? * how are the throttle values encoded and what is the resolution of the digital throttle values? * would it make sense to only transmit the difference to the previous throttle value instead of the full value (in the extreme case using, e.g., delta-sigma modulation)? Of course, in this case a solution to avoid error propagation would have to be implemented (in case transmission errors are indeed an issue). * do the current ESCs contain some kind of "blackbox" memory to facilitate the analysis/debugging of possible transmission errors? * I understand that reducing delay may further improve performance. Would it thus make sense to update the motor values as the individual bits are arriving at the ESC (of course, this makes sense only assuming that the most significant bits are transmitted over the wire first)? E.g., a new value could be set based on the two most significant bits only, the value then being gradually refined as the bits of lower significance are coming in. In this way, the delay, particularly for large throttle value changes, is further reduced.

[@JoshuaBardwell]

Protocol definition is here, at least in part. blck.mn/2016/11/dshot-the-new-kid-on-the-block/ Throttle values are encoded as an 11 bit value with a 4 bit CRC and one bit used to indicate that the ESC should transmit telemetry (over a separate signal wire, per KISS). Throttle values 1 through 47 are reserved for future use, so there are exactly 2000 steps of resolution available. Differential transmission would allow higher resolution or faster updates with the same baud rate, however given that corruption is inherent in this system, I don't know if it would be a good idea. You would have to do some kind of key-frame technique where the absolute value is transmitted every so many frames, with differential frames in between. But as soon as one frame is lost, there will be a constant offset that won't get resolved until the next key-frame. I think this could play havoc with the PID controller. ESCs have memory but do not have an easy way to communicate back to the FC. The exception is KISS ESCs which are set up to send telemetry to the FC. In fact, there has been a test version of the KISS code that sent error statistics over telemetry. You might could do what you're talking about with updating the ESC value on a bit-wise basis, but I don't think you can check the CRC until all bits are received. So if you got to the final bit and then the CRC was wrong, you would have output incorrect values, negating one of the main advantages of DSHOT, error correction.

[@alwishy2696]

Great explanation Josh

[@tabdougherty8549]

This explains why a budget F3 board i have a couple of, would only run 3 motors when using D-SHOT. I believe i even had to re flash in order for it to function correctly again.

[@JoshuaBardwell]

Yes. DMA conflict.

[@MennoBrox]

I recently ordered RacerStar 30A V2 Esc's from banggood and they came DShot600 ready, capacitor was allready removed.

[@_theoldgamer_]

Great information, as usual. Thanks for the hard work

[@Dobemandan]

Great video as always!! Thank you!!

[@michaelkoster2869]

Thanks Joshua! another great video.

[@MANTA_FPV]

Thanks for these two videos, i definetly learned something today 😊👍🏻

[@captains8077]

Great video, you where un fire 🔥 with the pizza joke, very funny and I did learn a lot ! Thank you

[@Feldwaldwiese]

20:13 that’s why professionals use two soldering irons.

[@peterkjellstrom3100]

Some fairly significant blheli-S info. 1) normal official latest (16.5) has dshot. no need for special version or hex download. 2) The manual recommends bb2(48/50mhz) to run 300 and bb1(24mhz) to run 150.

[@JoshuaBardwell]

+Peter Kjellström who is recommended to run 600 then?

[@peterkjellstrom3100]

Joshua Bardwell kiss24 users? But wrt blheli-S, it's not like Steffen says 600 won't work on bb2 or eat your kitten...

[@youngpadawan7910]

Sick presentation! You the best man :D

[@doktordrone]

thank you, JB 🙏

[@surfmaxinbama]

I LEARNED SOMETHING TODAY!

[@johnnyvermont2122]

good morning....your the man.

