The pc communicates with the arduino via the serial port.
Arduino pwm fan controller.
It then becomes a matter of telling the fan pwm to raise or lower the speed based on the temperature.
I simply want to control a 4 wired fan or maybe several with an arduino board.
Pwm waves with various duty cycle are shown in the figure below.
Temperature based fan speed control monitoring with arduino.
4 wired fan control pwm control a pwm fan with arduino.
Firstly make sure that you fan s are pwm controller you can check this by making sure that your fan connector has 4 wires.
The arduino throttles the fans using pid logic and drives them through pwm.
The temperature and fan speed are reported through a 8 digit 7 segment display fitted on a rack mounted aluminium bar.
I had 5 laying around and thought mine as well give it a shot.
Many projects that use a temp sensor but never the most simple thing.
An inexpensive single small pass transistor like 2n222 or bd139 can be used here.
A low frequency pulse width modulation pwm signal whose duty cycle is varied to adjust the fan s speed is used.
There is a jumper for switching the power supply from arduino or the 12v input.
Pwm fan controller sketch can be downloaded here.
How to connect it.
Getting temperature values from a digital or analog temperature sensor on an arduino is fairly simple.
For this reason i used arduinos d6 pin pwm.
The ultimate project is to control the fan based on temperature.
Design schematic diagram is shown next.
I have been wondering about this project and how to control my 4 pin pwm fans.
So after that no electricity flows through it turning the fan off.
On the pcb there is a 5 12v input for the fan supply.
There is some information out there.
Control the speed of the fan.
It is efficient because the pass transistor is used as a switch.
As long as the cooling is on the red led is on when not cooling the green led is on.
In the above wave forms you can see that the frequency is same but on time and off time are different two applications of pwm control using arduino is shown here.
The system works by an application running on the pc checking the cpu temperature and checking whether to speed up or slow down the fans.
The blue led seen on the prototype board is just for verifying correct circuit.
The pwm controller accepts the control signal and adjusts the duty cycle of the pwm signal according to the requirements.
I o pin 9 on the arduino board is directly connected to fan control input and by reading the state of 3 push buttons on pins 2 3 4 different pwm values are sent to the fan.
