I am in the process of building a quadplane in the 4+1 configuration.
The question I have is regarding ESC’s. My four brushless motors need 40A each which is why I am going for a 4-1 ESC like the SpeedyBee BLS 60A 4-in-1 ESC.
The problem is that my flightcontroller, which is the MATEK F405-VTOL, has its own on-board power distribution board which I dont think is safe to connect to the ESC since it would draw way too much current. Is it possible to connect the speedybee BLS to the flightcontroller itself and leaving the vbat and current sense pads unused by only connecting controlpins and ground to the flightcontroller? while I know its possible to use ESC telemetry on other ESC’s it is not possible on this one.
I know this might be a trivial quistion but I find it hard to find concrete answers scouring the internet.
You’ll need to connect battery power to PDB because it has the voltage regulators for the controller, even if you don’t use the PDB for the ESC. It’s also how the servos will get their power.
How big of a plane is it? You could use a tool like ecalc to figure out what you could expect roughly for current draw. Do your motors “Need” 40amps or are they rated to 40amps? (I’m not doubting, just asking for clarification)
The F405 VTOL PDB says:
Support continuous load of up to 100A on ESC pad near the current sensor resistor
Support continuous load of up to 30A & peak of 50A on each ESC pad of Quadcopter
Alright, I think I might consider trying that. Although still a bit concerned. But would you happen to know if it is at all necessary to connect the vbat and current sense in order for the ESC function? from what I could gather it isnt. As long as the flightcontroller have a way of measuring battery voltage. (Although battery usage would not be accurate)
If you connect the Bat+ terminal on the PDB that will give you Vbat so you’ll have voltage data. But if you are running the ESCs in parallel to prevent overloading the PDB then you won’t have current.
It will fly without current data. It’s not required. However, as you point out the battery usage won’t be accurate, and you’ll also give up the ability for COMPASS_MOTx to be set up to create dynamic compass corrections based on overall current load. Maybe not the end of the world depending on your build.
And no, the ESC doesn’t care if you connect Curr and VBat. That’s just data out as far as it’s concerned.
Firstly, thank you so much for your response! it is wonderfull that there are people like you who take time out of their day to help others.
Superb. For now the drone is to be used as a proof of concept, so it is not that important. I just wanted to make sure that I wasnt doing anything extraordinary stupid.
one last again newbe question. Do you happen to know if a standard m8n gps would work with the MATEK F405-VTOL flightcontroller?
Nice. Mine is of an unknown brand so fingers crossed, that it will work out. (I had originally been given a pixhawk 1 which turned out to be completely dead).
Did your flight go as planned? And do you have any advice on things I should be aware of when setting up the f405 up for the first time ?
Again, I really do appreciate your time. It awesome to see such an active community.
My biggest advice is read the wiki for VTOL. There are lots of options and configuration choices for VTOL so it can get complicated. 4+1 is pretty straight forward (comparatively) but take your time and don’t be in a rush. Don’t plan to try fixed wing mode on the first flight. Get the quad portion going well first, then try fixed wing.
It’s a nice touch now that F405 can run the quick tune on VTOL so that helps a lot.
That sounds reasonable. I will try and go through the wiki throughout the setup process methodically. My only goal is to get it to hover, as I will need some training on an actual rc plane before trying on my drone.
Thank you again. Your help have been insightful and given me some more hope for the success of project.
I’m sorry to reopen this thread and message you again. The reason is, that I’ve run into some issues with my f405 vtol. It seems that my altitude readings fluctuate/drifting quite a bit. I was wondering if this is considered normal and if it much it will affect things like qhover or qstabilize? If so, should I go for something with a better barometer ?
How much is it moving? If it’s only a meter or two when it’s sitting on the bench then that might be what you get. It won’t impact too much during flight because the EKF is looking at other data points. Yes, it may wander up and down a bit but if the rest of the tuning is dialed in it shouldn’t be too bad. If you want rock sold, DJI style hover, then you need to add in some kind of laser range finder.
yeah it seem to be fluctuating around approximately ±2 meters. Although when I move the flight controller upwards, the reading changes accordingly, but then it starts fluctuating again. This occurs both with and without EKF3 enabled, as well as with and without GPS. Another note, when the GPS is enabled it starts to drift even worse (contionues well into the negatives upwards of -60m). I have attached a barebones parameter file used during testing.
Barometers are subject to a lot of errors (temp changes being a big one that isn’t always obvious). So they wander. At this point I’d say try to hover it first then see if it’s really a problem. I’m flying the same FC and GPS. Yes, the height jumps around when I’m on the work bench. It hovers fine when I take it outside.
Okay that’s actually quite a relief. I haven’t tried to hover as of yet but I am planning on doing it next week after getting the center of gravity done.
You have no idea how much you’ve helped. I was on the brink on buying something like the h743