[@alexdij4025]

So I saw in the RCgroups Dshot forum you responded to some of the guys not using ground saying that was a bad idea (And I agreed with you strongly) But I was thinking about it and about what they were saying. They suggested that having the ESC grounded by the Signal wire could cause ground loops to occur and in their testing they had less interference in the video system and on the OSD. Not sure if my understanding of ground loops is incorrect but as far as I can tell it occurs when a device has multiple paths to ground causing a loop through the device that can pick up noise. Now what if the ESC is already grounded without the Signal wire? I did some testing with my multimeter and found that the Signal ground was the same as the power ground. Since the power ground was obviously connected to the PDB ground and in my case the PDB ground was connected to the FC ( FC Has a built in Vreg so it gets VCC voltage) and the FC Vbatt ground is the same as the Signal ground on the ESC outputs then in theory the ESCs should be grounded right? I am not a weight freak and don't care if I have to solder 4 more little wires but if it results in less noise in the video system....

[@alexdij4025]

Also if you could do a quick video on ground loops I would be interested, most of the info out there is related to AC and audio systems with 50/60hz hum (Due to AC) However in our case with DC the noise wouldn't come from AC cycling but rather ESC noise. Love your videos and if I wasn't 15 and if I had a job I would donate so the best I can do is thank you. :(

[@JoshuaBardwell]

+Alex DiJ your multimeter is testing with DC. With high frequency AC signals, such as noise transients, signal ground and power ground are not equivalent. There will be voltage difference between the FC ground reference and the ESC power ground reference. Running signal ground keeps the FC and the ESC signal ground reference as close as possible. I wish there were a better way of getting stats on corrupted frames so we could measure these effects objectively.

[@JoshuaBardwell]

+Alex DiJ thanks are very welcome!

[@alexdij4025]

Hmm interesting. So just to be clear using the ESC ground does not cause ground loops/noise in the video system?

[@alexdij4025]

Also are ground loops even a valid problem in our equipment? For instance if I have a VTX with 2 grounds (Input and Output that is intended to go to the camera) Would running both to the OSD cause a ground loop?

[@carlosfpv]

Excellent job.

[@simonbe]

I think there is an additional new problem with dshot which might cause lost frames on a regular frequency: As you explained, the clocks are not in sync. Generally it could be possible to calibrate the esc clock on the pulse of the Digital Signal. However, I don't think this is possible, because the Digital Signal is on an analog Input. Even worse: The Digital Signal might run through an a/d converter...

[@JoshuaBardwell]

There is no need to have a synced clock if the digital protocol is designed correctly. The ESC measures the length of the pulses and derives the clock from them. Perhaps there is some discrepancy that would be so large as to cause the signal to be corrupted, but in general, the lack of a synchronized clock should not be a problem.

[@simonbe]

Joshua Bardwell I thought, as this Input is usually used to have a Signal that uses analog Timing this Input could not be used as clock-Input. Also I wouldn't expect an async Input buffer because it cannot be applied to the analog Signal.

[@philipdezso2930]

Joshua, could make a topic about the discussions that are hot again about using or not using the ESC groundwire to the FC. Causing many issues for PDB/OSD users and with the added protocol of Dshot what is now currently adviced. Thanks. Keep the topics coming. Philip

[@JoshuaBardwell]

Use the ground wire in my opinion.

[@SKIDOOSH]

Xracer v 3.1 and ztw flash esc's ( both 30a and 20a) on 2 of my quads running Dshot 600 flawlessly without any modification...Do they fly better? Can't really tell, but given digial is coming I wanted to get my feet wet..still running multi-shot on my race quad and its still awesome. Quick respone and silky smooth...

[@mlentsch]

Why did I just buy some old blheli multishot ones?? Because I'm impulsive... and addictive... and impatient...

[@MrSabram07]

So if I'm working with an older drone with a older individual ESC am I better off simply going with One shot just to be safe. You know assume that this ESC will not support Dshot so using Oneshot as a coverall, it's still works good enough.

[@Cornflakes691]

the racerstar escs now have the capacitor removed. I am running 30 amp v2 dshot 600 no nods

[@keithgilbert835]

Joshua you are an Awesome resource. I really appreciate your critical thinking and attention to detail in your posts. I am currently running the Brainfpv with Multi-shot and it works great. I may give Dshot a try or wait as you suggest for the evolution to continue? Thanks

[@JoshuaBardwell]

+Keith Gilbert have it a try if you want...

