First of all I would lile to thank you all for your help, you are giving me a lot of assistance for my experiment. I would like to test two things, one is to change the frequency of the PWM from the arduino and test different ones to see if I see changes or smoother PWM increases/decreases.
Lastly I would like to try a mosfet instead of a BJT, do I need to make.any change on the schematic for this last test?
if I decrease it from 255 to 0 the motor around 120-130 stops and makes even a kind of noise, like a pitch.
That is normal when you control the speed of a motor with PWM.
PWM does not generate a variable voltage like the output of an adjustable power supply. It generates digital pulses that change in width.
Here is a good explanation about PWM, I think you should read it:
one is to change the frequency of the PWM from the arduino
Have you read the Arduino reference about analogWrite?
Lastly I would like to try a mosfet instead of a BJT, do I need to make any change on the schematic for this last test?
For testing the present circuit will be OK
Hello Jim,
I just read the article and there is one note that I didn't fully understand.
The PWM outputs generated on pins 5 and 6 will have higher-than-expected duty cycles. This is because of interactions with the millis() and delay() functions, which share the same internal timer used to generate those PWM outputs. This will be noticed mostly on low duty-cycle settings (e.g. 0 - 10) and may result in a value of 0 not fully turning off the output on pins 5 and 6.
My question is, if I use these pins I can extend the range from 0 to 255 that my motor is running?
For example if my motor runs from 160 to 255 on pin 9, at pin 5 and 6 I can run it from 160 to 255?
That warning simply means the the PWM duty cycle on pins 5 and 6 will not be accurate when set below 10 and may not actually be 0 when you set it to 0 but probably will be very close to 0
So everything is working fine for my motor.
Now I have another question about the MT3608, do you think it is possible to use the EN pin with PWM to control the output voltage?
For example, if I take out the potentiometer and put the R1 and R2 resistors to output 12v can I decrease it digitally with logic?
I read somewhere that I would still output the Vin tension, but if for example I put a kind of switch in front to turn off the voltage in?
From this schematic, there is anyway to filter out the input to the motor?
I was thinking that maybe this could be my solution if I can get a stable dc voltage instead of an average voltage from PWM (on-off state).
Hello, I just would like to inform you guys that I found that the solution of PWM is the one that worked for me.
I manipulated the feedback input of the boost converter, with pwm through an RC filter.
There is a detailed article from analog devices that helped me a lot.
Have a good day and thank you all for the help.