Waypoint mission testing for 100 kg payload drone

Dear guys, first of all thanks for the useful advice we had in the PID tuning. We are now testing the way point mission for the 100 kg drone 40 kg payload and 60 drone…

In this mission we have used a RC and servo chancel. and it works fine in loiter mode with pass through value 1. And when starting with loiter we move the craft to eg 4 meter and then turn to auto. The pump works neatly at pos 2 and sometimes stops at WP4 but also sometimes continues beyond that point over the mission. Of course we can turn it down on the TX. But first can someone tell me why we should not put it at 0 value iso 1? As I understand that 0 would be the mission position? Next is there an explanation the experienced users of spray pumps can give on why sometimes the pump it is not stopping at the next WP as it is supposed to do? Let us know? We do this testing with a 80 by 80 cm drone so we can also test eg resume mission and other parameters with more safety!

Best, Winfried

I am bit confused by the question you are posing. There seems to be a lot of things that you are asking and I think it would be best to focus on one at a time. Can you please try to re-explain one of the issues you are facing. Sorry about this - I just don’t understand what the question is.

Dear Manav, the question can be rephrased simply: if in auto flight: is the Do_set_servo command- action stopping normally when reaching the next waypoint normally. Or is it continuing the whole mission unless a new command is given with a lower PWM value… Currently I experience the last situation when testing.

Best Winfried

A new command has to be given to change the PWM output as you have seen.


When you give a Do_Set_Servo command the new position is held until another Do_Set_Servo command is used. So if you set the servo to 1100 at Waypoint 3, it will stay at 1100 throughout the rest of auto mission until another command is given (either with another Do_Set_Servo or by the transmitter).

Now, it is important to note that if you have a transmitter connected with a channel that is set to RC pass-through for the servo - the transmitter’s value will always override. This is because your transmitter is basically tell the servo to go to that position multiple times per second. So if you set a servo to 1100 in an auto mission (but your transmitter has the pass through channel at to 1500), the servo will quickly switch back to 1500 almost instantly. Does this make sense?

Dear Guys, thanks to let us know it works like this indeed. Our initial thought was that if we do a spray mission we would open the pump (or valve) for the long stretches and stop the spraying when turning for the other stretch. It can of course be done by adding one command to stop and another one to start on the next stretch… We must find a way to do this automatic… Anyhow thanks for the reactions again!

Don’t know if it helps much. But you can use this command to set the spraying for a certain amount of time.

Yes Manav, I went through the documentation and found that option. It can relieve the issue somewhat. Another option that I was informed on, is that you can do a spiral mission. Then we can leave it on continuously. I have to check that as on my version of MP could not find it! Are you also using the drone for spraying?

Best Winfried

Hey! I do not do any spraying with my drones, mainly stick to mapping and payload delivery missions. However, I would assume that a mapping mission is very similar to a sprawling mission - from a MP perspective. I do use some of the Auto-WP features a lot (spiral, grid, corridor, etc.) and have found them to be a quick and easy way to setup my missions. They are not perfect for my needs, but accommodate 99% of the features I need - thus I tend to use them at first and then perform slight modifications to get my final mission.