[@MrStevegibb]

My only concern is that with dshot on blheli_s esc's is that the processor doesn't natively support dma digital signals and quite a bit of the processing power is being used to drive the interupt driven dma signal reading. I worry that even using BB2 esc's running high rates 8khz plus on high kv setups could overload the bb2 processor perhaps causing it to loose sync or just restict output power. This is something the kiss 24 esc's dont have a problem with as the dma dshot signal is natively supported by the 32bit processor so running dshot will not add any extra load to the cpu.

[@JoshuaBardwell]

+Stephen Gibb thus may be related to the Raceflight guys claim that dshot 600 is not good at 32k.

[@emteehed]

not trying to sandbag, but 'Dithering' (within the imaging realm) is Addition of Noise. It's to 'Smooth over' (give a gradience) the 'Steps of Accuracy' created by digital colors. 8bits 16bits etc.... Like a Grader for Land construction. Stairs vs a Ramp Terraced mountain sides vs Natural form

[@cozmoz365]

Just watched your videos about one shot, multishot and dshot. I am amazed there are still ESC's being sold that do not support d shot out the box.

[@JoshuaBardwell]

Really, there aren't.

[@cozmoz365]

@@JoshuaBardwell good to hear. Guess I need to read more carefully.

[@MrSabram07]

Another good vid

[@1917VIL]

So helpful! Thanks:)

[@plowboyh6054]

Do they have a BER if so which one has the lowest BER they might look at positive ground to remove the noise floor. That is what we did in digital communication just an idea. PS loved it

[@TheRCAddict]

Thanks for the good info Mr. Bardwell. Would you consider coming to my school to teach? LOL

[@TheRCAddict]

Oh and just a side note, I just saw something about 900 and 1200!

[@binukpremaratne6303]

Joshua I know this is an old video but it would help if you could send the links to the wiki you said about removing the capacitor. Thanks

[@darryldarryl9801]

Thanks for the education. how would one determine if you've a lot of noise?

[@JoshuaBardwell]

Black lines in the video. Hot motors even with relatively low D gain. Honestly, it would be fantastic if we could get the ESCs to give us stats about noise. Such as beeping a code that indciates the relative signal quality for the flight after disarming.

[@darryldarryl9801]

Thank you

[@thebridgeninja]

Again, thank you! Learned bunches. Now if I could only learn how to fly lol!

[@KonstantinSharlaimov]

Joshua, you didn't mention one more thing - physical bandwidth of the signal and effects of wiring quality on the throttle signal. Badly done wiring might even render dshot unflyable while multishot will still be performing quite good. Ping me on Skype if you want to talk about it.

[@JoshuaBardwell]

I wish there was some way to get a solid metric over which protocol was performing better--other than flight performance, of course. I wish we could get reports of e.g. average jitter or DSHOT frame corruption rate. There's just no way for most people to know for sure what protocol is working best for them, other than exhaustive flight testing.

[@icerook1560]

OneShot 125's widths are 125 to 250usec. So if Looptime is less than 250 usec (4kHz) then at full throttle the FC outputs a continuous logic high signal to the ESCs which is NO Pulse so the ESC stops the motor. So basically if your pid loop is 4/2k why go to these higher protocols?

[@JoshuaBardwell]

Because the latency between the PID loop and motor gets lower, the shorter the motor pulse is. If the motor pulse itself takes up to 250 us to finish, then that is 250 us that the ESC has to wait to find out what the new motor value is supposed to be. If the latency is only 12 us, then that's a big improvement.

[@beeradfpv]

To me dShot is just just super smooth, requires less D. I lucked out as I had aikons that only required to cut the cap. I've switched everything over that can do it. I do have a revolt that I'll for sure be trying RF1 and 32k throughout to see which I like. Be hard for me to get out of DShot but I'll try it once released

[@1337flite]

+Joshua Bardwell - one really noob question - and it may be covered in a geneirc all about ESCs type video but I have not found it yet. Does a given BL Heli S version that supports D-Shot and is installed on an ESC also support the older protocols eg. Oneshot, Multishot? I.e. are their (usually) multiple protocols built into an ESC firmware binary? If you buy an DShot capable ESC can you use it with an older board that may not support DShot?

