For quite a while, people have been wondering
- When will ESCs be readily available with SimonK firmware pre-flashed?
- When will some easily obtainable ESCs support I2C, so that flight controllers can read motor status?
HobbyKing has provided the answer, with the newly introduced AfroESC. It's licensed from both SimonK and timecop.
I've started collecting information here, and will update when more information is available.
http://eastbay-rc.blogspot.com/2013/07/afro-esc-simonktimecophobbyking.html
Highlights:
- SimonK preflashed
- Open Source software
- licensed
Comments
If you're using the ESC's BEC, shouldn't you use ALL of them? In most applications, four ESCs should give you 2A, yes? Before I knew better, I used a power distro board which only hooked up the rear ESC on my quad to power the APM. No wonder my quad would pitch backward when that ESC hit its heat cutoff. Ever since I started connecting all 4/6 ESCs to power the board (or even better, use the 3DR power module), I haven't had that problem.
"I wrote 3DR radio, MinimOSD and a 2way RX, e.g. FrSky or OpenLRS and maybe some additional sensors... I can't find it spontaneously but I recently read that 3DR is shipping the APM 2.5 with a 1.1A fuse since a short while, instead of the 500mA fuse, because there were some problems with "full" configs."
Don't forget, that "full configs" could easy drive lots of servos (APM could fly in plane with... Let's say, 6 servos).
On this one (APM, minim, RX, telemetry) you get something like 0.3A drain.
Even so, you on multis you connect linear BEC's together, so on quad you have 4x0.5A = 2A capacity. More than enough for 95% of setups.
And if that's not enough - separate BEC come to rescue (seriously, do not expect that 30g ESC will drive 6x full size servos + motor, eh?)...
Anyone who says that 0.5A (true rating - not overloaded "2A" stated on most cheap ESC's) is not enough for most multicopters should think again. And again.
Garry,
that would be a messy business, splitting cables (pulling the +5V line from the ESC plug, putting cables and such. Using a dedicated BEC for each component would also add to the (in-)efficiency losses.
Scott has a point, but when following his philosophy, there's no need for a BEC in the ESC at all.
Hence my opinion that a 500mA BEC in an ESC is rather useless, unless you have a very simple copter which only has a flight controller with no additional components.
Stefan,
Assuming you ground everything properly, couldn't you power your autopilot from one ESC, your OSD from a second ESC, and your RC receiver and telemetry radio from a third and possible fourth ESC? My vote goes to using a dedicated BEC for all of them, though...I am more frightened of ground loops than RF interference.
@Scott
I completly argee with you, I don't understand the fuzz about the LDO.
I would be interested in the hardware design (or a photo of the other side) there are no via's visible.
They used these fets:
http://www.vishay.com/docs/64730/sir158dp.pdf
I ordered a set of these to run on a tricopter and I will have to run a uBEC as 500ma won't run the FC, servo, and receiver. I posted up in the Afro thread on rcg asking for comment from SimonK and Timecop on the choice of 500ma BEC on these and hope to get a response.
Someone replied speculating these are LDO type linear regulators. Not knowing what that meant a quick google yielded some interesting info. "The advantage of these regulators is that there’s minimal to virtually no interference generated to confuse the receiver and radio." So I think if this is true running these ESC's and a shielded uBEC will cut down on RF splatter significantly, which has some nice benefits.
I don't power anything but my motors off of the ESCs. The APM and everything else is off a dedicated BEC. I could care less what they have for a BEC in these. For the money, and for use in a multi-rotor, this seems close to ideal.
There is already a 30 Amp switching power supply in this device, I can't see that another 1 or 2 Amp switcher would constitute much of a problem from an emissions point of view. But perhaps the designer was more concerned about conducted noise on the 5V output, which can be hard to suppress. I think it is worth exploring the reasons for the designer's choice before dissing it too hard.
Andrew
I fully agree with Stefan, it's really idiotic to have only 0.5Amp BEC in this ESC, generally even 2Amp BEC is also considered inadequate and people prefer at least 3Amp.
@Cliff-E, I'm no expert on power supplies, but it is my understanding that the high frequency off/on pulses of a switching power supply generate radio frequency noise. Many factors go into range, but it does seem one easy step is to use linear power regulators, of course at the cost of some efficiency.
And as R_Lefebvre points out, such a small loss when you're in a multirotor platform will not be a lot overall.
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