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Posted by vedantK | Apr 09, 2018 @ 08:11 AM | 1,420 Views
Hey Guys,

I am a newbee in making drones and I am currently working on a project. I wanted to know if its possible to send PWM signal through flight controller to ESCs.

As of now, I have a raspi which sends pwm signal to a spf3 flight controller. I checked the cleanflight receiver and the values received are within 1000- 2000us for yaw, pitch, roll , throttle as required. However, when I try to connect the esc to the outputs of flight controller and try to calibrate the motors .. nothing works .

Meaning that the pwm signal from raspberry pi is received fine but the same is not being sent to the motor escs.

If I try to control the motors from motor control through the cleanflight console, then it works but not on the input received from my raspberry pi.

What is the error you think? Can somebody please help me...... . Please let me know if something is not clear.

Regards,
V
Posted by vedantK | Mar 02, 2018 @ 12:12 AM | 4,938 Views
Well I am just try to build my own quadcopter and I have just started this month. I have a question regarding the battery to select.
Here are the components I have bought:

4X Racerstar Racing Edition 2205 BR2205 2300KV.
4X Racerstar RS30A 30A Blheli_S.
Gemfan Windancer 5042 5x4.2 Inch PC 3-Blade Propeller

The plan is to place a single microprocessor on my quad which I can control using my laptop. I am able to complete the calibration and turn on the motors.

However, the problem I am facing is like when I increase the pwm from 1000 in steps of 200 the motors begin the slow down. For example, after calibration if I change the throttle to 2000 then the quad does lifts off for some height but then the motors slow down.

I dont think there's a problem with the esc as a single motor just works fine with all configured speeds, but this only occurs when I power all the 4 motors.

I do doubt the battery as I had bought it hastily without investigating. It's a cheap 18650 Li-Ion battery pack 12V (3S) battery set which I think is not able to source so the required current. ??

Then I checked my motors and I guess racerstar consumes about 26Amps max current which would mean 26 x 4 = 104 A.
So by that calculation, I guess I would require a battery which can provide about 100A ?
I am thinking of buying a 2200 mAH 3S 40C/80C LiPo battery pack which can provide only about 22 x 4 = 88 A.
Now I am confused if I can operate the motors at max throttle?

Also how does the rating 40C/80C actually work? When does 80C come into picture as that would provide a current double of what it will provide at 40C.
Is it like a short burst of current at full throttle after which it will go down to 40C again ??