[@JoshuaBardwell]

+jtan163 yes. Blheli_s is completely compatible with all protocols at once.

[@1337flite]

+Joshua Bardwell - thank you.

[@Politicallyhomeless957]

I have a few quads now the one I am having the most questions about is the RTF I got from Horizon Hobby. The Theory XL has been a very solid entry into intermediate to advanced FPV. I scratch my head at some of the choices they made on the product however and was hoping maybe you might have some insight or ways I could improve the gear. It comes with 2206 2450thrust motors which are great but then they Use BL Heli (no S) ESC’s 30 amp that I only have been able to run one thot 120 since getting. I am on BF 3.2 and have anti gravity, PID’s and Rates all where I love them. I also changed to PT1 and turned off first two notch filters. I runs a SP F3 board and custom PDB that connects with one 7wire cable. Very reliable until recently. I tried switching to one shot 45 but the motors wouldn’t arm. Do I need to do something I CLI to switch one shot speeds? Last night I plugged in the quad and went to arm. Motors spin up then twitch and motor 2 caught fire and bad bad bad. Now I literally just got this back from horizon service 5 days ago, because it’s on warranty. When I got it back quad worked good for 10 packs and then last night I was going to hover test and this happens. I guess they fu$&ed something up.... oh man. Love these vids!

[@JoshuaBardwell]

Those ESCs don't support any motor protocol past OneShot125. If you set the motor protocol to OS42 and then lit a motor on fire, you're lucky they covered it under warranty. That's not a supported configuration.

[@Politicallyhomeless957]

I should have added more details. I tried one shot 45 qand it wouldnt arm. I went back to oneshot 120 and that was when the motor smoked. I believe it had to be faulty esc. I replaced esc and motor and it appears to be resolved. Thanks for the response. I cant believe they put those dinosaur esc's on this quad. Otherwise its really good with the exception of the esc's..lol

[@Politicallyhomeless957]

The crazy part was this quad just came back from service for bad electronics that was smoking motors without apparent cause. We tried swapping PDB, FC, Esc and motors and it still wanted start fires:0 I sent in for repair and I got it back like four days ago and then all i did was plug in lipo and arm and motor two went smoky. Im sure they will take care of me but its been kind of nuts..

[@Politicallyhomeless957]

Joshua Bardwell can I ask you do you think trying one shot 45 did something? Or was that esc probably just ready to go as I noticed my idle was a bit higher than normal? My other question is in the BL Heli config do you want your pwm min throttle to match your min throttle in BF? Mine is set at 1070 but is like 1033 in the BL Heli config. I just was not sure if I should leave them or have them match. Sorry for the questions and thanks again

[@ericklassen13]

Help please. I'm running DShot on the Lumenier 10A 4in1 however in Betaflight, my Motor Idle Throttle Value stays at 0. It wont save at any other value. Thoughts?

[@hungrysharkfpv1395]

I have read in forums that CAN is a better than DMA. Is this true and if so why? I thought digital is just digital. Great video by the way. I learned alot.

[@JoshuaBardwell]

+HungryShark FPV CANBUS and DMA aren't really comparable. DMA is internal to the processor. CANBUS is between devices.

[@hungrysharkfpv1395]

Thank you for the clarification, i must have misunderstood what i read.

[@surf1punk]

All of the Lumenier BLHeli_S ESCs support DSHOT600 without any modification, including the 4in1 if anyone was curious :) - www.getfpv.com/catalogsearch/result/index/?cat=13&manufacturer=196&q=blheli_s

[@mokhwasomssi]

good video!

[@RoboticSolutionsTECH]

Hi you answered my question partially in your part 1 video. In my hypothetical drone dive with a 1 volt throttle setting with a KV1100 engine with upward relative winds pushing my props to 2000RPM, will 1 volt still be supplied by the ESC? Or will the ESC cut off power (give zero voltage) until the props slow down to 1100RPM?? ESC might not care about RPM but it does care about speed of engine to be able to time charging of coils right? So if the speed is way beyond what the current voltage is what happens?

