Problem with Servo pins

djokan · July 7, 2016, 1:03am

Hi,

I am using NAVIO+/RPI2, navio power module with 4s battery to power the board and SBEC servo pins because I have OPTO ESC.

When I was testing motor via c++ examples (Servo.cpp) I realised that when I connect motor to pins 1 or 2 it doesn’t spin, when I do same with pins 3 or 4 it spins (i changed pin numbers in code). Some pins are working but some pins are not working. What did I do wrong?

Regards,

Djordje

mr337 · July 7, 2016, 4:04am

I have barely looked into controlling Navio2 but did find some python code that should be quick to iterate all the servro pins. Looks like they have some code for the Navio, assume it works with Navio+.

github.com

emlid/Navio/blob/master/Python/Servo.py

"""
Provided to you by Emlid Ltd (c) 2014.
twitter.com/emlidtech || www.emlid.com || info@emlid.com

Example: Control the Servo machines connected to PCA9685 driver onboard of Navio shield for Raspberry Pi

Connect servo to Navio's rc output and watch it work.
Output 1 on board is connected to PCA9685 channel 3, output 2 to channel 4 and so on.
To use full range of your servo correct SERVO_MIN and SERVO_MAX according to it's specification.

Please note that this example uses Adafruit I2C and PCA9685 drivers.

To run this example navigate to the directory containing it and run following commands:
sudo python Servo.py
"""

from navio.adafruit_pwm_servo_driver import PWM
import time
import math

This file has been truncated. show original

This maybe enough to at least verify your hardware setup on pings 3 and 4 so you can figure out if hardware or software issue. Best of luck!

djokan · July 7, 2016, 4:29am

Thanks for helping,

I used this code to test pins Navio/Servo.cpp at master · emlid/Navio · GitHub
I think it’s same as your but it’s written in c++. With that code some pins worked, some not.

Regards,

Djordje

mikhail.avkhimenia · July 7, 2016, 1:46pm

Hi! Servo example was developed for usage with servos that work quite simple. ESCs, on the other hand, usually have an initialization sequence (like set the min throttle first, wait 2 ms, set max etc.). That’s why they may not work when you run this code.

djokan · July 8, 2016, 5:50am

Hi,

thanks for helping

I installed now navio APM and when I started motors on quadcopter, only motors on 3rd and 4th pins were spinning, those on pins 1 and 2 weren’t.

Regards, Djordje

mikhail.avkhimenia · July 8, 2016, 10:34am

Did you calibrate the ESCs?

djokan · July 13, 2016, 1:25pm

I didn’t calibrate ESC because i don’t have RC, i am using joystick but I think it works well. I recorded a video that shows you my setup , at the beginning I put motors on the right side on pins 3 and 4, motors on the left side on pins 1 and 2, when I armed and started only motors on the right side were spinning, then I swapped right and left side (pins 1 and 2 were right, 3 and 4 were left side) , and started motors again and now only motors on the left side were spinning. Here is the video: - YouTube

mikhail.avkhimenia · July 21, 2016, 3:04pm

You still need to calibrate your ESCs.