It’s not about the current. PWM is a control signal and the ESC shouldn’t put any load on that line.
It’s more likely about the voltage, as Robert wrote above. Pixhawk is a 3.3V system and that’s unlikely to change as all embedded systems nowadays run on 3.3V.
Using the74HCT244 is a hack, but should get you off the ground if you’re hell-bent on using EMAX ESC with Pixhawk. There’s probably 50 other ways to solve this problem, but this is what I had in my parts bin, and is a fairly simple solution, cause you don’t need any external parts like resistors, etc.
You can buy this chip online from a variety of places, and will also need a small breadboard to solder it to. You will probably also need a few extra wires/connectors to go to your Pixhawk/ESCs. There’s quite a few variants of this chip, with different shape, so be careful when ordering.
For HEXA/OCTO: the 74244 can supply up to 8 ESCs, but my diagram shows only enough lines for a quad. To supply additional ESCs, the inputs will be on pins 17/15/13/11, and associated outputs will be 3/5/7/9. You will also need to ground pin19 to “enable” these additional lines. The triangles on the diagram point from input to output.
Soldering skills: moderate
NOTE: I seriously doubt this is something either Pixhawk or EMAX can solve with a software fix.
Hi,
in other forum, i read or someone propose this solution:
diydrones.com/forum/topics/getti … _com_forum
Someone check this one? If yes, this solution to remove resistors make work emax in pixhawk?
thanks
Hi,
I tried something similar to this by wiring in an Adafruit 8-channel bi-directional logic level converter (coolcomponents.co.uk/8-chan … b0108.html). I was using 5V from the BECs for both sides, assuming that it would act as a line driver.
When plugged directly into the servo, it works fine, and when plugged into the pixhawk, nothing happens. This is the same behaviour without the Logic Level Converter.
I’ve asked Yin Yan Models for advice as to which components need removing, but no luck with a response yet.
Setup:
Pixhawk (chinese version) with Arducopter firmware
EMAX BLHeli Series 20A ESC (yinyanmodel.com/En/ProductView.asp?ID=380)
Any suggestions greatly appreciated!
Regards
Gareth
Just soldered that chip, when connecting baterry ESC turns to programming mode.
Can’t understand, where i made a bug?
Just soldered that chip, when connecting baterry ESC turns to programming mode.
Can’t understand, where i made a bug?[/quote]
+ UPD
Works when pressing safety switch when plug in battery, but i can’t make calibration in this case…