[@JoshuaBardwell]

The ESC doesn't regulate motor RPM at all. It could, if it were designed to do so, but it doesn't. All it does is output the correct voltage for the throttle signal.

[@RoboticSolutionsTECH]

So what does the ESC do to the motor in the above hypothetical scenario?

[@SSBelmont]

BF 3.1 has not been released yet, when I checked last week

[@JoshuaBardwell]

+SSBelmont 3.1 release candidate 1 is out as of today.

[@peterwoo2489]

I have a Racerstar V1 20A esc and the wiki said it would not work... I've been running Dshot 150 for a while now and it works just fine. It's the exact same as the Cicida V1 20As just for anyone interested! I hope the wiki guys add the info.

[@PaulHilgeman]

I have cicada V1s. They look just like the racerstar V2 PWB Layouts, but with solder tabs instead of wires. Have you tried removing the capacitor and trying DShot 300 or Dshot 600?

[@peterwoo2489]

I'm not sure if i should as the wiki only suggested that the escs can do Dshot150 for the Cicidas.

[@antzd]

I have the racerstar V1 20A with no modifications and its running DShot 300 perfectly with over 30 packs already. Unless you are tuning to the extreme edge there is very little perceptible performance difference between the various protocols. I did a test out of curiosity, default betaflight 3.1(SPF3) and went one pack on each protocol starting with oneshot125, then oneshot42, then multishot and finally DShot300. I could not tell a difference between them and even oneshot125 was flying just as well as the others.

[@JoshuaBardwell]

+Ant D the difference is mostly in tunability IMO. I don't think you'll feel it if you're not changing the tune.

[@ZeroFPV]

Why no Multishot?

[@Hotwire_RCTrix]

Great modern history lesson Joshua. Do you think this or even PID tuning, will be an issue with the AIO emergence? Do you think KISS will be the kiss of death for open-source flight control?

[@JoshuaBardwell]

I'm not sure how this would be affected by AIO boards. AIO boards seem to be going strong, independent of motor protocols. Many of the major players in the hobby today are closed-source. Betaflight is still going strong though. So is iNav and Cleanflight.

[@rizkyp]

how are dshot escs connected to the fc each connected to each own pin on the fc like "traditional" esc or it is connected in chained with its own address like I2C devices? and does dshot allows two ways communication?

[@JoshuaBardwell]

Same physical hookup as traditional PWM. One wire per ESC to its own motor pin. Not on a bus like i2c or CANBUS. Dshot is one-way communication. The goal with Dshot was to add digital to existing hardware, so backwards compatibility imposed some limits.

[@rizkyp]

Joshua Bardwell thank you.

[@davidgaspar1981]

blheli 16.5 has dshot built in ..... its released... no custom FW needed!!!! heads up josh..

[@MrFFFGGGFFF]

could you use the micro coax as your esc signal wires? would that help with noise?

[@JoshuaBardwell]

+Patrick Donovan the noise is not coming from outside, so no. The noise is induced by the internal reactance of the electrical system in response to voltage changes in the system.

[@MrFFFGGGFFF]

Joshua Bardwell ohh so that's why some osd pdbs always cut out when doing flips or other maneuvers that cause motors to speed up and slow down rapidly.

[@jasong3522]

Where can i see vide on how to properly calibrate my esc's? He stated turning throttle all the way up and then down but i have never had to move throttle. Am i dong something wrong?

[@JoshuaBardwell]

+Bearded FPV kzbin.info/www/bejne/pWSwmGBvgpWfaJY

[@jasong3522]

mine just says power on ( plug in ) and power off ( Un plug ) Flight battery that is.

[@maxxkax]

what about resolution in motor speed? can dshot send a command for example 45.33% speed. you mentioned the resolution of multishot in video 1. I think the possibility for dshot to send a very specific throttle speed will be the big advantage in flight performance.

[@JoshuaBardwell]

+Max Berkenstam dshot has 2048 steps, I think.

