MG996R + PWM 3V3 **SOLVED**

[livius]

Hi,

have someone connected succesfully servo MG996R?
I try but without success.
What i have tested already:

1. separate power supply for Wipy and separate for servo (GND connected between)

from machine import PWM
pwm = PWM(0, frequency=50)   #50???
pwm_c = pwm.channel(0, pin='P7', duty_cycle=0.5)

2. tested direct driving pwm from wipy to servo
3. tested with level shifting by 2N7000 on PWM signal

i can not got succesfull :(
With arduino it was so simple - i suppose that here should be same..
and i think that i have missed something obvious

[RobTuDelft]

@livius

From the spec sheets:

You seem to use a different duty cycle than is required?

I believe duty cycle is only 10 or 20 %?

[livius]

@RobTuDelft
yes - thats it - i supposed that it is from 0 to 100%

i have max right on

pwm_c.duty_cycle(0.034) 

i have max left

pwm_c.duty_cycle(0.127) 

thank you

[RobTuDelft]

@livius Great! What voltage is the final PWM signal? Are you just using the raw pin output?

[livius]

@RobTuDelft
5V i use 2N7000 NMOSFET transistor for level shifting for testing
for final i use smd BSS138