we read recently of the problems that some esc driven by pixhawk.
maybe the refresh rate of Pixhawk is too high for these esc’s, maybe the PWM outputs 3.3 volts are the cause, (those older 5 volt APM does not seem to cause errors), someone in Italy has solved the problems of sync with a level shifter between the output of the pixhawk and esc (Afro slim) … etc…
My question for developers:
In arducopter superb wiki, I see a list of the best selling radio (Turnigy. Graupner - Futaba etc…) and the settings to be applied to work with the hardware / software APMcopter.
Similarly, the 3drobotics, could make a list of the most popular and best-selling esc in the world, and say which of these are “certified” for use with Pixhawk ?
I don’t see 3DR’s responsibility to do that. I see the responsibility with the ESC manufacturers.
3DR does offer ESCs which are tested with their autopilots.
I agree, there is no responsability of 3dr in this, the cause of these problems could probably be SimonK firmware or esc’s with old atmel8, but I think the end user would approach the PixHawk with greater confidence if they knew what hardware to use.
I know that in the official 3DR store there are esc 20a (only 2/4s !!!) branded 3DR, but it is a bit limiting to say to use only those with the PixHawk ! Can’t I use, without issues, best and world’s best selling 30a or 40a esc’s to carry and fly with my professional equipment or very high payloads ?
Pixhawk is a beatyful ed amazing platform, more powerful than APM, but I see in international forums that many people talk about the problems between esc’s and PixHawk, and people who have not yet purchased it simply decide not to buy it. I believe for to compete and surpass all other brands worldwide (DJI in primis), today 3dr should tell us (end users) something more.
You are free to start this list! Join the Wiki Editor group and contact Alex to get a user account for the docs Wiki.
The problem is - if 3DR would officially publish such a list, there would be 2 options to get the data:
[ol][li]Test themselves[/li]
[li]Rely on user reports[/li][/ol]
[ol][li]Testing themselves would be a huge effort in time and money. I don’t know, if you realize, HOW many ESCs are actually out there and “best selling” changes practically every week. A good example are those AfroESCs from Hobby King. HK came out with them and everybody is just buying them like crazy… Additionally, especially with the stuff from China, there are sometimes pretty big changes in product quality, so the testing would have to be somewhat repetitive or continuous.[/li]
[li]Trusting user reports could pose a liability problem. 5 users say, ESC XYZ works fine. The 6th user uses it, has a failure and his 7,5kg Octocopter with $4500 worth of camera crashes from 100ft on top of a $1m luxury sports car. The user will surely put some blame to 3DR and so might a court, if 3DR didn’t sufficiently test the ESC themselves.[/li][/ol]
So, no, I don’t think, there will be an official list - but I could imagine a user-maintained list in the wiki. As I wrote - you are free to start one!
Your idea for an ESC page sounds great. If you’d like to become a registered wiki editor, please email me at alex@3dr.com, and we can get started creating your account.
I will not conceal that when I used naza before knowing APM, I just looked at this list (a few years ago it was less dense) to choose motors and esc and flies quite and smoth.
This sound like a very good idea for end users.
I realize that by 3dr could be costly to do such a thing, and then the great idea of the wiki could be started right from the many beta testers and developers 3dr, that every day stress to their frames, motors, esc, to test new software release to verify that everything is OK.
For their tests, use they, with Pixhawk, only 3dr branded hardware ?
For my part it would be an honor to contribute in some way to the world arducopter.
Like “compatible list of Naza” I can write only my experience, not tests with every conditions or signal tests with oscilloscope (I have not).
My initial proposal (no controversy), was to delegate this hard work to 3DR on those esc considered (by 3dr) the best on the market, not all esc in the world, or I have another idea for 3dr:
Add in the official store, in addition to the ESC 3dr 20a 2s/4s, other types of esc with greater current (30a 40a) and more power options (5s-6s). This would be a less onerous job for 3dr and allow users to choose and buy with confidence according to different needs and equipments.
For Craig.
I readed here: baronerosso.it/forum/modelli … ost4219739
from user “sonico”, he had issues sync with afro20 slim and Vrbrain.
measuring the output PWM (3.3 volts), he found that VrBrain out PWM, comes with a minimum signal of 80 mV and a maximum signal of 3.32volt, so only 0.32 volt more to run well for esc (level0 <1V and level1> 3volt). (I think signal PWM from Pixhawk colud be similar to VrBrain)
In conclusion, placing a level shifter between the output and PWM esc he claims to have solved the problem of sync.
In particular, his selfmade shift level, allow a signal PWM between 0,36 volt and 4.64 volt and seems this could have led to resolution of issue sync.
This is my summary, if you want more details you can ask him.
I feel I can contribute by helping people to focus on the right aspects during troubleshooting. After having tried all ESCs reported as “not working” myself successfully, I did a little write up to be referenced in the future. It tries to be a helpful troubleshooting resource but also serve as reference. Note that you can register yourself on the page and edit it if you feel parts of it need updating.
Pixhawk works with every ESC out there that works with a normal RC receiver. Really. Because it sends the same type of signal.
The flight stack has to ensure that initialisation requirements for the ESC are met. The two most popular: 1) requiring a low pulse, e.g. 900 us or 2) timing out after a few seconds without signal. The native stack eliminates both by sending a 900 us pulse at boot and raises this to about 1100/1200 when armed. It does this only for multicopters.
People need to get their wiring right. Always connect signal and ground. Check your ESC type to decide how to connect the +5V line. Pixhawk will never mind how you connect it, but your ESCs might kill each other if wired incorrectly.
Basically you can get away with using the power ground as the signal return with the APM but you cannot do that with the Pixhawk. You must connect both the signal and the signal ground in order to make the ESC work, otherwise the PWM signal looks like this.
I thought the issue wall all centred around esc’s with SK firmware and certain pancake motors. I was made aware of this right after buying a bunch of Sunny Sky 4108’s and Afro 30’s lol! Basically the worst reported combination with the Pixhawk for sync problems. And I can verify that, the sync is awful. The whole point of this setup (with a Tarot 650) was simply to test the PK before putting it into one of my large mapping units. Which just happen to all use SK esc’s and pancake motors (Foxtech 6135 and 5010). Guess what? Loaded the latest SK firmware AfroNfet V2014-03-06 and the sync issue is completely gone! So that takes care of the Afro units, now I’ll need to figure out how to update the Foxtech DYS40lw which I use a lot with DJI autopilots (can’t wait to dump that stuff!).
Are you also using a ground wire for the signal? Or only a signal wire? Have you had any more sync issues? I’m completely willing to buy whatever I need to get a solid copter. I am pretty shocked by some of the 3DR comments on here. I would be hard pressed to buy 3dr products again, their complete disregard for their customers is astounding. If 3dr would simply endorse 1 or 2 third party escs SINCE THEY ONLY SELL 20A ONES themselves that would be of a great help. But apparently thats not 3drs responsibility to help a customer get a working setup using their flight controller.