[@mrlazda]

Dshot can't send value of 45.33% speed to ESC, due resolution limitation, closest it can do is 45.31% (or 45.36%). As Joshua said Dshot have 11 bit resolution (0-2047 or 2048 values).

[@maxxkax]

47 of those values are "Reserved for special commands" [1] that leaves 2001 values for throttle where one of them is disarmed [1]. [1]: github.com/betaflight/betaflight/wiki/BETAFLIGHT-AND-Dshot My guess is that one bit is for negative versus positive command (3D flight). That gives 1000 values for resolution.

[@JoshuaBardwell]

+Max Berkenstam it would be stupid to throw away half your resolution on 3D when that feature is seldom used.

[@maxxkax]

Joshua Bardwell I looked at some footage of someone that had inspected the waveform, the resolution is 2000 my guess was wrong.

[@samik83]

When I switch to Dshot in the latest stable betaflight why can I still change the Motor PWM frequency if it's always synced on Dshot? Did they just forget to remove the option and it doesn't actually do anything?

[@JoshuaBardwell]

It's always synced, yes. Changing motor frequency doesn't do anything with dshot.

[@samik83]

Ok thanks for the reply. Was just setting up my first Dshot esc's here. I'm getting quite a bit of dead space on the bottom of the throttle. I've tried changing the throttle sub trims on my taranis, but if I add too much sub trim it just wont arm anymore. Throttle starts responding with the first line / notch on the taranis. I've gotten used to a bit less. Not sure how to fix this.....

[@tahosrfr]

Great video. So how/where do I find the info to use multishot?

[@JoshuaBardwell]

+tahosrfr blheli_s just enable it in Betaflight, recalibrate, and re check min_throttle. For regular blheli, flash the multishot firmware using the chrome blheli app first.

[@RoboticSolutionsTECH]

Hi please tell me what an ESC will do whenthe prop exceeds KV rating with the aid of external forces, ie when motor is at 2000RPM when only 1 volt throttle setting is applied to 1100KV motor. Will the ESC continue to pump in 1 volt?

[@JoshuaBardwell]

You've asked this question like three times now in three different places, and I've answered it twice. Please don't be offended if I don't answer it any more.

[@RoboticSolutionsTECH]

You didnt answer the question fully. Im even paying you now but still youre pretending that you answered my question when in fact you have not. If you read carefully and fully like an exam paper question you will understand that the question you ansered previously would only give you partial marks in an exam environment. This is not an exam but I hope you get the point and are not offended by my analogy. And yes I have posted this several times in different places because no one can answer it fully. FULLY. That means you give an answer as to what the ESC does to the motor at 200RPM when only 1 volt is given at throttle setting. Will it continue to give 1 volt or shut off until it slows down? DID YOU GIVE AN ANSWER TO THIS?

[@pauljohnson7538]

Why is there not more discussion on getting rid of the noise

[@JoshuaBardwell]

That's a topic for another video. Capacitors!!!

[@ZeroFPV]

Mattystuntz is using an extra cap for every single ESC. So it seems to be much more important for 5S and 6S setups as it is on 4S. ExplodingFist Recursion measured 30V spikes with 4S and 30A Little Bees. More S(cells) mean more volts and even larger spikes. I forgot what I wanted to point out, sorry! xD It's important to filter.

[@softart5235]

I have D-Shot 600,I can just click passed Multi-Shot to D-Shot 600 right?..........im using Multi-shot at present and change pid loop to 8 on both it sounds soo smooth,or is my lo-battery

[@leecyrille]

do you think the benefits of increased resolution of dshot 300 would still outweigh the reduced latency of multishot?

[@JoshuaBardwell]

+leecyrille good question.

[@jaswalmcpay7058]

How does the ESC (or 4in1) know what protocol you are throwing at it? I measure only from the FC, with cheap O-scope and see various different signals (S1-S4) depending on what I choose in Betaflight, but is the intelligence built into the ESC?

[@JoshuaBardwell]

Yep. It can interpret the signal and figure out what's coming in.