Hi Folks, new member here.
Ive been tinkering and learning arduino and absolutely find it a blast. The net and forums are full of good info, and the ideal for projects are almost limitless
I first begun learning arduino code, when multiwii first came out to fly multirotors.
Ive begun working on a simple project using a nano, but I have come up across a roadblock, and need some assistance from more seasoned members.
Simply put, I am controlling a 30N06L logic mosfet using a nano and a 10k pot as a “brightness” input.
I have all the coding figured out, and the code works very well, I figured how to get the serial monitor to work so I can read my A0 input value as I turn the pot.
I then have a basic code to turn the (0-1023) A0 value, into a basic Analogue write value (0-255) to pin D3
I then have D3 driving my 30N06L Mosfet in a identical schematic like this below. I am using it to drive a 12v led strip. I don’t have any need for current control with this led in this application… Just voltage 0-12v.
Heres my problem, I don’t get very good transition from off to low dimming percentage.
It is nearly identical to this issue in the first post. but there was no outcome.
I have verified that my D3 PWM value is working as expected, ive connected my oscilloscope to the D3 PWM output, and I do get 0-100% duty cycle from the arduino.
The problem is I don’t get a full dimming at the lower end of the command. I have the standard 10k pulldown resistor across the Gate and Source, and I have no erratic behaviour from the mosfet when it is commanded off (0%pwm, analogueWrite-0).
I get full power when commanded 100% (analogueWwrite 255), I get around 75% dimming when commanded around (Analogue Write ~175). The dimming smoothness works as expected, and I don’t get any pwm flicker…
Problem is, the Jump from a Analogue write of 0 to 1… at 1, I get about 40% dimming… approx. 6.45v to the leds.
I wonder if this is a limitation of the mosfet, I have also tested the setup with a IRL540 and get identical results. I also added a 220Ω resistor between D3 and the Gate, but it made no difference.
I even get the same issue if I completely omit the pot input, and manually type in a “analogueWrite 1” value.
Im wondering if I have to use a different pwm technique and change the default 490hz to something else.
Any help would be greatly appreciated.
This is the only road block im having right now, and I want to sort it out before I begin to add more channels and features.