Calibration of 4-in-1 Hobbywing Skywalker Quattro 20A ESC WI

Hardware Multirotors
1

Hello all,

I am very much a newbie to RC and quadricopters but I’m working with a group of fellow students on constructing an autonomous quad for a university project. We are currently performing our initial setup.

We do not have an RC transmitter and whilst we could beg/borrow one, we would like to know, first, how to go about calibrating the 4-in-1 ESCs without one. I have read online that it is possible to do this (although the commenter didn’t say how) but that it is dangerous since for a first flight you would have no manual override in the event of mis-calibration(s) causing erratic behaviour, however we plan to tether the quad in test flights to overcome such an issue and then fine tune it with/without an RC transmitter (depending on whether we can get our hands on one without purchase).
So, what is the method for performing this calibration through the APM 2.6 in Mission Planner/APMPlanner 2?

One more question:
We would also like to know how to incorporate an Arduino code program into a weypoint Flight Plan in Mission Planner/APMPlanner 2.

A bit more background:

We have built up the frame (except for the landing gear, which will be Araldite-d on soon), mounted the motors, prop savers and props, and connected the electronics to the latest versions of Mission Planner and APMPlanner 2 on the laptop by USB cable, however we have not connected the electronics to the motors.

As soon as the quadricopter has left the ground there must be no further human intervention and it must autonomously carry out a mission to cross a generic flight zone and then enter a target area. It must have a payload release system and must deliver a water payload accurately over an imaginary fire in this target area and then return to launch. Throughout the flight it must be able to stay within a geofence (or if it does exit, it must swiftly and in a stable manner return to the geofenced area) and it must be able to cope with rain and gusts of wind up to 8m/s. Our permitted budget for the entire project is £250 and we are currently JUST on budget.

In terms of components, we have:
3DR (clone) APM 2.6
3DR uBlox LEA-6H GPS with compass
3DR Power Module
3DR (clone) Radio Wireless Telemetry
Turnigy 3S 20C 3300 mAh LiPo battery
Hobbywing 20A Skywalker 20Ax4 UBEC 4-in-1 Brushless ESC
4 Turnigy Aerodrive SK3 - 2830-1020kv Brushless Outrunner Motors
4 10x4.5 Black Rubber Propeller Prop; 2 CW, 2 CCW
4 Prop Savers
’Thermal Knife’ circuit as per Bovine Aerospace
Kilner strainer funnel
Custom, self-built aluminium frame
Coat hanger landing gear
3D printed anti-vibration mount as per Omnimac
3D printed GPS stalk mounts
LED flasher unit

With regards to our second question, we would like the quad to automatically fly by waypoints to the target area, hover and release the water payload. This latter process is controlled by a piece of Arduino code written by Bovine Aerospace and made open to the public. It is this piece of code that we would like to incorporate into the Flight Plan in Mission Planner/APMPlanner 2.

We would be extremely grateful if the members of this community would help us out.

Yours faithfully,
FlyPhi

2

Firstly, I don’t think flying a mission without some way to manually override the quad is not a good idea. In case of a GPS glitch, you quad might fly away, and you’d have no way of stopping it. There are radios for as low as 20$, if you can, i’d definitely get one.

But if there really is no way of doing that, And since you have the telemetry module, You can use a cheap USB gamepad in place of an RC Radio. There is a section in APM website detailing the process. I tried it once just for the heck of it. Due to latency, it’s not really easy to control a multirotor with it. RC Airplane? No problem. But multirotors require constant stick input. And having even 200ms delay makes flying them, especially close to the ground a nerve wrecking experience.

If you still want to go that way, you should also configure your telemetry radio to the “low latency” mode. You should be able to see that setting in mission planner.

For calibrating them using a gamepad… That might be problematic. You see, in order to put the APM to ESC calibration more, you need to set your throttle to max and then power APM up.

Problem is, in order to use the gamepad, you first need to connect to it with Mission Planner and that happens only after APM is fully booted up. So this approach clearly won’t work.

You can probably manipulate what the PWM your APM sends to each individual ESC manually via mission planner. But i don’t have a clue, how such a thing can be done. Maybe someone more knowledgeable then me might help.

If you have an Arduino around, you can use it to set the PWM range of the ESCs too. An arduino nano costs about 5-6$ on ebay(inc shipping) and i bet someone in your school already has it.

I still think the best thing to do is to get a 20$ radio.

Good luck with your project. I hope everything works out.

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